CN102299831A - Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment - Google Patents
Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment Download PDFInfo
- Publication number
- CN102299831A CN102299831A CN2011102897075A CN201110289707A CN102299831A CN 102299831 A CN102299831 A CN 102299831A CN 2011102897075 A CN2011102897075 A CN 2011102897075A CN 201110289707 A CN201110289707 A CN 201110289707A CN 102299831 A CN102299831 A CN 102299831A
- Authority
- CN
- China
- Prior art keywords
- server
- state
- switching
- service flow
- nat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 57
- 238000013519 translation Methods 0.000 title abstract description 6
- 238000001514 detection method Methods 0.000 claims abstract description 79
- 230000005540 biological transmission Effects 0.000 claims abstract description 5
- 238000012423 maintenance Methods 0.000 claims description 52
- 230000009471 action Effects 0.000 claims description 44
- 230000001360 synchronised effect Effects 0.000 claims description 12
- 230000004044 response Effects 0.000 claims description 2
- 230000008569 process Effects 0.000 description 7
- 239000000523 sample Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
Images
Landscapes
- Computer And Data Communications (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
The invention discloses a method for detecting invalidation of group members of an internal server and network address translation (NAT) equipment. The method comprises the following steps of: if the NAT equipment receives an ICMP (Internet Control Message Protocol) target non-accessible message sent by internal network equipment, determining a non-accessible server according to the message, switching the state of the server to detection, detecting whether the server is accessible on three layers, and if not, switching the state of the server to invalid; otherwise, switching the state of the server to stale, marking a session corresponding to service flow distributed to the server with an S, switching the state of the server to delay, setting a first timer for the server, switching the state of the server to valid if the session with the mark S is switched from open state to ready state or three times of handshake of a TCP (Transmission Control Protocol) specific to the session with the mark S are successful; and otherwise, switching the state of the server to invalid. Due to the adoption of the method and the equipment, the invalidation of group members of the internal server can be detected.
Description
Technical Field
The invention relates to the technical field of communication detection, in particular to a method for detecting the invalidation of an internal server group member and Network Address Translation (NAT) equipment.
Background
A plurality of servers in the NAT internal server group provide certain service to the outside together, and load sharing of the internal servers can be achieved. The basic principle is that a virtual IP address is published externally by the NAT device, and when a client accesses the virtual IP address, the NAT device maps the virtual IP address to a certain member of the internal server group through a certain HASH (HASH) algorithm.
Fig. 1 shows an example of a networking in which an existing internal Server group commonly provides a certain service to the outside, as shown in fig. 1, when a Personal Computer (PC) 1 accesses a virtual IP address 212.1.1.2 published to the outside by a NAT device, it may be mapped to a Server (Server)1 by NAT translation and then a PC1 is provided by a Server1, and when the PC2 accesses the virtual IP address, it may be mapped to the Server3 by NAT translation and then a PC2 is provided by the Server3, thereby realizing load sharing of the internal Server.
The current address mapping method is to fetch the message contents as: counting a HASH value by the source IP address, taking the value and the number of the internal server group members as a module, and adding the obtained value serving as an offset and a base value of the internal server group configuration table to obtain a corresponding internal server group member.
The problems of the method are that: if one member of the internal server group fails, i.e., cannot provide the corresponding service, the NAT device cannot sense that part of the accesses are shared to that member, resulting in that these accesses are not serviced, even if there are other active server group members present at that time.
Disclosure of Invention
The invention provides a method for detecting the failure of an internal server group member and NAT equipment, which are used for realizing the detection of the failure of the internal server group member by the NAT equipment.
The technical scheme of the invention is realized as follows:
a method of detecting failures of members of an internal server group, the method comprising:
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, determining an unreachable server according to the message, switching the state of the server into detection, detecting whether the three layers of the server can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state or TCP three-way handshake aiming at the session with the S mark is successful; otherwise, switching the state of the server to failure;
if NAT equipment receives RST messages sent by intranet equipment, an unreachable server is determined according to the RST messages, the state of the server is switched to be stable, when a service flow is shared on the server, an S mark is added to a session corresponding to the service flow, the state of the server is switched to be delay, a first timer is set for the server, and before the first timer is overtime, if TCP three-time handshake aiming at the session with the S mark is successful, the state of the server is switched to be effective; otherwise, the state of the server is switched to failure.
When the NAT device receives an ICMP destination unreachable message sent by an intranet device, the switching the state of the server to invalid further includes: setting a second timer for the server, and returning to the action of switching the state of the server into detection when the second timer is overtime;
when the NAT device receives an RST message sent by an intranet device, the switching the state of the server to be invalid further includes: and setting a second timer for the server, and returning to the action of switching the state of the server to the stable when the second timer times out.
When the NAT device receives an ICMP destination unreachable message sent by an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further includes:
the NAT equipment determines whether a corresponding session exists according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if so, the NAT equipment switches the state of the server into a detection action; otherwise, keeping the state of the server unchanged;
when the NAT device receives an RST message sent by an intranet device, after determining the unreachable server, before switching the state of the server to a standby, the method further includes:
the NAT equipment determines whether a corresponding session in a synchronous state exists or not according to the quintuple of the reset message, and if the session exists, the state of the server is switched into a detection action; otherwise, the state of the server is kept unchanged.
The method further comprises:
when the NAT equipment receives a service flow first packet, a server with an effective or stable state is selected from the internal server group, and the service flow is shared to the selected server.
The method further comprises:
when the state of the server is found to be switched to detection or delay or failure, selecting a second server as a standby member of the server from the servers with the state of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers;
when receiving a first packet of a service flow, the NAT equipment calculates a server for sharing the service flow according to a preset load balancing algorithm, judges whether the state of the server for sharing the service flow is stable or effective, and directly shares the service flow to the server if the state of the server for sharing the service flow is stable or effective; otherwise, the service flow is shared to the spare member of the server.
A method of detecting failures of members of an internal server group, the method comprising:
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, determining an unreachable server according to the message, and switching the state of the server into detection, if the server is found to provide UDP (user datagram protocol) service to the outside, detecting whether three layers of the server are reachable, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state; otherwise, switching the state of the server to failure;
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message or an RST (quick response request) message sent by intranet equipment, determining an unreachable server according to the message, switching the state of the server to detection, if finding that the server provides TCP (transmission control protocol) service to the outside, performing TCP three-way handshake with the server, if successful, switching the state of the server to effective, and if failed, switching the state of the server to invalid.
When the NAT device receives an ICMP destination unreachable message or an RST message sent by an intranet device, the switching the state of the server to a failed state further includes: and setting a second timer for the server, and returning to the action of switching the state of the server into detection when the second timer is over.
When the NAT device receives an ICMP destination unreachable message sent by an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further includes:
the NAT equipment determines whether a corresponding session exists according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if so, the NAT equipment switches the state of the server into a detection action; otherwise, keeping the state of the server unchanged;
when the NAT device receives an RST message sent by an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further includes:
the NAT equipment determines whether a corresponding session in a synchronous state exists or not according to the quintuple of the reset message, and if the session exists, the state of the server is switched into a detection action; otherwise, the state of the server is kept unchanged.
After the server is found to provide the TCP service to the outside, before performing a TCP three-way handshake with the server, the method further includes:
judging whether the TCP connection between the equipment and the server exists or not, if so, switching the state of the server to be effective; otherwise, executing the action of TCP three-way handshake with the server.
The method further comprises:
when the NAT equipment receives a service flow first packet, a server with an effective or stable state is selected from the internal server group, and the service flow is shared to the selected server.
The method further comprises:
when the state of the server is found to be switched to detection or delay or failure, selecting a second server as a standby member of the server from the servers with the state of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers;
when receiving a first packet of a service flow, the NAT equipment calculates a server for sharing the service flow according to a preset load balancing algorithm, judges whether the state of the server for sharing the service flow is stable or effective, and directly shares the service flow to the server if the state of the server for sharing the service flow is stable or effective; otherwise, the service flow is shared to the spare member of the server.
A NAT device comprising:
a member status maintenance module: maintaining the state of each member of the internal server group;
a member status detection module: if an ICMP (internet control protocol) destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server into detection, detecting whether the three layers of servers can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state or TCP three-way handshake aiming at the session with the S mark is successful; otherwise, switching the state of the server to failure; or,
if receiving a RST message sent by an intranet device, determining an unreachable server according to the RST message, switching the state of the server to be stable, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if TCP three-time handshake aiming at the session with the S mark is successful; otherwise, the state of the server is switched to failure.
The member status detection module is further configured to,
when an ICMP (internet control protocol) destination unreachable message sent by intranet equipment is received, the state of the server is switched to be invalid, a second timer is set for the server, and when the second timer is overtime, the state of the server is switched to be detected;
when receiving an RST message sent by an intranet device, after the state of the server is switched to be invalid, a second timer is set for the server, and when the second timer is overtime, the state of the server is switched to be a role.
The member status detection module is further configured to,
when NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, after an unreachable server is determined, whether a corresponding session exists or not is determined according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if the session exists, the action of switching the state of the server into detection is executed; otherwise, keeping the state of the server unchanged;
when receiving a RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server into a detection action; otherwise, the state of the server is kept unchanged.
The NAT device further comprises a load sharing module: when receiving the first packet of the service flow, according to the states of each internal server maintained in the member state maintenance module, selecting a server with an effective or stable state from the internal server group, and sharing the service flow to the selected server.
The NAT device further comprises a load sharing module: according to the state of each internal server maintained in the member state maintenance module, when the state of one server is found to be switched to detection or delay or failure, a second server is selected as a standby member of the server from the servers with the states of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
A NAT device comprising:
a member status maintenance module: maintaining the state of each member of the internal server group;
a member status detection module: if an ICMP (internet control protocol) destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server into detection, if the server is found to provide UDP (user datagram protocol) service externally, detecting whether the three layers of servers can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state; otherwise, switching the state of the server to failure; or,
if receiving ICMP purpose unreachable message or RST message sent by an intranet device, determining unreachable server according to the message, switching the state of the server to detection, if finding that the server provides TCP service externally, performing TCP three-way handshake with the server, if successful, switching the state of the server to effective, and if failed, switching the state of the server to invalid.
The member state detection module is further configured to, when receiving an ICMP unreachable message or an RST message sent by an intranet device, switch the state of the server to a failed state, set a second timer for the server, and when the second timer times out, return to the action of switching the state of the server to a detection action.
The member status detection module is further configured to,
when an ICMP destination unreachable message sent by an intranet device is received, after an unreachable server is determined, whether a corresponding session exists is determined according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if the session exists, the action of switching the state of the server into detection is executed; otherwise, keeping the state of the server unchanged;
when receiving a RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server into a detection action; otherwise, the state of the server is kept unchanged.
The member state detection module is further used for judging whether the TCP connection between the equipment and the server exists or not after discovering that the server provides the TCP service to the outside, and if so, switching the state of the server to be effective; otherwise, executing the action of TCP three-way handshake with the server.
The NAT device further comprises a load sharing module: when receiving the first packet of the service flow, according to the states of each internal server maintained in the member state maintenance module, selecting a server with an effective or stable state from the internal server group, and sharing the service flow to the selected server.
The NAT device further comprises a load sharing module: according to the state of each internal server maintained in the member state maintenance module, when the state of one server is found to be switched to detection or delay or failure, a second server is selected as a standby member of the server from the servers with the states of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
Compared with the prior art, the NAT equipment can detect the failure of the members of the internal server group;
in the embodiment of the invention, when the NAT equipment performs load balancing, the service flow is shared to the available server according to the state of the internal server group member, thereby ensuring uninterrupted service.
Drawings
Fig. 1 is a diagram illustrating an example of a network in which an existing internal server group commonly provides a certain service to the outside;
fig. 2 is a flowchart of a method for detecting, by an NAT device, a failure of an internal server group member according to an ICMP destination unreachable message when an internal server group provides a UDP-based service to the outside according to an embodiment of the present invention;
fig. 3 is a flowchart of a method for detecting, by the NAT device, a failure of an internal server group member according to an ICMP destination unreachable message when an internal server group provides a TCP-based service to the outside according to the embodiment of the present invention;
fig. 4 is a flowchart of a method for detecting, by the NAT device, a failure of a group member of the internal server according to the RST message when the internal server group provides a TCP-based service to the outside according to the embodiment of the present invention;
fig. 5 is a flowchart of a method for detecting, by the NAT device, an internal server group member failure through an ICMP destination unreachable message according to the embodiment of the present invention;
fig. 6 is a flowchart of a method for detecting, by the NAT device, a failure of a group member of the internal server according to the RST message according to the embodiment of the present invention;
fig. 7 is a flowchart of a method for load sharing by NAT devices according to an embodiment of the present invention;
fig. 8 is a flowchart of a method for load sharing by NAT devices according to a second embodiment of the present invention;
fig. 9 is a schematic composition diagram of a NAT device according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
In the present invention, an Internet Control Message Protocol (ICMP) unreachable upload switch needs to be opened on each intranet device between the NAT device and the internal server group. After the unreachable internal network equipment sends the ICMP message to the NAT equipment, the NAT equipment can know which server is unreachable according to the ICMP unreachable message.
The services provided by the server are typically UDP-based services or TCP-based services. For UDP-based services, when a request for UDP service fails from a server, the NAT device receives an ICMP destination unreachable message. For the service based on TCP, when the service based on TCP of a server is opened, if the server is not reachable, the NAT equipment receives an ICMP destination unreachable message sent by the intranet equipment; when the TCP-based service of one server is not opened, the NAT device receives a Reset (RST) message sent from the intranet device. Specific examples are given below for each case:
fig. 2 is a flowchart of a method for detecting, by an NAT device, a failure of an internal server group member according to an ICMP destination unreachable message when an internal server group provides a UDP-based service externally, where the method includes the following specific steps, as shown in fig. 2:
step 201: the NAT device establishes a configuration table of each member in the internal server group in itself, the table includes the intranet IP address and the state of each server, and initializes the state of each server to be valid (reacable).
Step 202: the NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, and determines an unreachable server according to the IP header and transmission layer header information of an original data packet carried by the message.
Specifically, the NAT device determines an unreachable server from the protocol numbers, the destination IP address, and the destination port number of the IP header and the transport layer header of the original packet.
After receiving the ICMP purpose unreachable message, the NAT device will go through the NAT process to convert the IP address in the three-layer header between the private network and the public network; meanwhile, if the Application Layer of the message carries an IP address, an Application Layer Gateway (ALG) process is performed to convert the IP address of the Application Layer between the private network and the public network. Therefore, in this step, when receiving the ICMP destination unreachable message and when going through the ALG process, the NAT device determines the unreachable server according to the IP header of the original data packet and the protocol number, destination IP address and destination port number of the transport layer header, and then performs the private-public network conversion on the IP address in the original data packet.
Step 203: the NAT equipment determines whether a corresponding session exists according to a quintuple of an original data packet carried by the ICMP destination unreachable message, if so, the step 205 is executed; otherwise, step 204 is performed.
Step 204: the NAT device keeps the state of the server unchanged, and the process ends.
Step 205: the NAT device switches the state of the server to Probe (Probe).
Step 206: and the NAT equipment finds that the service is based on UDP according to the protocol number in the IP header information of the original data packet carried by the ICMP destination unreachable message, and sends the Ping message to the server.
Step 207: the NAT device judges whether ping is on, if yes, step 208 is executed; otherwise, step 212 is performed.
Here, the ping message is sent to the first server in order to detect whether the server is three-tier reachable.
Step 208: the NAT device switches the state of the server to stale (stale).
Step 209: when the NAT device finds that the traffic flow is shared to the server, an S mark is added to the traffic flow session, the state of the server is switched to delay, and meanwhile, a first timer is set for the server.
Step 210: if the NAT device finds that the first timer is overtime, it determines whether the session with the S flag is switched from the open (open) state to the ready (ready) state, if yes, step 211 is executed; otherwise, step 212 is performed.
When the session is switched from the open state to the ready state, the two-way UDP session is established.
Step 211: the NAT device switches the state of the server to reactable, and returns to step 202.
Step 212: the NAT device switches the state of the server to an unacable, sets a second timer for the server, and returns to step 205 when the second timer times out.
Fig. 3 is a flowchart of a method for detecting, by an NAT device, a failure of an internal server group member according to an ICMP destination unreachable message when an internal server group provides a TCP-based service to the outside, according to an embodiment of the present invention, as shown in fig. 3, the specific steps are as follows:
steps 301 to 305 are the same as steps 201 to 205.
Steps 201 and 301 are initialization steps of the NAT device.
Step 306: the NAT equipment finds that the service is based on TCP according to the protocol number in the IP header information of the original data packet carried by the ICMP destination unreachable message.
Step 307: the NAT device judges whether the TCP connection of the server exists, if yes, step 308 is executed; otherwise, step 309 is performed.
Step 308: and the NAT equipment switches the state of the server into a reacable, and the flow is ended.
Step 309: the NAT device actively performs TCP three-way handshake with the server, judges whether the handshake is successful, and if so, executes step 310; otherwise, step 311 is performed.
Step 310: and the NAT equipment switches the state of the server into reacable, simultaneously sets the state of the TCP connection of the server as 'existing', simultaneously sets a TCP connection timer for the server, and the process is finished.
The purpose of setting the TCP connection timer is to avoid repeatedly establishing and removing TCP connection, and before the TCP connection timer is overtime, if the NAT equipment receives an unreachable message aiming at the server, the message is not considered; after the TCP connection timer expires, if the NAT device receives an ICMP destination unreachable message for the server, the process returns to step 303.
When the TCP connection is torn down, the state of the TCP connection is set to "torn down".
Step 311: the NAT device switches the state of the server to an unacable, sets a third timer for the server, and returns to step 305 when the third timer times out.
Fig. 4 is a flowchart of a method for detecting, by NAT equipment, a failure of a group member of an internal server according to an RST message when the internal server group provides a TCP-based service to the outside, where as shown in fig. 4, the specific steps are as follows:
step 401 is the same as step 201.
Step 402: the NAT equipment receives a RST message sent by intranet equipment, and determines an unreachable server according to the IP header and the transmission layer header information of the message.
Step 403: the NAT equipment searches whether a corresponding session in a Synchronous (SYN) state exists according to the quintuple of the RST message, and if so, executes step 405; otherwise, step 404 is performed.
Step 404: the NAT device keeps the state of the server unchanged, and the process ends.
Step 405: the NAT device switches the state of the server to Probe.
Step 406: the NAT equipment discovers that the service is based on the TCP according to the protocol number in the IP header information of the RST message.
In fig. 2 to 4, different processing flows are given according to different service types provided by the internal server group, and in practical application, the service types provided by the internal server group may not be distinguished.
Fig. 5 is a flowchart of a method for detecting an internal server group member failure by an ICMP destination unreachable message by an NAT device according to an embodiment of the present invention, where as shown in fig. 5, the specific steps are as follows:
Step 506: and the NAT equipment sends a Ping message to the server.
Step 507: the NAT device judges whether ping is on, if yes, step 508 is executed; otherwise, step 512 is performed.
Step 508: the NAT device switches the state of the server to stay.
Step 509: when the NAT device finds that the traffic flow is shared to the server, an S mark is added to the traffic flow session, the state of the server is switched to delay, and meanwhile, a first timer is set for the server.
Step 510: the NAT equipment finds that the first timer is overtime, and judges whether: if the session with the S flag is switched from the open state to the ready state, or the TCP three-way handshake for the session with the S flag is successful, step 511 is executed; otherwise, step 512 is performed.
Step 511: the NAT device switches the state of the server to reactable, and returns to step 502.
Step 512: the NAT device switches the state of the server to an unacable, sets a second timer for the server, and returns to step 508 when the second timer times out.
Fig. 6 is a flowchart of a method for detecting, by the NAT device, a failure of an internal server group member according to the RST message, where as shown in fig. 6, the specific steps are as follows:
steps 601 to 604 are the same as steps 401 to 404.
Step 607: the NAT device finds that the first timer is overtime, determines whether the TCP three-way handshake for the session with the S flag is successful, if so, executes step 608; otherwise, step 609 is performed.
After the embodiments shown in fig. 2 to 4 or the embodiments shown in fig. 5 to 6 detect the states of the members of each server group, the NAT device may only share the service flow to the available members when performing load sharing. The following gives an example of load sharing between two NAT devices:
fig. 7 is a flowchart of a load sharing method performed by a NAT device according to an embodiment of the present invention, and as shown in fig. 7, the specific steps are as follows:
step 701: the state of the first server in a server group discovered by the NAT equipment is switched to probe, delay or unacable.
Step 702: the NAT equipment selects a second server as a standby member of a first server from servers in a state of being stable or reachable, and an IP address of the standby member is placed in a configuration table of the first server; meanwhile, if the NAT device finds that the first server is used as a standby member of other servers, the standby member is selected from the server of the stable or reacable for the other servers.
Table 1 gives an example of a configuration table for the members of an internal server group:
| internal server group member IP address | Status of state | Spare member IP address |
| 10.1.1.2 | reachable | Is free of |
| 10.1.1.3 | unreachable | 10.1.1.2 |
| 10.1.1.4 | stale | Is free of |
| 10.1.1.5 | delay | 10.1.1.4 |
TABLE 1 example of configuration tables for members of an internal Server team
Step 703: and the NAT equipment receives the first packet of the service flow, and calculates the server for sharing the service flow according to a preset load balancing algorithm.
Step 704: the NAT equipment judges whether the state of the server for sharing the service flow is stable or reactable, if yes, step 705 is executed; otherwise, step 706 is performed.
Step 705: the NAT equipment directly shares the service flow to the server, and the flow is finished.
Step 706: the NAT device shares traffic to the standby members of the server.
Fig. 8 is a flowchart of a method for load sharing by a NAT device according to a second embodiment of the present invention, and as shown in fig. 8, the specific steps are as follows:
step 801: the NAT equipment finds that the state of a first server in the internal server group is switched to be stable or reaccable, and then the IP address of the first server is placed into an available server list; and the NAT equipment deletes the IP address of the first server from the available server list when finding that the state of the first server is switched to be probe, delay or unacable.
Step 802: the NAT equipment receives a service flow first packet, and selects one server from an available server list to share the service flow according to a preset load balancing algorithm.
Step 803: the NAT device shares the traffic flow to the selected server.
Fig. 9 is a schematic composition diagram of a NAT device according to an embodiment of the present invention, as shown in fig. 9, the NAT device mainly includes: a member status maintenance module 91 and a member status detection module 92, wherein:
the member status maintenance module 91: and maintaining the state of each member of the internal server group, and initializing the state of each member to be effective.
The member status detection module 92: if an ICMP destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server maintained by the member state maintenance module 91 into detection, detecting whether the three layers of the server are reachable, and if not, switching the state of the server maintained by the member state maintenance module 91 into failure; if yes, the state of the server maintained by the member state maintenance module 91 is switched to be a stable state, when a service flow is shared to the server, an S flag is added to a session corresponding to the service flow, the state of the server maintained by the member state maintenance module 91 is switched to be a delay, a first timer is set for the server, and before the first timer is overtime, if the session with the S flag is switched from an open state to a ready state, or TCP three-way handshake for the session with the S flag is successful, the state of the server maintained by the member state maintenance module 91 is switched to be effective; otherwise, the state of the server maintained by the member state maintenance module 91 is switched to failure. Or, if an RST message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server maintained by the member state maintenance module 91 to stay, when a service flow is shared to the server, adding an S flag to a session corresponding to the service flow, switching the state of the server maintained by the member state maintenance module 91 to delay, setting a first timer for the server, and if TCP three-way handshake for the session with the S flag succeeds before the first timer expires, switching the state of the server maintained by the member state maintenance module 91 to be valid; otherwise, the state of the server maintained by the member state maintenance module 91 is switched to failure.
The member state detection module 92 is further configured to, when receiving an ICMP unreachable message sent by an intranet device, set a second timer for the server after switching the state of the server maintained by the member state maintenance module 91 to invalid, and when the second timer times out, return to the action of switching the state of the server maintained by the member state maintenance module 91 to detection; when receiving an RST message sent by an intranet device, switching the state of the server maintained by the member state maintenance module 91 to failure, setting a second timer for the server, and when the second timer times out, returning to the action of switching the state of the server maintained by the member state maintenance module 91 to stay.
The member state detection module 92 is further configured to, after determining an unreachable server when the NAT device receives an ICMP destination unreachable message sent by an intranet device, determine whether a corresponding session exists according to a quintuple of an original data packet carried in the ICMP destination unreachable message, and if the session exists, execute an action of switching a state of the server maintained by the member state maintenance module 91 to a detection action; otherwise, keeping the state of the server unchanged; when receiving an RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server maintained by the member state maintenance module 91 into a detection action; otherwise, the state of the server is kept unchanged.
The NAT device further comprises a load sharing module: when receiving the first packet of the service flow, the method selects a server with a valid or stable state from the internal server group according to the states of the internal servers maintained in the member state maintenance module 91, and shares the service flow to the selected server.
Or, the NAT device further includes a load sharing module: the server state maintenance module 91 is used for selecting a second server as a standby member of the server from the servers with the state of stay or valid according to the state of each internal server maintained in the member state maintenance module when the state of one server is found to be switched to detection or delay or failure; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
The following provides a composition of the NAT device provided in the second embodiment of the present invention, where the NAT device mainly includes: member state maintenance module and member state detection module, wherein:
a member status maintenance module: the status of the members of the internal server group is maintained.
A member status detection module: if an ICMP (internet control protocol) destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server maintained by the member state maintenance module into detection, if the server is found to provide UDP (user datagram protocol) service externally, detecting whether three layers of the server are reachable, and if not, switching the state of the server maintained by the member state maintenance module into failure; if yes, the state of the server maintained by the member state maintenance module is switched to be a stable state, when a service flow is shared on the server, an S mark is added to a corresponding session of the service flow, the state of the server maintained by the member state maintenance module is switched to be a delay, a first timer is set for the server, and before the first timer is overtime, if the session with the S mark is switched from an open state to a ready state, the state of the server maintained by the member state maintenance module is switched to be effective; otherwise, the state of the server maintained by the member state maintenance module is switched to failure. Or if receiving an ICMP unreachable message or an RST message sent by an intranet device, determining an unreachable server according to the message, switching the state of the server maintained by the member state maintenance module to detection, if finding that the server provides TCP service externally, performing TCP three-way handshake with the server, if successful, switching the state of the server maintained by the member state maintenance module to valid, and if failed, switching the state of the server maintained by the member state maintenance module to invalid.
The member state detection module is further configured to, when receiving an ICMP unreachable message or an RST message sent by an intranet device, switch the state of the server maintained by the member state maintenance module to invalid, set a second timer for the server, and when the second timer times out, return to the action of switching the state of the server maintained by the member state maintenance module to detection.
The member state detection module is further used for determining whether a corresponding session exists according to a quintuple of an original data packet carried by an ICMP destination unreachable message after the unreachable server is determined when the ICMP destination unreachable message sent by an intranet device is received, and if the session exists, executing an action of switching the state of the server maintained by the member state maintenance module into detection; otherwise, keeping the state of the server unchanged; when receiving a RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server maintained by a member state maintenance module into detection; otherwise, the state of the server is kept unchanged.
The member state detection module is further used for judging whether the TCP connection between the equipment and the server exists or not after discovering that the server provides the TCP service to the outside, and if so, switching the state of the server maintained by the member state maintenance module to be effective; otherwise, executing the action of TCP three-way handshake with the server.
The NAT device further comprises a load sharing module: and the server is used for selecting a server with an effective or stable state from the internal server group according to the states of the internal servers maintained in the member state maintenance module when receiving the first packet of the service flow, and sharing the service flow to the selected server.
Or, the NAT device further includes a load sharing module: the server state maintenance module is used for maintaining the states of the internal servers in the server state maintenance module, and when the state of one server is found to be switched to detection or delay or failure, a second server is selected as a standby member of the server from the servers with the states of stay or valid; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (22)
1. A method for detecting failures of members of an internal server group, the method comprising:
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, determining an unreachable server according to the message, switching the state of the server into detection, detecting whether the three layers of the server can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state or TCP three-way handshake aiming at the session with the S mark is successful; otherwise, switching the state of the server to failure;
if NAT equipment receives RST messages sent by intranet equipment, an unreachable server is determined according to the RST messages, the state of the server is switched to be stable, when a service flow is shared on the server, an S mark is added to a session corresponding to the service flow, the state of the server is switched to be delay, a first timer is set for the server, and before the first timer is overtime, if TCP three-time handshake aiming at the session with the S mark is successful, the state of the server is switched to be effective; otherwise, the state of the server is switched to failure.
2. The method according to claim 1, wherein when the NAT device receives an ICMP unreachable message sent from an intranet device, the switching the state of the server to the state after the failure further comprises: setting a second timer for the server, and returning to the action of switching the state of the server into detection when the second timer is overtime;
when the NAT device receives an RST message sent by an intranet device, the switching the state of the server to be invalid further includes: and setting a second timer for the server, and returning to the action of switching the state of the server to the stable when the second timer times out.
3. The method according to claim 1, wherein when the NAT device receives an ICMP unreachable message sent from an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further comprises:
the NAT equipment determines whether a corresponding session exists according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if so, the NAT equipment switches the state of the server into a detection action; otherwise, keeping the state of the server unchanged;
when the NAT device receives an RST message sent by an intranet device, after determining the unreachable server, before switching the state of the server to a standby, the method further includes:
the NAT equipment determines whether a corresponding session in a synchronous state exists or not according to the quintuple of the reset message, and if the session exists, the state of the server is switched into a detection action; otherwise, the state of the server is kept unchanged.
4. The method of any of claims 1 to 4, further comprising:
when the NAT equipment receives a service flow first packet, a server with an effective or stable state is selected from the internal server group, and the service flow is shared to the selected server.
5. The method of any of claims 1 to 4, further comprising:
when the state of the server is found to be switched to detection or delay or failure, selecting a second server as a standby member of the server from the servers with the state of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers;
when receiving a first packet of a service flow, the NAT equipment calculates a server for sharing the service flow according to a preset load balancing algorithm, judges whether the state of the server for sharing the service flow is stable or effective, and directly shares the service flow to the server if the state of the server for sharing the service flow is stable or effective; otherwise, the service flow is shared to the spare member of the server.
6. A method for detecting failures of members of an internal server group, the method comprising:
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, determining an unreachable server according to the message, and switching the state of the server into detection, if the server is found to provide UDP (user datagram protocol) service to the outside, detecting whether three layers of the server are reachable, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state; otherwise, switching the state of the server to failure;
if the NAT equipment receives an ICMP (internet control protocol) destination unreachable message or an RST (quick response request) message sent by intranet equipment, determining an unreachable server according to the message, switching the state of the server to detection, if finding that the server provides TCP (transmission control protocol) service to the outside, performing TCP three-way handshake with the server, if successful, switching the state of the server to effective, and if failed, switching the state of the server to invalid.
7. The method according to claim 6, wherein when the NAT device receives an ICMP unreachable message or an RST message sent from an intranet device, the switching the state of the server to a failed state further comprises: and setting a second timer for the server, and returning to the action of switching the state of the server into detection when the second timer is over.
8. The method according to claim 6, wherein when the NAT device receives an ICMP unreachable message sent from an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further comprises:
the NAT equipment determines whether a corresponding session exists according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if so, the NAT equipment switches the state of the server into a detection action; otherwise, keeping the state of the server unchanged;
when the NAT device receives an RST message sent by an intranet device, after determining the unreachable server, switching the state of the server to a state before detecting further includes:
the NAT equipment determines whether a corresponding session in a synchronous state exists or not according to the quintuple of the reset message, and if the session exists, the state of the server is switched into a detection action; otherwise, the state of the server is kept unchanged.
9. The method according to claim 6, wherein after discovering that the server provides the TCP service externally, before performing a TCP three-way handshake with the server, the method further comprises:
judging whether the TCP connection between the equipment and the server exists or not, if so, switching the state of the server to be effective; otherwise, executing the action of TCP three-way handshake with the server.
10. The method of any of claims 6 to 9, further comprising:
when the NAT equipment receives a service flow first packet, a server with an effective or stable state is selected from the internal server group, and the service flow is shared to the selected server.
11. The method of any of claims 6 to 9, further comprising:
when the state of the server is found to be switched to detection or delay or failure, selecting a second server as a standby member of the server from the servers with the state of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers;
when receiving a first packet of a service flow, the NAT equipment calculates a server for sharing the service flow according to a preset load balancing algorithm, judges whether the state of the server for sharing the service flow is stable or effective, and directly shares the service flow to the server if the state of the server for sharing the service flow is stable or effective; otherwise, the service flow is shared to the spare member of the server.
12. A NAT device, comprising:
a member status maintenance module: maintaining the state of each member of the internal server group;
a member status detection module: if an ICMP (internet control protocol) destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server into detection, detecting whether the three layers of servers can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state or TCP three-way handshake aiming at the session with the S mark is successful; otherwise, switching the state of the server to failure; or,
if receiving a RST message sent by an intranet device, determining an unreachable server according to the RST message, switching the state of the server to be stable, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if TCP three-time handshake aiming at the session with the S mark is successful; otherwise, the state of the server is switched to failure.
13. The NAT device of claim 12, wherein the member status detection module is further configured to,
when an ICMP (internet control protocol) destination unreachable message sent by intranet equipment is received, the state of the server is switched to be invalid, a second timer is set for the server, and when the second timer is overtime, the state of the server is switched to be detected;
when receiving an RST message sent by an intranet device, after the state of the server is switched to be invalid, a second timer is set for the server, and when the second timer is overtime, the state of the server is switched to be a role.
14. The NAT device of claim 12, wherein the member status detection module is further configured to,
when NAT equipment receives an ICMP (internet control protocol) destination unreachable message sent by intranet equipment, after an unreachable server is determined, whether a corresponding session exists or not is determined according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if the session exists, the action of switching the state of the server into detection is executed; otherwise, keeping the state of the server unchanged;
when receiving a RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server into a detection action; otherwise, the state of the server is kept unchanged.
15. The NAT device of any of claims 12-14, wherein the NAT device further comprises a load sharing module: when receiving the first packet of the service flow, according to the states of each internal server maintained in the member state maintenance module, selecting a server with an effective or stable state from the internal server group, and sharing the service flow to the selected server.
16. The NAT device of any of claims 12-14, wherein the NAT device further comprises a load sharing module: according to the state of each internal server maintained in the member state maintenance module, when the state of one server is found to be switched to detection or delay or failure, a second server is selected as a standby member of the server from the servers with the states of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
17. A NAT device, comprising:
a member status maintenance module: maintaining the state of each member of the internal server group;
a member status detection module: if an ICMP (internet control protocol) destination unreachable message sent by an intranet device is received, determining an unreachable server according to the message, switching the state of the server into detection, if the server is found to provide UDP (user datagram protocol) service externally, detecting whether the three layers of servers can be reached, and if not, switching the state of the server into failure; if yes, switching the state of the server to be a stay, when a service flow is shared on the server, adding an S mark to a session corresponding to the service flow, switching the state of the server to be a delay, setting a first timer for the server, and before the first timer is overtime, switching the state of the server to be effective if the session with the S mark is switched from an open state to a ready state; otherwise, switching the state of the server to failure; or,
if receiving ICMP purpose unreachable message or RST message sent by an intranet device, determining unreachable server according to the message, switching the state of the server to detection, if finding that the server provides TCP service externally, performing TCP three-way handshake with the server, if successful, switching the state of the server to effective, and if failed, switching the state of the server to invalid.
18. The NAT device of claim 17, wherein the member status detection module is further configured to, when receiving an ICMP unreachable message or an RST message sent by an intranet device, switch the state of the server to a failed state, set a second timer for the server, and when the second timer times out, return to the action of switching the state of the server to a detection action.
19. The NAT device of claim 17, wherein the member status detection module is further configured to,
when an ICMP destination unreachable message sent by an intranet device is received, after an unreachable server is determined, whether a corresponding session exists is determined according to a quintuple of an original data packet carried by the ICMP destination unreachable message, and if the session exists, the action of switching the state of the server into detection is executed; otherwise, keeping the state of the server unchanged;
when receiving a RST message sent by an intranet device, after determining an unreachable server, determining whether a corresponding session in a synchronous state exists according to a quintuple of a reset message, and if so, executing an action of switching the state of the server into a detection action; otherwise, the state of the server is kept unchanged.
20. The NAT device of claim 17, wherein the member state detection module is further configured to, after discovering that the server provides the TCP service to the outside, determine whether a TCP connection between the device and the server exists, and if so, switch the state of the server to be valid; otherwise, executing the action of TCP three-way handshake with the server.
21. The NAT device of any one of claims 17-20, wherein the NAT device further comprises a load sharing module: when receiving the first packet of the service flow, according to the states of each internal server maintained in the member state maintenance module, selecting a server with an effective or stable state from the internal server group, and sharing the service flow to the selected server.
22. The NAT device of any one of claims 17-20, wherein the NAT device further comprises a load sharing module: according to the state of each internal server maintained in the member state maintenance module, when the state of one server is found to be switched to detection or delay or failure, a second server is selected as a standby member of the server from the servers with the states of stay or effective; if the server is found to be used as a standby member of other servers, selecting a standby member from the server of the stable or reachable for the other servers; when a first packet of a service flow is received, calculating a server for sharing the service flow according to a preset load balancing algorithm, judging whether the state of the server for sharing the service flow is stable or effective, and if so, directly sharing the service flow to the server; otherwise, the service flow is shared to the spare member of the server.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110289707.5A CN102299831B (en) | 2011-09-27 | 2011-09-27 | Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110289707.5A CN102299831B (en) | 2011-09-27 | 2011-09-27 | Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102299831A true CN102299831A (en) | 2011-12-28 |
| CN102299831B CN102299831B (en) | 2014-02-05 |
Family
ID=45360018
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110289707.5A Active CN102299831B (en) | 2011-09-27 | 2011-09-27 | Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102299831B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106067887A (en) * | 2016-08-09 | 2016-11-02 | 上海斐讯数据通信技术有限公司 | A kind of website attachment means based on network switching and method, a kind of router |
| CN112751728A (en) * | 2020-12-29 | 2021-05-04 | 杭州迪普科技股份有限公司 | Link health state monitoring method and device |
| CN113645256A (en) * | 2021-10-13 | 2021-11-12 | 成都数默科技有限公司 | Aggregation method without reducing TCP session data value density |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1909507A (en) * | 2006-07-04 | 2007-02-07 | 华为技术有限公司 | Method and system for message transfer |
| US7313735B1 (en) * | 2004-04-30 | 2007-12-25 | Sun Microsystems, Inc. | In-line server health checking |
| CN101640620A (en) * | 2009-09-01 | 2010-02-03 | 杭州华三通信技术有限公司 | Method and device for health detection for equalized equipment |
| CN102195828A (en) * | 2010-03-16 | 2011-09-21 | 华为技术有限公司 | Detection method for server port state and detector |
-
2011
- 2011-09-27 CN CN201110289707.5A patent/CN102299831B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7313735B1 (en) * | 2004-04-30 | 2007-12-25 | Sun Microsystems, Inc. | In-line server health checking |
| CN1909507A (en) * | 2006-07-04 | 2007-02-07 | 华为技术有限公司 | Method and system for message transfer |
| CN101640620A (en) * | 2009-09-01 | 2010-02-03 | 杭州华三通信技术有限公司 | Method and device for health detection for equalized equipment |
| CN102195828A (en) * | 2010-03-16 | 2011-09-21 | 华为技术有限公司 | Detection method for server port state and detector |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106067887A (en) * | 2016-08-09 | 2016-11-02 | 上海斐讯数据通信技术有限公司 | A kind of website attachment means based on network switching and method, a kind of router |
| CN106067887B (en) * | 2016-08-09 | 2020-01-07 | 上海斐讯数据通信技术有限公司 | Website connecting device and method based on network switching and router |
| CN112751728A (en) * | 2020-12-29 | 2021-05-04 | 杭州迪普科技股份有限公司 | Link health state monitoring method and device |
| CN113645256A (en) * | 2021-10-13 | 2021-11-12 | 成都数默科技有限公司 | Aggregation method without reducing TCP session data value density |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102299831B (en) | 2014-02-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101678711B1 (en) | Load balancing across layer-2 domains | |
| US10742488B2 (en) | Detecting link faults in network paths that include link aggregation groups (LAGs) | |
| KR101467726B1 (en) | Concept for providing information on a data packet association and for forwarding a data packet | |
| US8812664B2 (en) | Controlling an apparatus | |
| US9515920B2 (en) | Name-based neighbor discovery and multi-hop service discovery in information-centric networks | |
| JP5967601B2 (en) | Method of detecting link failure and switching session to normal link in network multihoming environment based on ID / locator separation | |
| EP2399370B1 (en) | Maximum transmission unit, MTU, size discovery method for data-link layers | |
| CA2485175A1 (en) | Methods and apparatus for mobile ip dynamic home agent allocation | |
| Kim et al. | SEATTLE: A scalable ethernet architecture for large enterprises | |
| JP2013526107A (en) | Data message processing method, system, and access service node | |
| CN101888338B (en) | information forwarding method and gateway | |
| CN102299831A (en) | Method for detecting invalidation of group members of internal server and network address translation (NAT) equipment | |
| Ishiyama et al. | An analysis of mobility handling in LIN6 | |
| Barré et al. | Implementation and evaluation of the Shim6 protocol in the Linux kernel | |
| US10735252B2 (en) | Outside router fault detection | |
| Sun et al. | Mobility support in multi-path tcp | |
| Li et al. | Artemis: A Latency-Oriented Naming and Routing System | |
| Dhraief et al. | An M2M gateway-centric architecture for autonomic healing and optimising of machine-to-machine overlay networks | |
| Dhraief et al. | A service-oriented framework for mobility and multihoming support | |
| CN106793061B (en) | A kind of subnet based on LISP fast moves switching method | |
| CN102984182B (en) | A kind of P2P network mobility management methods and system | |
| US20090274057A1 (en) | Systems, Methods and Software for Identifying a Preferred Egress Gateway in a Bypass Network for Accessing a Content Server in Another Network | |
| Dhraief et al. | Mobility impact on session survivability under the shim6 protocol and enhancement of its rehoming procedure | |
| Asara | Client infrastructure design and implementation of a client-server Internet topology mapping system for smartphones | |
| Detal | Evaluating and improving the deployability of Multipath TCP. |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 310052 Binjiang District Changhe Road, Zhejiang, China, No. 466, No. Patentee after: Xinhua three Technology Co., Ltd. Address before: 310053 Hangzhou hi tech Industrial Development Zone, Zhejiang province science and Technology Industrial Park, No. 310 and No. six road, HUAWEI, Hangzhou production base Patentee before: Huasan Communication Technology Co., Ltd. |