CN101977156B - Method, device and routing equipment for learning maximum transmission unit - Google Patents
Method, device and routing equipment for learning maximum transmission unit Download PDFInfo
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Abstract
The invention discloses a method, a device and routing equipment for learning the maximum transmission unit. The method comprises the following steps of: receiving border gateway protocol (BGP) routing information reaching an IPv6 network and informed by an upstream BGP neighbor in an IPv6 message transmission tunnel, wherein the BGP routing information carries a first maximum transmission unit (MTU) reaching a route of the IPv6 network and determined by the upstream BGP neighbor; detecting a second MTU corresponding to the next hop of the BGP route carried by the BGP routing information; comparing the size of the first MTU and the second MTU, taking the small value as the determined third MTU reaching the BGP route of the IPv6 network, and saving the small value; and when a downstream BGP neighbor is present in the tunnel is determined, carrying the third MTU in the BGP routing information reaching the IPv6 network and informing the downstream BGP neighbor. The invention solves the problem of low message forwarding efficiency caused by transmission blockage and segmentation for multiple times of IPv6 messages in the transmission process.
Description
Technical field
The present invention relates to the computer network communication technology field, relate in particular to learning method, device and the routing device of a kind of MTU MTU.
Background technology
Existing internet protocol version 6 (IPv6) network is as next generation network, and is not universal fully as yet at present, still is dispersed among internet protocol version 4 (IPv4) network as island network.Can realize interconnecting through the IPv4 network in order to realize these IPv6 networks; The general tunneling technique that adopts; As utilize internet protocol version 4-multiprotocol label switching (IPv4-MPLS) network that IPv6 message transmissions tunnel is provided; Thereby realize interconnecting of isolated IPv6 site network, the Internet engineering duty group (The Internet EngineeringTask Force, the corresponding standard that IETF) has been this solution formulation; Be called IPv6 operator edge (IPv6Provider Edge, 6PE) scheme.
Shown in Figure 1 is to adopt the 6PE scheme to realize an object lesson of the IPv6 network interconnection; This example be single autonomous territory (Autonomous System, the interconnecting of the IPv6 network in AS) is in Fig. 1; Routing device 6PE-1,6PE-2, the router (Provider of operator; Be called for short P) formed entire I Pv4MPLS network with 6PE-3, wherein P equipment is IPv4 list protocol stack routing device in the network, other each equipment are all supported IPv6, IPv4 dual stack.(Internal Border Gateway Protocol, IBGP) the IPv6 routing iinformation of distribution tape label are example with 6PE-1 announcement IPv6 network address S1 through Internal BGP between 6PE-1,6PE-2, the 6PE-3; 6PE-1 through the multi-protocols Internal BGP (Multiprotocol-IBGP, MP-IBGP) agreement is to the IPv6 route of 6PE-3 announcement tape label, the network address is S1; Corresponding label value is L1; 6PE-3 is after receiving this label route, and with interpolation IPv6 route, outgoing label is L1; Next is jumped and is 6PE-1, has promptly had the IPv6 route of arrival S1 in the IPv6S3 network like this.Same principle can realize that the IPv6 route interconnects between S1, S2, the S3.
The IPv6 message is described below how in the MPLS transmission through network; 6PE-3 is when receiving that destination address is the IPv6 message of S1; To search local IPv6 routing table, confirm that next is jumped is 6PE-1, and outgoing label be L1 (this message is distributed by 6PE-1); 6PE-3 is that label L1 is gone up in this IPv6 message encapsulation afterwards, searches the outlet that next jumps 6PE-1 simultaneously.Transmit according to MPLS and to confirm to reach 6PE-1; Need to insert label T1 (for the MPLS tunnel label of 6PE-3 to 6PE-1), and be forwarded to P, original IPv6 message will comprise double-layer label this moment; Vpn label is IPv6 routing tag (L1), and outer layer label is MPLS tunnel label (T1).P is after receiving this message, and it is indifferent to what encapsulate in the message is IPv4 data or IPv6 data, confirms that according to outer layer label T1 this message will be forwarded to 6PE-1, and switch label T1 is T2, and this moment, the label stack of message became T2/L1.6PE-1 will eject label T2 after receiving this message, confirm to be forwarded to the correct network segment according to IPv6 label L1 simultaneously.
Above-mentioned IP v6 message is run into two problems easily in transmission; On the one hand; Equipment P in the IPv4 network will carry out MTU (Maximum Transmission Unit when E-Packeting; MTU) inspection checks that promptly whether this message length surpasses the MTU of outgoing interface, if when the length of the message of current reception surpasses the MTU of its outgoing interface, P can only abandon this message owing to can't discern the IPv6 message; On the other hand; Even the length of message does not surpass the MTU of P outgoing interface, successfully be forwarded to 6PE-1 by P, 6PE-1 confirms to be forwarded to certain outgoing interface according to the label L1 and the IPv6 route of this message; When if the length of current message surpasses the MTU of 6PE-1 outgoing interface; 6PE-1 will carry out burst once more for this IPv6 message, cause the IPv6 message in that transmission course has been reduced the message forward efficiency by burst repeatedly through the tunnel like this.
Shown in Figure 2 is to adopt the 6PE scheme to realize that the another one object lesson of the IPv6 network interconnection, this example are the interconnecting of IPv6 network of striding a plurality of autonomous territories, and AS1 is by 6PE-1, P and Autonomous System Boundary Router, AS Boundary Router (Autonomous System Border Router among Fig. 2; ASBR) 1 forms; AS2 forms (can also comprise some P equipment between ASBR2 and the 6PE-2, in Fig. 2, not illustrate) by ASBR2 and 6PE-2, and IPv6S1 connects autonomous territory AS1 through 6PE-1; IPv6S2 connects autonomous territory AS2; Set up MP-IBGP between 6PE-1 and the ASBR1 and connect, 6PE-1 gives ASBR1 with the IPv6 advertising of route of tape label, sets up multiprotocol bgp agreement (Multiprotocol Extensions BGP between ASBR1 and the ASBR2; MP-EBGP) connect; ASBR1 announces the tape label IPv6 route of 6PE-1 to ASBR-2 through MP-EBGP, and ASBR2 sets up MP-IBGP with 6PE-2 and is connected, and ASBR2 announces the tape label IPv6 route of ASBR1 announcement to 6PE-2 through MP-IBGP again; 6PE-2 can learn the tape label Ipv6 route of 6PE-1 like this, and S2 and S1 learn IPv6 route separately each other.
The IPv6 message forwarding then realizes through setting up three MPLS tunnels; T3 (tunnel between 6PE-1 and the ASBR1), T2 (tunnel between ASBR1 and the ASBR2) and T1 (tunnel between ASBR2 and the 6PE-2) in showing like Fig. 2; 6PE-2 will be forwarded to ASBR2 through tunnel T1 with message earlier after receiving the IPv6 message that arrives S1, ASBR2 is forwarded to ASBR1 through tunnel T2 again; ASBR1 then is forwarded to 6PE-1 through MPLS tunnel T3 with message, thereby realizes the IPv6 message forwarding.Because 6PE-2 need not know how to arrive ASBR1 and 6PE-1, it only need be forwarded to ASBR2 with message, and remaining forwarding operation then has ASBR2 to carry out; When message is forwarded to ASBR2; ASBR2 can carry out mtu checking, if transmit after the length of message above the MTU of its outgoing interface, need be carried out burst so; Similarly; ASBR2 and 6PE-2 need carry out the inspection of MTU too at repeating process, possibly cause the IPv6 message in that transmission course has been reduced the message forward efficiency by burst repeatedly through the tunnel like this.In addition; Message is via P device forwards to the boundary routing device among AS1 and the AS2 time; Also might make the transmission course of IPv6 message be obstructed and cause to realize intercommunication between the IPv6 network because its length make P equipment directly abandon this message greater than the MTU of P equipment outgoing interface.
Summary of the invention
The embodiment of the invention provides learning method, device and the routing device of a kind of MTU MTU, in transmission course, causes transmit the message forward efficiency low problem of being obstructed and by repeatedly burst being caused because length scale surpasses routing device outgoing interface MTU in order to solve in existing 6PE technology IPv6 message.
The learning method of a kind of MTU that the embodiment of the invention provides comprises:
Routing device for each the running boundary gateway protocol BGP in the IPv6 message transmissions tunnel that forms in the IPv4 network is carried out following operation:
Receive the bgp routing information of the arrival IPv6 network of IPv6 message transmissions tunnel middle and upper reaches Border Gateway Protocol (BGP) neighbor advertisement; Carry a MTU of the route of the arrival IPv6 network that said upper reaches bgp neighbor determines in the said bgp routing information;
The 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that the said bgp routing information that receives is carried surveys;
The size of a more said MTU and the 2nd MTU that detects is with three MTU and the preservation of the smaller value among both as the BGP route of the arrival IPv6 network of determining;
Confirm whether also there is the downstream bgp neighbor in the said tunnel,, be carried in the bgp routing information that arrives this IPv6 network said the 3rd MTU and announcement to said downstream bgp neighbor if exist; If do not exist, then finish the learning process of MTU.
The learning device of a kind of MTU that the embodiment of the invention provides comprises:
The bgp routing information receiving element is used to receive the bgp routing information of the arrival IPv6 network of IPv6 message transmissions tunnel middle and upper reaches Border Gateway Protocol (BGP) neighbor advertisement; Carry a MTU of the route of the arrival IPv6 network that said upper reaches bgp neighbor determines in the said bgp routing information;
The MTU probe unit, the 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that is used for the said bgp routing information that receives is carried surveys;
Comparing unit is used for the size with the 2nd MTU that detects with a more said MTU, with three MTU and the preservation of smaller value among both as the BGP route of the arrival IPv6 network of determining;
The advertising of route unit is used for confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 network said the 3rd MTU and announcement to said downstream bgp neighbor.
The routing device that the embodiment of the invention provides comprises the learning device of the above-mentioned MTU that the embodiment of the invention provides.
The beneficial effect of the embodiment of the invention comprises:
The learning method of the MTU that the embodiment of the invention provides, device and routing device; For the routing device of each the operation BGP in the IPv6 message transmissions tunnel that forms in the IPv4 network, carry out following operation promptly: the bgp routing information that receives the arrival IPv6 network of upper reaches bgp neighbor announcement; This bgp routing information carries a MTU of the route of the arrival IPv6 network that this upper reaches bgp neighbor determines; The 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that the bgp routing information that receives is carried surveys; The size of the 2nd MTU that compares a MTU and detect is with three MTU and the preservation of smaller value among both as the BGP route of the arrival IPv6 network of determining; If also there is the downstream bgp neighbor; Then the 3rd MTU is carried at and also announces to downstream bgp neighbor in the bgp routing information that arrives this IPv6 network, the routing device of each the operation BGP in this tunnel has all learnt to arrive the corresponding MTU of BGP route of this IPv6 network.The embodiment of the invention is passed through the value that the BGP route is transmitted MTU between the operator edge device of supporting bgp protocol and autonomous system boundary route; The operator edge device that makes the terminal point in tunnel of transmission IPv6 message promptly connect another IPv6 network can calculate the minimum value of each MTU that jumps in the route that arrives purpose IPv6 network; And whether it need be carried out the foundation of burst as sending the IPv6 message; Through after the said process; When the terminal point in this tunnel is received the IPv6 message that mails to this IPv6 network; The size of the size of this message and the MTU that self preserves is compared, and whether decision needs burst, if carry out burst; The length of the message behind the burst is to arrive the minimum value of respectively jumping MTU in the route of this IPv6 network; Therefore, for especially striding the application scenarios that interconnects that the IPv6 networks are realized in the autonomous territory of a plurality of IPv4, no matter how many intermediate equipments (for example P equipment) or edge device need be crossed in the tunnel of IPv4 transmission through network IPv6 message through the application scenarios that interconnects of IPv4 network realization IPv6 network; Any intermediate equipment or edge device; Can not exceed because of the size of IPv6 message length this routing device outgoing interface MTU size and abandon this IPv6 message, thereby the situation of having avoided the transmission of the IPv6 message that existing 6PE technology occurs to be obstructed, and after the terminal point in this tunnel carries out Fragmentation to the IPv6 message of receiving; Other routing devices can not carried out the Fragmentation of message more yet in this tunnel, have improved IPv6 message forward efficiency in the tunnel.
Description of drawings
Fig. 1 is that the 6PE scheme realizes that the network of the IPv6 network interconnection connects one of sketch map in the prior art;
Fig. 2 is that the 6PE scheme realizes that the network of the IPv6 network interconnection connects two of sketch map in the prior art;
The flow chart of the learning method of the MTU that Fig. 3 provides for the embodiment of the invention;
Fig. 4 is the form sketch map of self-defined group attribute;
Fig. 5 connects sketch map for the network of first instantiation that the embodiment of the invention provides;
The structural representation of the learning device of the MTU that Fig. 6 provides for the embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing, learning method, device and the routing device of a kind of MTU (MTU) that the embodiment of the invention is provided are at length explained.
The MTU learning method that the embodiment of the invention provides, as shown in Figure 3, comprise the steps:
The bgp routing information of the arrival IPv6 network of S301, the tunnel middle and upper reaches bgp neighbor announcement of reception IPv6 message transmissions; Carry a MTU of the route of the arrival IPv6 network that this upper reaches bgp neighbor determines in this bgp routing information;
The 2nd MTU of the BGP route next jump of S302, this IPv6 network of arrival that the bgp routing information that receives is carried surveys;
The size of S303, a more said MTU and the 2nd MTU that detects, with smaller value among both as the 3rd MTU of the BGP route of the arrival IPv6 network of determining and preserve;
S304, confirm whether also there is the downstream bgp neighbor in the IPv6 message transmissions tunnel; If exist, carry out following step S305; If there is not process ends;
S305, be carried at the 3rd MTU in the bgp routing information that arrives this IPv6 network and announcement to downstream bgp neighbor.
Among the above-mentioned steps S301, IPv6 message transmissions tunnel refers to the IPv6 message transmissions passage that the IPv4-MPLS network that connects two IPv6 networks provides.
Among above-mentioned steps S301 and the step S305; In the bgp routing information that arrives the IPv6 network, carry a MTU or carry the 3rd MTU; Can realize through following manner: the extended community attribute in the self-defined bgp routing information is encapsulated in the value of a MTU or the 3rd MTU in the Value field of said extended community attribute.
Extended community attribute (Extended Communities Attribute) is a type in the routing property in the bgp routing information; Its form is as shown in Figure 4; Self-defined group attribute; Can self-defined type field (type of extended community attribute) wherein be MTU, the value of a MTU or the 3rd MTU is encapsulated in the Value field of self-defining extended community attribute.
Preferably; In embodiments of the present invention; Also need preserve simultaneously the MTU that obtains in this MTU learning process and the 2nd MTU also with the bgp routing information that arrives the IPv6 network; So that when follow-up MTU changes, can in time upgrade the 3rd MTU that preserves according to a MTU who preserves and the 2nd MTU.
Below in conjunction with two concrete instances, the MTU learning method that the embodiment of the invention provides is at length explained.
First instance:
This instance adopts the network topology of the IPv6 network interconnection in the autonomous territory of list shown in Figure 5; Operator edge device R1 links to each other with the IPv6S1 network; Operator edge device R2 links to each other with the IPv6S2 network, and R1 and R2 belong to the IPv4-MPLS network simultaneously, in order to realize that the IPv6 message of IPv6S2 network is sent to the IPv6S1 network; Need, message carry out the routing device R1 of bgp protocol and R2 carries out MTU study respectively according to following flow process step before sending:
The bgp neighbor at step 1, R1 its upper reaches in IPv6 message transmissions tunnel is the bgp routing information that R2 announcement arrives the IPv6S1 network, in the BGP route of announcement, carries the MTU1 of the route of the arrival IPv6S1 network that R1 determines;
In this step 1, because R1 is the operator edge device that directly links to each other with the IPv6S1 network, the value of MTU1, the value of the MTU that R1 can be through obtaining outgoing interface corresponding with the route of arrival IPv6S1 network among the R1 obtains MTU1.
R1 is carried at the value of MTU1 in the self-defining extended community attribute, and concrete grammar is referring to the explanation of abovementioned steps S301.
R2 extracts the IP address of next jumping of this BGP route from the bgp routing information that receives; Next jumping of BGP route is a kind of of routing property in the bgp routing information, is used to indicate the routing device (being R1) that the network (IPv6S1 network) that arrives this route prefix correspondence need be forwarded to message BGP next hop.
According to the IP address of next jumping (R1) of this BGP route, R2 can survey this automatically, and next jumps corresponding MTU value.Specifically can adopt existing automatic detection method; For example through sending Internet Control Message Protocol (Internet Control Message Protocol; ICMP) message is found MTU2; If also be connected with some P equipment or other routing devices on the path in this transmission tunnel between R1 and the R2, survey the process of MTU2, promptly confirm to arrive through some P equipment or other routing devices the minimum value of the MTU value of respectively jumping the path of R1 from R2.Concrete detection method belongs to prior art, repeats no more at this.
MTU3 can be stored in the routing table with the BGP route that arrives the IPv6S1 network, so as follow-up when transmitting the IPv6 message of this route, can judge whether that needs carry out the operation of burst to message according to the size of MTU3.
Through after the above-mentioned steps 1～4, what preserve among the R2 is the minimum value that the route that arrives the IPv6S1 network is respectively jumped MTU, after R2 receives that the IPv6S2 network is sent to the IPv6 message of IPv6S1 network; The size of the MTU3 of the size of this message and preservation is compared, and whether decision needs burst, if carry out burst; The length of the message behind the burst is the minimum value of MTU that arrives the route of IPv6S1 network; Therefore, the P equipment between R2 and R1 can not exceed size and the dropping packets of the MTU of this route outgoing interface because of the size of message length, in R1; Can not carry out the Fragmentation of message more yet, improve message forwarding efficient.
Second instance:
This instance adopts the network topology of the IPv6 network interconnection of striding autonomous territory shown in Figure 2; Wherein the IPv6S1 network links to each other with the IPv6S2 network through AS1, AS2; AS1 is made up of 6PE-1, P and ASBR1; AS2 is made up of ASBR2 and 6PE-2, and AS1 and AS2 belong to the IPv4-MPLS network, and 6PE-1 and 6PE-2 are operator edge devices.
In order to realize that the IPv6 message of IPv6S2 network is sent to the IPv6S1 network, need be before message to send, each is carried out the routing device of bgp protocol and carries out the step that MTU learns respectively according to following flow process:
Step 1 ', 6PE-1 arrives the bgp routing information of IPv6S1 network to ASBR1 announcement, in the BGP route of announcement, carries the MTU1 of the route of this IPv6S1 network of arrival that 6PE-1 determines;
S501 is similar with step, and 6PE-1 carries MTU1 through the extended community attribute in the routing iinformation; 6PE-1 also comprises the information of next jumping of this BGP route in the bgp routing information of ASBR1 announcement, the information of this BGP next hop is the address of 6PE-1.
Step 2 ', ASBR1 is according to the address of the BGP next hop in the bgp routing information that receives, the MTU2 corresponding to this BGP route next jump surveys;
Step 3 ', the ASBR1 size of MTU1 and MTU2 relatively, with MTU3 value and the preservation of smaller value among both as this BGP route.
Step 4 ', ASBR1 confirms also to exist in this tunnel downstream bgp neighbor ASBR2;
Step 5 ', ASBR1 arrives the bgp routing information of IPv6S1 network to ASBR2 announcement, in this bgp routing information, carries the MTU3 of the route of this IPv6S1 network of arrival that ASBR1 determines.
Step 6 ', ASBR2 receives after this bgp routing information; Similar with the processing mode of ASBR1; Address according to the BGP next hop in this bgp routing information (ASBR1); The MTU4 corresponding to this BGP route next jump surveys, and ASBR2 compares the size of MTU4 and MTU3, with MTU5 and the preservation of smaller value among both as this BGP route.ASBR2 confirms also to exist in this tunnel downstream bgp neighbor 6PE-2, continues to arrive to the 6PE-2 announcement bgp routing information of IPv6S1 network, in this bgp routing information, carries the MTU5 of the route of this IPv6S1 network of arrival that ASBR2 determines.
Step 7 ', 6PE-2 receives after this bgp routing information, similar with the processing mode of ASBR2, according to the address of the BGP next hop in this bgp routing information (ASBR2), the MTU6 corresponding to this BGP route next jump surveys; 6PE-2 compares the size of MTU5 and MTU6, with MTU7 and the preservation of smaller value among both as this BGP route.Because 6PE-2 is the operator edge device that directly links to each other with the IPv6S2 network, therefore, the flow process of MTU study leaves it at that.
Through after the above-mentioned flow process; Preserve among the 6PE-2 be arrive the IPv6S1 network route respectively jump the minimum value among the MTU, after 6PE-2 receives that the IPv6S2 network is sent to the IPv6 message of IPv6S1 network, the size of the MTU7 of the size of this message and preservation is compared; Whether decision needs burst; If carry out burst, the length of the message behind the burst is the minimum value that arrives the MTU that respectively jumps in the route of IPv6S1 network, therefore; P equipment between 6PE-2 and 6PE-1 can not exceed because of the size of message length this route outgoing interface MTU size and abandon this IPv6 message; And in ASBR2, ASBR1 and 6PE-1, can not carry out the Fragmentation of message more yet, improve message forwarding efficient.
In above-mentioned two instances; After if the R1 of connection IPv6S1 network or 6PE-1 find that variation appears in the MTU1 of the outgoing interface that the route of arrival IPv6 network is corresponding; Can be to the bgp routing information of the MTU1 after its downstream neighbor R2 or ASBR1 announcement carries renewal, after R2 or ASBR1 receive this bgp routing information, can find that the MTU1 value of MTU1 and preservation in the bgp routing information of current reception is unequal; At this moment; MTU1 after relatively upgrading and the size of the local MTU2 that preserves are confirmed the smaller value among both, and when the MTU3 of smaller value of determining and preservation is unequal, and use this smaller value to upgrade the MTU3 that preserves; If ASBR1; Because also there is downstream neighbor ASBR2 in it; MTU3 after so also needing to upgrade is carried in the bgp routing information that arrives this IPv6 and announces to ASBR2; After ASBR2 receives this routing iinformation, carry out similar operation, in whole tunnel, obtain upgrading until the calculating of MTU.
In above-mentioned two instances; R2, ASBR1, ASBR2 or 6PE-2 can also be after the process of learning MTU first finish; Periodically the corresponding MTU of BGP route next jump that arrives this IPv6 network is surveyed automatically, and according to the result of automatic detection, the result of MTU study is upgraded.With ASBR1 is example; ASBR1 is when the MTU2 of current MTU2 that detects and preservation is unequal; Then need the MTU1 value that the value of the current MTU2 that detects is corresponding with this route of preservation compare the smaller value of confirming among both, and when the MTU3 of smaller value among both and preservation is unequal, use this smaller value to upgrade the MTU3 that preserves; MTU3 after upgrading is carried in the bgp routing information that reaches the IPv6S1 network and announces to ASBR2; After ASBR2 receives, the MTU that preserves is upgraded, also upgraded the MTU7 of its preservation until the operator edge device 6PE-2 that connects the IPv6S2 network according to aforementioned update method.
Based on same inventive concept; The embodiment of the invention also provides a kind of MTU learning device and routing device; Because the principle that this device and equipment are dealt with problems is similar with aforementioned a kind of MTU learning method; Therefore the enforcement of this device and routing device can repeat part and not give unnecessary details referring to the enforcement of method.
The learning device of a kind of MTU MTU that the embodiment of the invention provides, as shown in Figure 6, comprising:
Bgp routing information receiving element 601 is used to receive the bgp routing information of the arrival IPv6 network of IPv6 message transmissions tunnel middle and upper reaches Border Gateway Protocol (BGP) neighbor advertisement; Carry a MTU of the route of the arrival IPv6 network that said upper reaches bgp neighbor determines in the said bgp routing information;
Comparing unit 603 is used for the size with the 2nd MTU that detects with a more said MTU, with three MTU and the preservation of smaller value among both as the BGP route of the arrival IPv6 network of determining;
Advertising of route unit 604 is used for confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 said the 3rd MTU and announcement to said downstream bgp neighbor.
Further, above-mentioned advertising of route unit 604 is used for the extended community attribute of self-defined bgp routing information, and the type field of self-defining extended community attribute is set to MTU; The value of the 3rd MTU is encapsulated in the Value field of said extended community attribute.
Further, the learning device of the MTU that the embodiment of the invention provides also comprises: MTU updating block 605;
Correspondingly; Comparing unit 603; Also be used for the MTU value of a MTU and preservation of bgp routing information of at the upper reaches of bgp routing information receiving element 601 current receptions bgp neighbor announcement when unequal, the size of MTU in the said bgp routing information of more current reception and the 2nd MTU of preservation is confirmed the smaller value among both;
Advertising of route unit 604 is used for also confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and announcement to said downstream bgp neighbor.
Further; MTU probe unit 602 in the learning device of the MTU that the embodiment of the invention provides; Also be used for after advertising of route unit 604 is carried at said the 3rd MTU the bgp routing information and announcement to the step of said downstream bgp neighbor that arrives this IPv6 network, the 2nd MTU to the BGP route next jump that arrives this IPv6 network surveys periodically;
Comparing unit 603 also is used for when the 2nd MTU of MTU probe unit 602 current the 2nd MTU that detect and preservation is unequal, and a MTU of more current the 2nd MTU that detects and preservation confirms the smaller value among both;
Advertising of route unit 604 is used for also confirming whether the tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and the downstream bgp neighbor in announcement to the tunnel.
Further, when the learning device of the MTU that provides when the embodiment of the invention is arranged in the operator edge device that connects this IPv6 network, can also comprise:
Acquiring unit 606 is used for obtaining the MTU of the said operator edge device outgoing interface corresponding with the route that arrives the IPv6 network;
Correspondingly, advertising of route unit 604 is used for also confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 network the MTU that gets access to said outgoing interface and announcement to said downstream bgp neighbor.
The learning device of the MTU that the embodiment of the invention provides, in the specific implementation, can realize through design following function module: BGP module, routing table administration module, the automatic detecting module of MTU, wherein:
The BGP module is used to announce bgp routing information, preferably with the compute optimal route, upgrades the value of the corresponding MTU of route and to routing table the renewal route table items is installed.
The routing table administration module is used to manage route table items, like next jumping, the outgoing interface of confirming that route is corresponding, and the value of outgoing interface MTU, also be responsible for information simultaneously to BGP module announcement routing update.
The automatic detecting module of MTU is used for surveying automatically the transmission MTU value that arrives certain address, and reaches the MTU value of certain address to the announcement of BGP module.
In order to realize utilizing the above-mentioned MTU that learns to carry out data forwarding, in this device, data forwarding module can also be set, be used to utilize the MTU that learns to carry out the burst and the forwarding of data message.
The division of above-mentioned functions module and implementation only are instantiations, and the learning device of the MTU that the embodiment of the invention provides is not limited to above-mentioned concrete implementation.
The embodiment of the invention also provides a kind of routing device, and this routing device comprises the MT reconnaissance U learning device that the embodiment of the invention provides.
Preferably, the above-mentioned routing device that the embodiment of the invention provides when actual networking, can be used as operator edge device or Autonomous System Boundary Router, AS Boundary Router in the 6PE application scenarios.
The learning method of the MTU that the embodiment of the invention provides, device and routing device; For the routing device of each the operation BGP in the IPv6 message transmissions tunnel that forms in the IPv4 network, carry out following operation promptly: the bgp routing information that receives the arrival IPv6 network of upper reaches bgp neighbor announcement; This bgp routing information carries a MTU of the route of the arrival IPv6 network that this upper reaches bgp neighbor determines; The 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that the bgp routing information that receives is carried surveys; The size of the 2nd MTU that compares a MTU and detect is with three MTU and the preservation of smaller value among both as the BGP route of the arrival IPv6 network of determining; If also there is the downstream bgp neighbor; Then the 3rd MTU is carried at and also announces to downstream bgp neighbor in the bgp routing information that arrives this IPv6 network, the routing device of each the operation BGP in this tunnel has all learnt to arrive the corresponding MTU of BGP route of this IPv6 network.The embodiment of the invention is passed through the value that the BGP route is transmitted MTU between the operator edge device of supporting bgp protocol and autonomous system boundary route; The operator edge device that makes the terminal point in tunnel of transmission IPv6 message promptly connect another IPv6 network can calculate the minimum value of each MTU that jumps in the route that arrives purpose IPv6 network; And whether it need be carried out the foundation of burst as sending the IPv6 message; Through after the said process; When the terminal point in this tunnel is received the IPv6 message that mails to this IPv6 network; The size of the size of this message and the MTU that self preserves is compared, and whether decision needs burst, if carry out burst; The length of the message behind the burst is to arrive the minimum value of respectively jumping MTU in the route of this IPv6 network; Therefore, for especially striding the application scenarios that interconnects that the IPv6 networks are realized in the autonomous territory of a plurality of IPv4, no matter how many intermediate equipments (for example P equipment) or edge device need be crossed in the tunnel of IPv4 transmission through network IPv6 message through the application scenarios that interconnects of IPv4 network realization IPv6 network; Any intermediate equipment or edge device; Can not exceed because of the size of IPv6 message length this routing device outgoing interface MTU size and abandon this IPv6 message, thereby the situation of having avoided the transmission of the IPv6 message that existing 6PE technology occurs to be obstructed, and after the terminal point in this tunnel carries out Fragmentation to the IPv6 message of receiving; Other routing devices can not carried out the Fragmentation of message more yet in this tunnel, have improved IPv6 message forward efficiency in the tunnel.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, belong within the scope of claim of the present invention and equivalent technologies thereof if of the present invention these are revised with modification, then the present invention also is intended to comprise these changes and modification interior.
Claims (12)
1. the learning method of a MTU MTU is characterized in that, comprising:
Routing device for each the running boundary gateway protocol BGP in the IPv6 message transmissions tunnel that forms in the IPv4 network is carried out following operation:
Receive the bgp routing information of the arrival IPv6 network of IPv6 message transmissions tunnel middle and upper reaches Border Gateway Protocol (BGP) neighbor advertisement; Carry a MTU of the route of the arrival IPv6 network that said upper reaches bgp neighbor determines in the said bgp routing information;
The 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that the said bgp routing information that receives is carried surveys;
The size of a more said MTU and the 2nd MTU that detects is with three MTU and the preservation of the smaller value among both as the BGP route of the arrival IPv6 network of determining;
Confirm whether also there is the downstream bgp neighbor in the said tunnel,, be carried in the bgp routing information that arrives this IPv6 network said the 3rd MTU and announcement to said downstream bgp neighbor if exist; If do not exist, then finish the learning process of MTU.
2. the method for claim 1 is characterized in that, in the bgp routing information that arrives the IPv6 network, carries a MTU or the 3rd MTU, realizes through following manner:
Extended community attribute in the self-defined bgp routing information, the type field of self-defining extended community attribute is set to MTU; The value of the one MTU or the 3rd MTU is encapsulated in the Value field of said extended community attribute.
3. the method for claim 1; It is characterized in that; Said upper reaches bgp neighbor is when connecting the operator edge device of this IPv6 network, and a said MTU is the MTU of outgoing interface corresponding with the route that arrives the IPv6 network in the said operator edge device that obtains of said operator edge device.
4. like each described method of claim 1-3, it is characterized in that, also comprise:
Preserve the value of a said MTU value and said the 2nd MTU that detects.
5. method as claimed in claim 4 is characterized in that, when a MTU in the bgp routing information of the upper reaches of current reception bgp neighbor announcement and a MTU value of preservation are unequal, also comprises:
The size of a MTU in the said bgp routing information of more current reception and the 2nd MTU of preservation is confirmed the smaller value among both; And when the 3rd MTU of said smaller value and preservation is unequal; Use said smaller value to upgrade the 3rd MTU that preserves; Confirm whether also there is the downstream bgp neighbor in the said tunnel,, be carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and announcement to said downstream bgp neighbor if exist.
6. method as claimed in claim 4 is characterized in that, said the 3rd MTU is carried in the bgp routing information that arrives this IPv6 network and after announcement to the step of said downstream bgp neighbor, also comprises:
The 2nd MTU to the BGP route next jump that arrives this IPv6 network surveys periodically; And when the 2nd MTU of current the 2nd MTU that detects and preservation was unequal, a MTU of more current the 2nd MTU that detects and preservation confirmed the smaller value among both; And when the 3rd MTU of said smaller value and preservation is unequal; Use said smaller value to upgrade the value of the 3rd MTU that preserves; Confirm whether also there is the downstream bgp neighbor in the said tunnel; If exist, be carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and the downstream bgp neighbor in announcement to the tunnel.
7. the learning device of a MTU MTU is characterized in that, comprising:
The bgp routing information receiving element is used to receive the bgp routing information of the arrival IPv6 network of IPv6 message transmissions tunnel middle and upper reaches Border Gateway Protocol (BGP) neighbor advertisement; Carry a MTU of the route of the arrival IPv6 network that said upper reaches bgp neighbor determines in the said bgp routing information;
The MTU probe unit, the 2nd corresponding MTU of BGP route next jump of this IPv6 network of arrival that is used for the said bgp routing information that receives is carried surveys;
Comparing unit is used for the size with the 2nd MTU that detects with a more said MTU, with three MTU and the preservation of smaller value among both as the BGP route of the arrival IPv6 network of determining;
The advertising of route unit is used for confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 network said the 3rd MTU and announcement to said downstream bgp neighbor.
8. device as claimed in claim 7 is characterized in that, said advertising of route unit is further used for the extended community attribute in the self-defined bgp routing information, and the type field of self-defining extended community attribute is set to MTU; The value of the 3rd MTU is encapsulated in the Value field of said extended community attribute.
9. like claim 7 or 8 described devices, it is characterized in that, also comprise: the MTU updating block;
Said comparing unit; Also be used for the MTU value of a MTU and preservation of bgp routing information of at the upper reaches of the current reception of bgp routing information receiving element bgp neighbor announcement when unequal, the size of MTU in the said bgp routing information of more current reception and the 2nd MTU of preservation is confirmed the smaller value among both;
Said MTU updating block is used for when the 3rd MTU of said smaller value and preservation is unequal, uses said smaller value to upgrade the 3rd MTU that preserves;
Said advertising of route unit is used for also confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and announcement to said downstream bgp neighbor.
10. like claim 7 or 8 described devices, it is characterized in that, also comprise: the MTU updating block;
Said MTU probe unit; Also be used for after the advertising of route unit is carried at said the 3rd MTU the bgp routing information and announcement to the step of said downstream bgp neighbor that arrives this IPv6 network, the 2nd MTU to the BGP route next jump that arrives this IPv6 network surveys periodically;
Said comparing unit also is used for when the 2nd MTU of current the 2nd MTU that detects of said MTU probe unit and preservation is unequal, and a MTU of more current the 2nd MTU that detects and preservation confirms the smaller value among both;
Said MTU updating block is used for when the 3rd MTU of said smaller value and preservation is unequal, uses said smaller value to upgrade the value of the 3rd MTU that preserves;
Said advertising of route unit is used for also confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 the 3rd MTU after upgrading and the downstream bgp neighbor in announcement to the tunnel.
11. device as claimed in claim 7 is characterized in that, when said device is arranged in the operator edge device that connects this IPv6 network, also comprises:
Acquiring unit is used for obtaining the MTU of the said operator edge device outgoing interface corresponding with the route that arrives the IPv6 network;
Said advertising of route unit is used for also confirming whether said tunnel also exists the downstream bgp neighbor, if exist, is carried in the bgp routing information that arrives this IPv6 network the MTU that gets access to said outgoing interface and announcement to said downstream bgp neighbor.
12. a routing device is characterized in that, comprises the learning device like each described MTU MTU of claim 7～11.
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Families Citing this family (10)
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| CN102195888A (en) * | 2011-06-01 | 2011-09-21 | 华为技术有限公司 | Method and device for acquiring MTU (Maximum Transmission Unit) for forwarding guidance in BGP LSP (Border Gateway protocol Label Switched Path) |
| CN102594677A (en) * | 2012-02-15 | 2012-07-18 | 杭州华三通信技术有限公司 | Method and device for path maximum transmission unit (PMTU) learning |
| CN103166846B (en) * | 2013-03-27 | 2016-11-09 | 杭州华三通信技术有限公司 | A kind of message forwarding method and equipment |
| CN103220217B (en) * | 2013-04-27 | 2016-05-04 | 杭州华三通信技术有限公司 | A kind of route generating method and equipment |
| CN105634770B (en) * | 2014-10-29 | 2019-05-07 | 新华三技术有限公司 | The method and apparatus for disposing virtual extended local area network |
| CN104601469B (en) * | 2015-01-12 | 2018-01-12 | 新华三技术有限公司 | Method for forwarding multicast message and equipment |
| CN108965122B (en) * | 2017-05-19 | 2022-03-11 | 中兴通讯股份有限公司 | Routing method, device and computer readable storage medium |
| CN110391984B (en) * | 2019-07-26 | 2022-01-25 | 新华三大数据技术有限公司 | Message forwarding method and device |
| US20230006941A1 (en) * | 2021-07-01 | 2023-01-05 | Vmware, Inc. | Hypervisor implemented pmtu functionality and fragmentation in a cloud datacenter |
| US11962493B2 (en) | 2022-06-21 | 2024-04-16 | VMware LLC | Network address translation in active-active edge cluster |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1494296A (en) * | 2002-10-10 | 2004-05-05 | ض� | Defining network path transmission unit |
| KR20060011656A (en) * | 2004-07-30 | 2006-02-03 | 삼성전자주식회사 | System and method for setting packet maximum transmission unit of ipv6 transition tunnel using packet too big message |
| CN101616078A (en) * | 2009-07-16 | 2009-12-30 | 杭州华三通信技术有限公司 | A kind of discover method of PMTU, router and node device |
| CN101640645A (en) * | 2009-09-09 | 2010-02-03 | 中兴通讯股份有限公司 | Message transmission method and system |
-
2010
- 2010-11-18 CN CN2010105499431A patent/CN101977156B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1494296A (en) * | 2002-10-10 | 2004-05-05 | ض� | Defining network path transmission unit |
| KR20060011656A (en) * | 2004-07-30 | 2006-02-03 | 삼성전자주식회사 | System and method for setting packet maximum transmission unit of ipv6 transition tunnel using packet too big message |
| CN101616078A (en) * | 2009-07-16 | 2009-12-30 | 杭州华三通信技术有限公司 | A kind of discover method of PMTU, router and node device |
| CN101640645A (en) * | 2009-09-09 | 2010-02-03 | 中兴通讯股份有限公司 | Message transmission method and system |
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