CN101984596B - Method, device and routing equipment for avoiding black holes - Google Patents
Method, device and routing equipment for avoiding black holes Download PDFInfo
- Publication number
- CN101984596B CN101984596B CN2010105313907A CN201010531390A CN101984596B CN 101984596 B CN101984596 B CN 101984596B CN 2010105313907 A CN2010105313907 A CN 2010105313907A CN 201010531390 A CN201010531390 A CN 201010531390A CN 101984596 B CN101984596 B CN 101984596B
- Authority
- CN
- China
- Prior art keywords
- routing device
- path
- route
- value
- path cost
- 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.)
- Active
Links
Images
Abstract
The invention discloses a method, device and routing equipment for avoiding black holes. The method comprises the following steps: the second routing equipment computes a second path cost value between the first routing equipment and the second routing equipment according to a first path cost value and a corresponding multiple value in the path cost type length value (TLV) sent by the first routing equipment; the second path cost value meets the condition that when the second path cost value is used for carrying out routing computation, in the same routing, the path cost value of each path which passes through the first routing equipment is greater than the path cost value of each path which does not pass through the first routing equipment; and the second routing equipment forwards a data message through a backup path which does not pass through the first routing equipment according to the second path cost value. The invention ensures that under a narrow measurement mode of the intermediate system to intermediate system (IS-IS) protocol, in a short time after the first routing equipment finishes the restart, the second routing equipment certainly forwards the data message through the backup path which does not pass through the first routing equipment, thereby more reliably solving the problem of routing black holes.
Description
Technical field
The present invention relates to computer network communication field, relate in particular to a kind of method, device and routing device of avoiding path black hole.
Background technology
A network generally is made up of many routing devices; Work in coordination between the different routing devices and accomplish the forwarding of user data; Arriving destination address (such as address D) if a routing device (such as device A) is known through Routing Protocol study needs through another routing device (such as equipment B); Routing device B does not but arrive the route of destination address D, and the user data that routing device A will arrive destination address D is transmitted to routing device B, and routing device B is not owing to there is the route of destination address D; Can only data be abandoned; This phenomenon is called " path black hole " (Black hole), this phenomenon generally speaking the duration shorter, so also claimed instantaneous path black hole (Transient Black hole).
Scene with the instantaneous path black hole of Fig. 1 is an example; Source host S among Fig. 1 will be through too much platform routing device in the middle of wanting access server D; Have two kinds of paths to walk: article one path is S-RTE-RTA-RTB-RTD-RTF-D, and the second path is S-RTE-RTA-RTC-RTD-RTF-D.Routing device RTA, RTB, RTC, RTD running boundary gateway protocol (Border Gateway Protocol in the autonomous territory 1; BGP) and Intermediate System to Intermediate System (Intermediate System to Intermediate System; IS-IS); The bgp protocol module of each router is responsible for learning the route (route in autonomous territory 2 and autonomous territory 3) in other autonomous territories, and the Intermediate System to Intermediate System module then is responsible for the route learning in the autonomous territory 1.Under the normal condition, routing device RTA knows that through its bgp protocol modules learn next jumping that arrives destination server D is RTD, how to arrive RTD as for RTA, and the bgp protocol module can not be known, and need be learnt by its Intermediate System to Intermediate System module.The IS-IS module knows that through study RTA both can pass through RTB; Also can arrive RTD through RTC; Because RTA is that the path cost value is little through the line quality good (higher such as bandwidth) that RTB arrives RTD, through balance, RTA finally selects RTB as next jumping that arrives RTD.Like this, source host S select article one path be S-RTE-RTA-RTB-RTD-RTF-D as main path access server D, the second path is just selected for use when having only article one path obstructed as backup path.
In network operation process, if RTB owing to electricity under the reasons such as device upgrade or hardware fault is restarted, article one path S-RTE-RTA-RTB-RTD-RTF-D moment just is done for, source host S selects second path access server D rapidly.
RTB is restarted and is finished; Send the Intermediate System to Intermediate System message immediately; Rapid and RTA, RTD set up the is-is neighbor relation and accomplish routing convergence; RTA has known that through Intermediate System to Intermediate System RTB recovers normal, and according to the IS-IS routing select result, at this moment source host S should promptly communicate by letter through restarting between routing device RTB and the server D through main path.
Set up is-is neighbor simultaneously at RTB and RTA, RTD, RTB also will set up bgp neighbor with RTA, RTD, compares with the quick convergence of IS-IS route, and the convergence of BGP route is just slow a lot.The slow reason of BGP routing convergence is following: at first; BGP every once connects at a distance from 15 seconds (default time) and bgp neighbor trial, if the IP address of bgp neighbor is direct-connected address, bgp neighbor settling time is 0～15 second so; And under a lot of situation; Bgp neighbor IP address must be learnt through Intermediate System to Intermediate System, and bgp neighbor must wait the IS-IS routing convergence to accomplish could to begin to set up so, and settling time will be above 15 seconds.Secondly; After bgp neighbor is set up; The bgp protocol module of router begins synchronous a large amount of outside routes and goes forward side by side walking along the street by calculating; Install according to result of calculation at last and be routed to routing table, these operations all can more particularly be installed and be routed to the consuming time bigger of routing table in a large number than IS-IS routing convergence process.
RTA knew to arrive RTD through RTB through IS-IS when, RTB did not also learn the BGP route of server D.Like this, when the data forwarding that will arrive server D as RTA was given RTB, RTB can only abandon data owing to do not arrive the BGP route of server D, has caused instantaneous path black hole, learns the BGP route of server D through bgp protocol up to RTB.
Existing standard RFC3277 proposes following solution to the problem of above-mentioned path black hole:
In case routing device is restarted completion; And after setting up is-is neighbor relation with other routing devices; All path cost values through the routing device of restarting (below be called restart routing device) are provided with very highly and pass through the Link State packet (Link State Packets, LSP) message sends immediately.After neighbours receive this LSP message,, find to restart the path cost of the path cost of routing device, so continue to select backup path to transmit data greater than backup path through this through comparing path cost.When the BGP route is accomplished convergence or spent the fixed time (such as 5 minutes); Restarting routing device sends the LSP message carry the normal route overhead value and issues neighbours; After neighbours receive; Reselect this according to the Intermediate System to Intermediate System learning outcome and restart routing device and send out data as next redirect, like this, path black hole has just been avoided.For example among Fig. 1, after RTB is restarted,, just send immediately and carry the LSP message of high path cost value, after RTA receives, continue to use RTC as next jumping that arrives server D if set up new neighborhood with RTA.Accomplish or spent the fixed time when the BGP of RTB convergence, RTB sends and carries the LSP message of normal route overhead value, after RTA receives, selects RTB as next jumping that arrives RTD according to the Intermediate System to Intermediate System learning outcome.
But there is following problems in above-mentioned solution:
Under the narrow measurement pattern of Intermediate System to Intermediate System (narrow metric); Because can only using 6 bits that path cost is set, Intermediate System to Intermediate System message regulation is that maximum can only be for 63 (for example RTB can only be set to 63 to the path cost maximum of RTA among Fig. 1); If the backup path overhead is than the path overhead big by 63 (or bigger) through restarting routing device; Even will be arranged to maximum 63 through the path cost of restarting routing device so; Data also can be transmitted through the path of restarting routing device, still can not avoid the problem of instantaneous path black hole.In addition; Rely on the BGP convergence to accomplish or cross the fixed time (such as 5 minutes) and data are switched back the way of main line from backup path; If the setting of life period value is too little, and BGP route enormous amount has little time to restrain, the problem of instantaneous path black hole still exists.
Summary of the invention
The present invention provides a kind of method, device and routing device of avoiding path black hole, in order to solve the problem of the path black hole that after the router completion is restarted, produces in the prior art more reliably.
A kind of method of avoiding path black hole provided by the invention comprises:
Receive said first routing device as the neighbours' of first routing device of restarting secondary route equipment and restart the first Link State packet LSP message that send the back in completion;
Said secondary route equipment extracts the path cost type-length-value TLV that a said LSP message carries; According to the actual first path overhead value and the multiple value of the said first path overhead value between first routing device and the secondary route equipment among the said path cost TLV, calculate the second path cost value between said first routing device and the secondary route equipment; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said secondary route equipment carries out route according to the said second path cost value and calculates, and according to result of calculation will be not route through said first routing device be mounted to routing table.
Two of a kind of method of avoiding path black hole that the embodiment of the invention provides comprises:
First routing device is set up neighborhood with secondary route equipment after accomplishing and restarting;
Said first routing device is according to first actual between self and the secondary route equipment path overhead value and preset and the corresponding multiple value of the said first path overhead value, generation pass expense type-length-value TLV; The product of said first path overhead value and said multiple value satisfies: said product is carried out route when calculating as the path cost value between first routing device and the secondary route equipment, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said path cost TLV is carried in the first Link State packet LSP message is sent to said secondary route equipment;
Said secondary route equipment extracts the path cost TLV that a said LSP message carries; According to the actual first path overhead value and the multiple value of the said first path overhead value between first routing device and the secondary route equipment among the said path cost TLV, calculate the second path cost value between said first routing device and the secondary route equipment; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said secondary route equipment carries out route according to the said second path cost value and calculates, and according to result of calculation will be not route through said first routing device be mounted to routing table.
The device of avoiding path black hole that the embodiment of the invention provides comprises:
Receiving element, neighbours' routing device of routing device is restarted the first Link State packet LSP message that send the back in completion under being used to receive;
The path cost computing unit; Be used to extract the path cost type-length-value TLV that a said LSP message carries; The actual first path overhead value and the multiple value of the said first path overhead value between neighbours' routing device of restarting according to routing device under among the said path cost TLV and this completion, the second path cost value between neighbours' routing device that routing device and this completion are restarted under calculating; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value in the path of neighbours' routing device that same route is restarted through this completion is all greater than the path cost value in the path of neighbours' routing device of not restarting through this completion;
The routing update unit is used for carrying out route according to the said second path cost value and calculates, and according to result of calculation will be not route through said first routing device be mounted to routing table.
One of routing device that the embodiment of the invention provides comprises the above-mentioned device of avoiding path black hole that the embodiment of the invention provides.
Two of the routing device that the embodiment of the invention provides comprises:
Neighbours set up the unit, be used for affiliated routing device accomplish restart after, the neighborhood under setting up between routing device and the routing device that is adjacent;
Path cost type-length-value TLV generation unit is used for according to first actual between affiliated routing device and the neighbours' routing device path overhead value and preset and the corresponding multiple value of the first path overhead value, generation pass expense type-length-value TLV; The product of said first path overhead value and said multiple value satisfies: use said product is carried out route when calculating as the path cost value between affiliated routing device and the neighbours' routing device, the path cost value of same route through the path of routing device under this is all greater than the path cost value in the path through routing device under this not;
Transmitting element is used for that said path cost TLV is carried at the first Link State packet LSP message and is sent to said neighbours' routing device;
Receiving element, neighbours' routing device of routing device is restarted the first Link State packet LSP message that send the back in completion under being used to receive;
The path cost computing unit; Be used to extract the path cost TLV that a said LSP message carries; The actual first path overhead value and the multiple value of the said first path overhead value between neighbours' routing device of restarting according to routing device under among the said path cost TLV and this completion, the second path cost value between neighbours' routing device that routing device and this completion are restarted under calculating; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value in the path of neighbours' routing device that same route is restarted through this completion is all greater than the path cost value in the path of neighbours' routing device of not restarting through this completion;
The routing update unit is used for carrying out route according to the said second path cost value and calculates, and according to result of calculation will be not route through said first routing device be mounted to routing table.
The beneficial effect of the embodiment of the invention comprises:
The method of avoiding path black hole, device and routing device that the embodiment of the invention provides; Secondary route equipment as the neighbours of first routing device of restarting receives the LSP message that carries path cost TLV that first routing device sends; Secondary route equipment is according to first actual between first routing device among this path cost TLV and secondary route equipment path overhead value and corresponding multiple value; Calculate the second path cost value between first routing device and the secondary route equipment; The second path cost value satisfies when using this second path cost value to carry out route calculating; Same route is passed through the path cost value of first routing device all greater than the path cost value of not passing through the path of first routing device; Like this; Can guarantee in first routing device is accomplished the blink after restarting (the not convergence completion as yet of BGP route this moment) that secondary route equipment must not transmitted data message through the first via by the backup path of equipment through other, has avoided under the narrow measurement pattern of prior art; Even the path cost between first routing device itself and second equipment is set to maximum, because the excessive problem that causes the path black hole that the first via that data message passes through not learn the BGP route forms by device forwards of backup path overhead value.
Description of drawings
The sketch map of the scene of the instantaneous path black hole that Fig. 1 provides for existing RFC3277;
One of flow chart of the method for avoiding path black hole that Fig. 2 provides for the embodiment of the invention;
The sketch map of the form of the path cost TLV that Fig. 3 provides for the embodiment of the invention;
Two of the flow chart of the method for avoiding path black hole that Fig. 4 provides for the embodiment of the invention;
Fig. 5 provide for the embodiment of the invention next jump the sketch map of the form of TLV;
Three of the flow chart of the method for avoiding path black hole that Fig. 6 provides for the embodiment of the invention;
Four of the flow chart of the method for avoiding path black hole that Fig. 7 provides for the embodiment of the invention;
One of structural representation of the device of avoiding path black hole that Fig. 8 provides for the embodiment of the invention;
Two of the structural representation of the device of avoiding path black hole that Fig. 9 provides for the embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing, a kind of method, device and routing device of path black hole avoided that the embodiment of the invention provides at length explained respectively.
The method of avoiding path black hole that the embodiment of the invention provides, as shown in Figure 2 in a side as the neighbours' of first routing device of restarting secondary route device equipment, comprise the steps:
S201, secondary route equipment receive first routing device and restart first Link State packet (Link-State Packet, LSP) message that send the back in completion;
S202, secondary route equipment extract the path cost type-length-value (Type-Length-Value that a LSP message carries; TLV); According to the actual first path overhead value multiple value corresponding between first routing device and the secondary route equipment among this path cost TLV, calculate the second path cost value between said first routing device and the secondary route equipment with this preset first path overhead value;
In this step S202, the second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value of same route through the path of first routing device is all greater than the path cost value in the path through first routing device not;
S203, secondary route equipment carry out route according to the second path cost value and calculate, and upgrade local routing table according to result of calculation;
Be elaborated in the face of above-mentioned each step down.
After above-mentioned steps S201; All LSP messages as this first routing device transmission before restarting of the neighbours' of first routing device the local LSP message data of secondary route device clear library storage; A LSP message that receives is stored, and interfaces forwarding that floods through other operation Intermediate System to Intermediate Systems except the interface that connects this first routing device.
In above-mentioned steps S202; It is different that first routing device sends to a LSP message and the LSP message of the prior art of secondary route equipment; In a LSP message; Carried the path cost TLV of embodiment of the invention definition, as shown in Figure 3 is the sketch map of a concrete form of path cost TLV.
In this path cost TLV, comprise:
The types value field;
The length value field;
Path normal value field;
Path multiple value field.
Above-mentioned path normal value field; Write down the Actual path overhead value of confirming according to concrete network condition between first routing device and the secondary route equipment (i.e. the first path overhead value); Definite method of the Actual path overhead value between first routing device and the secondary route equipment belongs to the state of the art, repeats no more at this.
Above-mentioned path multiple value field; Write down the multiple value of predefined path cost value; This multiple value must satisfy following conditions: calculate if use this multiple value and the first path overhead value multiplied result to carry out route as the path cost value between first routing device and the secondary route equipment, the path cost value of same route through all paths of first routing device after restarting is all greater than the path cost value in the path of first routing device after not restarting through this.
The multiple value of the first path overhead value preestablishes and is arranged in first routing device, when setting this multiple value, if having many through the path of first routing device; The path multiple value can be finely tuned according to the bandwidth in each path; The path that bandwidth is big, can with multiple value be provided with slightly little, the path that bandwidth is little; Can with multiple value be provided with big slightly, but all must satisfy aforesaid condition.
In the specific implementation; Send in the LSP message of secondary route equipment at first routing device; Can also carry the path cost maximum that the Intermediate System to Intermediate System permission is provided with simultaneously; After secondary route equipment receives a LSP message, be in narrow measurement pattern if this secondary route equipment is current, the above-mentioned steps S202 that provides according to the embodiment of the invention so～S203 evades path black hole; Be not in narrow measurement pattern if this secondary route equipment is current, can promptly directly use this path cost maximum carry out route according to the way of prior art so and calculate as the path cost value between first routing device and the secondary route equipment.Certainly, no matter whether secondary route equipment is in narrow measurement pattern, carry out the problem that above-mentioned steps S201～S203 can both avoid path black hole.
In above-mentioned steps S202; Secondary route equipment is according to according to the actual first path overhead value and the multiple value of this first path overhead value between first routing device and the secondary route equipment among this path cost TLV; Calculate the process of the second path cost value between said first routing device and the secondary route equipment, the multiple value of the first path overhead value and first overhead value is multiplied each other obtains the process of the second path cost value exactly.The second path cost value can be evaded the restriction of existing Intermediate System to Intermediate System to the peaked size of path cost; Guarantee that secondary route equipment is after first routing device has just been restarted; Use this second path cost value to carry out the route result calculated, will be without the path of this first routing device of restarting as the path of transmitting data message.
In above-mentioned steps S203, secondary route renewal of the equipment local routing table, the route that will not comprise first routing device exactly is mounted to the process of local routing table.Secondary route equipment carries out route according to the second path cost value and calculates; Because all of same route are through the path cost value in the path of this first routing device; All greater than the path cost value of not passing through the path of this first routing device; Be optimum route calculative strategy according to path cost value minimum so; Must be with the path of not passing through this first routing device as result of calculation; The route that just will not include this first routing device is mounted to local routing table, and secondary route equipment is transmitted the data message that destination address belongs to other autonomous territories that link to each other for the routing device with this autonomous territory BGP route outlet via the route that does not comprise this first routing device thus.
Network topological diagram with Fig. 1 is an example; The routing device RTB of restarting sends a LSP message to its neighbours RTA; RTA calculates the second path cost value between RTA and the RTB according to the path cost TLV in the LSP message, and carries out route according to this second path cost value and calculate; In RTB was restarted the blink after accomplishing, selecting subsequent use path was that transmit from the message of source host S transmission in the path of RTA-RTC-RTD.Can avoid like this before the BGP convergence is accomplished, RTA selects the message that source host S sends is sent to RTB, and RTB does not accomplish owing to the BGP convergence as yet, thereby can't know that the BGP route that arrives server D abandons the path black hole problem that this message produces.
In order to let the main path of process RTB recover as early as possible to use; No matter whether the BGP convergence restrains to accomplish and is about to the data message forwarding path and goes back to the path black hole problem that primary path (via the path of first routing device) is brought after avoiding in the prior art waiting for the fixed time; The embodiment of the invention is that secondary route equipment will be not after route through said first routing device is mounted to routing table at above-mentioned steps S203; As shown in Figure 4, also carry out following step:
S401, the secondary route equipment utilization first path overhead value are carried out route and are calculated;
In this step S401, secondary route equipment carries out route with the first path overhead value as the path cost value between self and first routing device (also promptly using real path cost value between the two) and calculates.
S402, judge that according to the route result calculated whether first routing device is next jumping of best IS-IS to the outlet of BGP route, if carry out following step S403 so, otherwise withdraw from this flow process.
S403, secondary route equipment generate next and jump path TLV, this next jump path TLV comprise as the sign of the routing device of BGP route outlet and as the first via of best next jumping of IS-IS by equipment mark;
It is as shown in Figure 5 that next jumps the form of path TLV in the embodiment of the invention, this next jump the byte of sign of identification byte and best next jumping of IS-IS that path TLV comprises the routing device of types value byte, length value byte and the outlet of BGP route.Among this TLV shown in Figure 5, indicated the ID of the routing device that arrives a plurality of BGP route outlets, and the ID (ID of first routing device just) of corresponding best next jumping of IS-IS.In the specific implementation; This next jump ID and the ID of corresponding best next jumping of IS-IS that path TLV also can only carry the routing device of a BGP route outlet; When next jumps the ID of the routing device that comprises a plurality of BGP route outlets among the TLV of path; Can also after the ID of the routing device that each BGP route exports, increase and carry the corresponding QoS mark of this BGP route outlet.
S404, secondary route equipment accomplish local LSP database and its neighbours' routing device the LSP database synchronously;
Next jumping path TLV that S405, secondary route equipment generate step S403 is carried at and is sent to first routing device in the hello packet.
First routing device is received the handling process after this hello packet, further specifies in the description process of following first routing device, one side.
The method of avoiding path black hole that the embodiment of the invention provides, as shown in Figure 6 in a side as first routing device of restarting, comprise the steps:
After S601, first routing device of restarting are accomplished and are restarted and the secondary route equipment that is adjacent set up neighborhood;
S602, first routing device are according to first actual between self and the secondary route equipment path overhead value and preset and the corresponding multiple value of the first path overhead value, generation pass expense TLV; The product of this first path overhead value and multiple value satisfies: product is carried out route when calculating as the path cost value between first routing device and the secondary route equipment, and all path cost values through the path of first routing device of same route are all greater than the path cost value in the path through first routing device not;
S603, path cost TLV is carried in the LSP message is sent to secondary route equipment.
Need to prove that the time of implementation of this step S601～S603 is before step S201 shown in Figure 2.
After above-mentioned steps S603, just above-mentioned secondary route equipment will generate next jump path TLV be carried at be sent to first routing device in the hello packet after, as shown in Figure 7, also comprise the steps:
S701, first routing device receive the hello packet that carries next jumping TLV that secondary route equipment sends; Next jumps the sign of routing device of best next jumping of IS-IS of sign and secondary route equipment that path TLV comprises the routing device of BGP route outlet;
S702, first routing device confirm that the routing device of best next jumping of IS-IS of secondary route equipment is self, carry out route and calculate, and judge whether to reach the routing device of BGP route outlet; If judged result is for being to carry out following step S703; If not, withdraw from this flow process.
S703, first routing device generate IS-IS strategy route and are saved in the local routing table; This IS-IS strategy route has defined the route that the data message forwarding that secondary route equipment is sent is given the routing device of BGP route outlet;
The priority of the priority of this strategy route and BGP route is equal to; If exist in first routing device than the higher route of BGP route priority; Should the strategy route not come into force so; First routing device will be according to the higher routing forwarding data of priority, but do not have under the situation of the route of high priority more, and first routing device will be transmitted data message according to the route of tactful route definition.
In this autonomous territory, have only under the situation of a BGP outlet; First routing device is when receiving the data message that secondary route equipment sends; If the data message (destination address belongs to this autonomous territory) in this data message autonomous territory that is this, so according to the IS-IS routing forwarding of having learnt, if this data message is not the data message in this autonomous territory; According to tactful route, directly get final product to the routing device of BGP route outlet this data message forwarding so.
If in abovementioned steps S402; Owing to there are a plurality of BGP route outlets in this autonomous territory; In the hello packet that secondary route equipment sends next jumped and carried the corresponding QoS mark of each BGP route outlet among the TLV of path; At this step S703 first routing device, also carry the corresponding QoS mark of this BGP route outlet in the IS-IS of the corresponding generation strategy route so.
Correspondingly; Can in data message, stamp the Qos mark of BGP route outlet during secondary route equipment sending data message; First routing device is after restarting completion so; Before the BGP routing convergence is accomplished, can be according to the Qos mark of the BGP route outlet in IS-IS strategy route and the data message, with the routing device of this data message forwarding to the BGP route outlet corresponding with the Qos mark.
S704, first routing device send the 2nd LSP message that does not carry path cost TLV to secondary route equipment.
In this step S704; The 2nd LSP message that first routing device sends to secondary route equipment can adopt the form of LSP message in the prior art; Promptly cancelled the LSP message of path cost TLV; Allow the path cost maximum that is provided with if except carrying path cost TLV, also carry Intermediate System to Intermediate System in the LSP message that sends before, in this step, first routing device also need be cancelled and carries this path cost maximum.First routing device only need carry the reality between first routing device and the secondary route equipment in the 2nd LSP message the first path overhead value gets final product.
After secondary route equipment is received the 2nd LSP message; Adopting first actual between first routing device and the secondary route equipment path overhead value to carry out route calculates; Select first routing device as next jumping that arrives the outlet of BGP route, need send to first routing device through the data message that the routing device of BGP route outlet is transmitted.First routing device is after the message of receiving the secondary route device forwards; Directly according to IS-IS strategy route, with the routing device of this data message forwarding to BGP route outlet, and need be in prior art; Need to wait for that BGP accomplishes convergence and perhaps waits for after the time of appointment; Data message could be sent to the routing device of BGP route outlet via first routing device, when avoiding path black hole, has also improved the switch speed of active-standby path.
Said process is an example with network topology shown in Figure 1; The RTB of restarting is according to next the jumping TLV in the hello packet of RTA transmission; Generate the tactful route that priority and BGP route are equal to; This strategy route indication RTB, if RTA transmit and destination address be certain equipment data messages of server D for example in the autonomous territory 2, be transmitted to the RTD that exports as BGP that links to each other with autonomous territory 2.
RTB is according to this strategy route, and the data message that mails to server D in the autonomous territory 2 that neighbours RTA is transmitted directly is transmitted to next jumping RTD.
In the routing device of the first via by the outlet of device forwards data message to BGP route, first routing device judges whether BGP restrains completion, accomplishes if judge the BGP convergence, and the first via is by the strategy of the IS-IS in unit deletion self routing table route.After this carry out data forwarding according to the indication of BGP route.
Based on same inventive concept; The embodiment of the invention also provides a kind of device and routing device of avoiding path black hole; Because this device of avoiding path black hole is similar with the aforementioned method of path black hole of avoiding with the principle that routing device is dealt with problems; Therefore the enforcement of the device that floods of this realization route and switch can be referring to the enforcement of method, and the repetition part repeats no more.
The embodiment of the invention provides avoids one of device of path black hole, as shown in Figure 8, comprising:
Receiving element 801, neighbours' routing device of routing device is restarted the first Link State packet LSP message that send the back in completion under being used to receive;
Path cost computing unit 802; Be used to extract the path cost type-length-value TLV that a LSP message carries; The actual first path overhead value and the multiple value of the said first path overhead value between neighbours' routing device of restarting according to routing device under among the said path cost TLV and this completion, the second path cost value between neighbours' routing device that routing device and this completion are restarted under calculating; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value in the path of neighbours' routing device that same route is restarted through this completion is all greater than the path cost value in the path of neighbours' routing device of not restarting through this completion;
Further, the device of avoiding path black hole that the embodiment of the invention provides, as shown in Figure 8, also comprise: next jumps TLV generation unit 804 and hello packet transmitting element 805; Wherein:
Path cost computing unit 802 also is used for after the route installation unit upgrades routing table, utilizes the said first path overhead value to carry out route and calculates;
Next jumps TLV generation unit 804; Being used for carrying out neighbours' routing device that the route result calculated confirms that this completion is restarted at said path cost computing unit 802 according to the first path overhead value is next jumping of best IS-IS to the outlet of BGP route, then generates next and jumps path TLV; Said next jumping path TLV comprises the sign of the routing device that said BGP route exports and the sign of neighbours' routing device that this completion is restarted;
Hello packet transmitting element 805; Be used for the local LSP database of router and its each neighbours' routing device under accomplishing the LSP database synchronously after, said next jumping path TLV is carried at is sent to neighbours' routing device that this completion is restarted in the hello packet.
The embodiment of the invention provides two of a kind of device of avoiding path black hole, as shown in Figure 9, specifically comprise:
Neighbours set up unit 901, be used for affiliated routing device accomplish restart after, the neighborhood under setting up between routing device and the routing device that is adjacent;
Path cost TLV generation unit 902 is used for according to first actual between affiliated routing device and the neighbours' routing device path overhead value and preset and the corresponding multiple value of the first path overhead value, generation pass expense TLV; The product of the first path overhead value and said multiple value satisfies: use said product is carried out route when calculating as the path cost value between affiliated routing device and the neighbours' routing device, the path cost value of same route through the path of routing device under this is all greater than the path cost value in the path through routing device under this not;
Transmitting element 903 is used for that said path cost TLV is carried at a LSP message and is sent to said neighbours' routing device.
Further, the above-mentioned device of avoiding path black hole that the embodiment of the invention provides, as shown in Figure 9, also comprise: hello packet receiving element 904, route computing unit 905 and IS-IS strategy route generation unit 906;
Hello packet receiving element 904 is used to receive the hello packet that carries next jumping TLV that said neighbours' routing device sends; Said next jump the sign of routing device of best next jumping of IS-IS of sign and said neighbours' routing device that path TLV comprises the routing device of BGP route outlet;
When route computing unit 905, the routing device that is used for confirming best next jumping of IS-IS of said neighbours' routing device are affiliated routing device, carry out route and calculate, whether routing device can reach the routing device of said BGP route outlet under judging;
IS-IS strategy route generation unit 906; Be used in the route computing unit judged result when being; Generate the priority IS-IS strategy route identical with the BGP route also be saved under in the routing device local routing table, said IS-IS strategy route has defined the route that the data message forwarding that said neighbours' routing device is transmitted is given the routing device that said BGP route exports;
Transmitting element 903 also is used for sending the 2nd LSP message that does not carry path cost TLV to said neighbours' routing device.
Further; Transmitting element 903 in the embodiment of the invention provides the above-mentioned device of avoiding path black hole; Also be used for after said neighbours' routing device sends the 2nd LSP message; According to said IS-IS strategy route, transmit the routing device of the data message of said neighbours' routing device transmission to said BGP route outlet.
Further, the above-mentioned device of avoiding path black hole that the embodiment of the invention provides, as shown in Figure 9; Can also comprise: delete cells 907; Be used to judge whether BGP restrains completion, and when the BGP convergence has been accomplished, the said IS-IS strategy route under the deletion in the routing device local routing table.
Two kinds of above-mentioned devices of avoiding path black hole that the embodiment of the invention provides can be arranged in the same routing device, also can on two different routing devices, realize respectively.
The embodiment of the invention also provides a kind of routing device, and this routing device includes above-mentioned two kinds that the embodiment of the invention provides simultaneously and avoids the device of path black hole or comprise wherein any one.
The method of avoiding path black hole, device and routing device that the embodiment of the invention provides; Secondary route equipment as the neighbours of first routing device of restarting receives the LSP message that carries path cost TLV that first routing device sends; Secondary route equipment is according to first actual between first routing device among this path cost TLV and secondary route equipment path overhead value and corresponding multiple value; Calculate the second path cost value between first routing device and the secondary route equipment; The second path cost value satisfies when using this second path cost value to carry out route calculating; All path cost values of passing through first routing device of same route are all greater than the path cost value of not passing through the path of first routing device; Like this; Can guarantee that in first routing device is accomplished the blink after restarting secondary route equipment must not transmitted data message through the first via by the backup path of equipment through other, has avoided under the narrow measurement pattern of prior art; Even the path cost between first routing device itself and second equipment is set to maximum, because the excessive problem that causes the path black hole that the first via that data message passes through not learn the BGP route forms by device forwards of backup path overhead value.
Further; The method of avoiding path black hole, device and routing device that the embodiment of the invention provides; Secondary route equipment carries out route according to the first path overhead value in the LSP message once more and calculates; If confirming first routing device is next jumping of best IS-IS that arrives the outlet of BGP route; Then generate next and jump TLV; And send to first routing device through hello packet; First routing device is jumped TLV according to next and is generated the tactful route that priority and BGP route are equal to, and this strategy route indication secondary route equipment sends the routing device that data message that destination address belongs to other autonomous territories that link to each other with the routing device of BGP route outlet is exported to BGP by device forwards via the first via, like this; Restart in the completion of first routing device; And before the BGP routing convergence accomplished as yet, the destination address that directly secondary route equipment is sent belonged to the data message forwarding in other autonomous territories and gives the routing device of BGP route outlet, and need not wait for as prior art that BGP accomplishes the use that convergence waits for that perhaps the time of appointment is just recovered this primary path afterwards; No matter whether the BGP route restrains the problem of the path black hole that completion promptly brings by the device forwards data message through the first via of restarting after not only having avoided available technology adopting to wait for the fixed time, but also has improved the speed of switching between backup path and the primary path.
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 (16)
1. a method of avoiding path black hole is characterized in that, comprising:
Receive said first routing device as the neighbours' of first routing device of restarting secondary route equipment and restart the first Link State packet LSP message that send the back in completion;
Said secondary route equipment extracts the path cost type-length-value TLV that a said LSP message carries; According to the actual first path overhead value and the multiple value of the said first path overhead value between first routing device and the secondary route equipment among the said path cost TLV, calculate the second path cost value between said first routing device and the secondary route equipment; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said secondary route equipment carries out route according to the said second path cost value and calculates, and upgrades routing table according to result of calculation, is about to not to be mounted to routing table through the route of said first routing device.
2. the method for claim 1 is characterized in that, the said second path cost value multiplies each other through the multiple value with said first path overhead value and the said first path overhead value and obtains.
3. according to claim 1 or claim 2 method is characterized in that, after the step of upgrading routing table, also comprises:
The said first path overhead value of said secondary route equipment utilization is carried out route and is calculated;
If confirm that according to the route result calculated said first routing device is next jumping to the best Intermediate System-to-Intermediate System IS-IS of Border Gateway Protocol (BGP) route outlet, then generates next and jumps path TLV; Said next jump path TLV comprise said BGP route outlet routing device sign and as the said first via of best next jumping of IS-IS by equipment mark;
Said secondary route equipment accomplish local LSP database and its neighbours' routing device the LSP database synchronously after, next is jumped path TLV is carried at and is sent to said first routing device in the hello packet.
4. the method for claim 1 is characterized in that, secondary route equipment receives after the LSP message of said first routing device transmission, also comprises:
Remove all LSP messages that said first routing device of local storage was sending before restarting, a LSP message that receives is stored and through the forwarding that floods of other interfaces that move Intermediate System to Intermediate Systems outside the interface that connects said first routing device.
5. a method of avoiding path black hole is characterized in that, comprising:
First routing device is set up neighborhood with secondary route equipment after accomplishing and restarting;
Said first routing device is according to first actual between self and the secondary route equipment path overhead value and preset and the corresponding multiple value of the said first path overhead value, generation pass expense type-length-value TLV; The product of said first path overhead value and said multiple value satisfies: said product is carried out route when calculating as the path cost value between first routing device and the secondary route equipment, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said path cost TLV is carried in the first Link State packet LSP message is sent to said secondary route equipment;
Said secondary route equipment extracts the path cost TLV that a said LSP message carries; According to the actual first path overhead value and the multiple value of the said first path overhead value between first routing device and the secondary route equipment among the said path cost TLV, calculate the second path cost value between said first routing device and the secondary route equipment; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value of same route through the path of said first routing device is all greater than the path cost value in the path through said first routing device not;
Said secondary route equipment carries out route according to the said second path cost value and calculates, and upgrades routing table according to result of calculation, is about to not to be mounted to routing table through the route of said first routing device.
6. method as claimed in claim 5 is characterized in that, first routing device path cost TLV is carried at be sent to the step of secondary route equipment in the LSP message after, also comprise:
First routing device receives the hello packet that carries next jumping TLV that said secondary route equipment sends; Said next jump the sign of routing device of next jumping of best Intermediate System-to-Intermediate System IS-IS of sign and said secondary route equipment that path TLV comprises the routing device of Border Gateway Protocol (BGP) route outlet;
When said first routing device confirms that the routing device of best next jumping of IS-IS of said secondary route equipment is self, carry out route and calculate, judge whether to reach the routing device of said BGP route outlet;
If judged result is for being; First routing device generates the priority IS-IS strategy route identical with the BGP route and is saved in the local routing table; Said IS-IS strategy route has defined the route that the data message forwarding that said secondary route equipment is sent is given the routing device of said BGP route outlet, and said first routing device sends the 2nd LSP message that does not carry path cost TLV to said secondary route equipment.
7. method as claimed in claim 6 is characterized in that, first routing device also comprises after secondary route equipment sends said the 2nd LSP message:
Receive the data message of secondary route device forwards;
According to said IS-IS strategy route, transmit routing device from data message to the said BGP route outlet of secondary route equipment.
8. like claim 6 or 7 described methods, it is characterized in that, also comprise: first routing device judges whether BGP restrains completion;
Accomplish if judge the BGP convergence, the first via is by the said IS-IS strategy route in unit deletion self routing table.
9. a device of avoiding path black hole is characterized in that, comprising:
Receiving element, neighbours' routing device of routing device is restarted the first Link State packet LSP message that send the back in completion under being used to receive;
The path cost computing unit; Be used to extract the path cost type-length-value TLV that a said LSP message carries; The actual first path overhead value and the multiple value of the said first path overhead value between neighbours' routing device of restarting according to routing device under among the said path cost TLV and this completion, the second path cost value between neighbours' routing device that routing device and this completion are restarted under calculating; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value in the path of neighbours' routing device that same route is restarted through this completion is all greater than the path cost value in the path of neighbours' routing device of not restarting through this completion;
The routing update unit is used for carrying out route according to the said second path cost value and calculates, and upgrades routing table according to result of calculation, is about to not to be mounted to routing table through the route of said neighbours' routing device.
10. device as claimed in claim 9 is characterized in that, also comprises: next jumps TLV generation unit and hello packet transmitting element;
Said path cost computing unit also is used for after the routing update unit upgrades routing table, utilizes the said first path overhead value to carry out route and calculates;
Said next jumping TLV generation unit; Being used at said path cost computing unit is when next is jumped to the best Intermediate System-to-Intermediate System IS-IS of Border Gateway Protocol (BGP) route outlet, to generate next and jump path TLV according to utilizing the first path overhead value to carry out neighbours' routing device that the route result calculated confirms that this completion is restarted; Said next jumping path TLV comprises the sign of the routing device that said BGP route exports and the sign of neighbours' routing device that this completion is restarted;
Said hello packet transmitting element; Be used for the local LSP database of routing device and its each neighbours' routing device under accomplishing the LSP database synchronously after, said next jumping path TLV is carried at is sent to neighbours' routing device that this completion is restarted in the hello packet.
11. a routing device is characterized in that, comprises like each described device of avoiding path black hole of claim 9～10.
12. a routing device is characterized in that, comprising:
Neighbours set up the unit, be used for affiliated routing device accomplish restart after, the neighborhood under setting up between routing device and the routing device that is adjacent;
Path cost type-length-value TLV generation unit is used for according to first actual between affiliated routing device and the neighbours' routing device path overhead value and preset and the corresponding multiple value of the first path overhead value, generation pass expense type-length-value TLV; The product of said first path overhead value and said multiple value satisfies: use said product is carried out route when calculating as the path cost value between affiliated routing device and the neighbours' routing device, the path cost value of same route through the path of routing device under this is all greater than the path cost value in the path through routing device under this not;
Transmitting element is used for that said path cost TLV is carried at the first Link State packet LSP message and is sent to said neighbours' routing device;
Receiving element, neighbours' routing device of routing device is restarted the first Link State packet LSP message that send the back in completion under being used to receive;
The path cost computing unit; Be used to extract the path cost TLV that a LSP message that said receiving element receives carries; The multiple value of the first actual path overhead value between neighbours' routing device that first path overhead value of reality and affiliated routing device and this completion are restarted between neighbours' routing device that routing device and this completion are restarted under among the path cost TLV that a LSP message that receives according to said receiving element carries, the second path cost value between neighbours' routing device that routing device and this completion are restarted under calculating; The said second path cost value satisfy to use this second path cost value to carry out route when calculating, and the path cost value in the path of neighbours' routing device that same route is restarted through this completion is all greater than the path cost value in the path of neighbours' routing device of not restarting through this completion;
The routing update unit is used for carrying out route according to the said second path cost value and calculates, and upgrades routing table according to result of calculation, and the route of the neighbours' routing device that is about to not to restart through this completion is mounted to routing table.
13. routing device as claimed in claim 12 is characterized in that, also comprises: hello packet receiving element, route computing unit and Intermediate System-to-Intermediate System IS-IS strategy route generation unit;
Said hello packet receiving element is used to receive the hello packet that carries next jumping TLV that said neighbours' routing device sends; Said next jump the sign of routing device of best next jumping of IS-IS of sign and said neighbours' routing device that path TLV comprises the routing device of Border Gateway Protocol (BGP) route outlet;
When said route computing unit, the routing device that is used for confirming best next jumping of IS-IS of said neighbours' routing device are affiliated routing device, carry out route and calculate, whether routing device can reach the routing device of said BGP route outlet under judging;
Said IS-IS strategy route generation unit; Be used in the route computing unit judged result when being; Generate the priority IS-IS strategy route identical with the BGP route also be saved under in the routing device local routing table, said IS-IS strategy route has defined the route that the data message forwarding that said neighbours' routing device is sent is given the routing device that said BGP route exports;
Said transmitting element also is used for sending the 2nd LSP message that does not carry path cost TLV to said neighbours' routing device.
14. routing device as claimed in claim 13; It is characterized in that; Said transmitting element; Also be used for after said neighbours' routing device sends the 2nd LSP message,, transmit the routing device of the data message of said neighbours' routing device transmission to said BGP route outlet according to said IS-IS strategy route.
15. like claim 13 or 14 described routing devices, it is characterized in that, also comprise:
Delete cells is used to judge whether BGP restrains completion, and when the BGP convergence has been accomplished, the said IS-IS strategy route under the deletion in the routing device local routing table.
16. routing device as claimed in claim 12 is characterized in that, also comprises: next jumps TLV generation unit and hello packet transmitting element;
Said path cost computing unit also is used for after the routing update unit upgrades routing table, and the first actual path overhead value is carried out route calculating between neighbours' routing device that routing device and this completion are restarted under utilizing;
Said next jumping TLV generation unit; Being used at said path cost computing unit is when next is jumped to the best Intermediate System-to-Intermediate System IS-IS of Border Gateway Protocol (BGP) route outlet, to generate next and jump path TLV according to utilizing the first path overhead value to carry out neighbours' routing device that the route result calculated confirms that this completion is restarted; Said next jumping path TLV comprises the sign of the routing device that said BGP route exports and the sign of neighbours' routing device that this completion is restarted;
Said hello packet transmitting element; Be used for the local LSP database of routing device and its each neighbours' routing device under accomplishing the LSP database synchronously after, said next jumping path TLV is carried at is sent to neighbours' routing device that this completion is restarted in the hello packet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105313907A CN101984596B (en) | 2010-11-04 | 2010-11-04 | Method, device and routing equipment for avoiding black holes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105313907A CN101984596B (en) | 2010-11-04 | 2010-11-04 | Method, device and routing equipment for avoiding black holes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101984596A CN101984596A (en) | 2011-03-09 |
| CN101984596B true CN101984596B (en) | 2012-05-30 |
Family
ID=43641767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105313907A Active CN101984596B (en) | 2010-11-04 | 2010-11-04 | Method, device and routing equipment for avoiding black holes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101984596B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103220221B (en) * | 2012-01-20 | 2017-04-12 | 华为技术有限公司 | Method and device capable of noticing link information |
| CN103297340B (en) * | 2013-06-07 | 2017-02-08 | 杭州华三通信技术有限公司 | Routing convergence method and device in multi-protocol label switching (MPLS) and border gateway protocol (BGP) networking |
| CN105007607B (en) * | 2014-04-24 | 2018-10-23 | 中国电信股份有限公司 | Route advertising method and system |
| CN107347032B (en) * | 2016-05-05 | 2019-09-10 | 中兴通讯股份有限公司 | Message forwarding method and device |
| CN107911298B (en) * | 2017-12-29 | 2020-03-06 | 杭州迪普科技股份有限公司 | ISIS-based routing redistribution method and device |
| CN109005121B (en) * | 2018-08-24 | 2021-06-29 | 新华三技术有限公司 | Route calculation method and device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100442767C (en) * | 2005-08-22 | 2008-12-10 | 广东省电信有限公司研究院 | Method for stable restart of router realizing fast route convergence |
| CN100531220C (en) * | 2006-12-05 | 2009-08-19 | 中兴通讯股份有限公司 | Optimum restarting realizing method for generating tree protocol in two-layer network device |
| CN100542143C (en) * | 2007-04-16 | 2009-09-16 | 杭州华三通信技术有限公司 | Graceful Restart method, designated intermediate system, neighbor router and radio network |
-
2010
- 2010-11-04 CN CN2010105313907A patent/CN101984596B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN101984596A (en) | 2011-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10356011B2 (en) | Partial software defined network switch replacement in IP networks | |
| CN101984596B (en) | Method, device and routing equipment for avoiding black holes | |
| RU2651149C2 (en) | Sdn-controller, data processing center system and the routed connection method | |
| CN103281247B (en) | The general method for routing of a kind of data center network and system | |
| US7155632B2 (en) | Method and system for implementing IS-IS protocol redundancy | |
| EP2093963B1 (en) | A method, system and path computation element for obtaining path information | |
| US20150180705A1 (en) | Controller placement for fast failover in the split architecture | |
| CN102377680B (en) | Route convergence method and device | |
| CN104270298A (en) | Method and device for forwarding message in VXLAN | |
| CN103703727A (en) | Method and apparatus for resilient routing of control traffic in a split-architecture system | |
| CN102664788A (en) | CE dual-homed link protection method in MPLS L3VPN and system thereof | |
| CN103155485A (en) | Fast flooding based fast convergence to recover from network failures | |
| CN102364900A (en) | FRR (Fast ReRoute) based data transmission method and device in IRF (Intelligent Resilient Framework) system | |
| CN101616091B (en) | Method for realizing fast re-routing of label distribution protocol and label switch router | |
| CN102611629B (en) | Fast re-route method and device in MPLS (Multi-Protocol Label Switching) | |
| EP2599270B1 (en) | A network device and method of routing traffic | |
| CN103281253A (en) | Load sharing method of non-equivalent route and equipment | |
| WO2016153506A1 (en) | Fast failover recovery in software defined networks | |
| CN103201987A (en) | Prioritization of routing information updates | |
| CN103532840B (en) | Link switching method and link switching device | |
| WO2023015897A1 (en) | Intelligent control method, apparatus and system for optical network | |
| CN102571425A (en) | Method and device for smoothly restarting border gateway protocol | |
| CN102882757A (en) | Point-to-multipoint service protecting method for ring network and upper ring node in ring network | |
| CN103139040A (en) | Extensional virtual private network (VPN) false refused rate (FRR) implement method and equipment | |
| CN105791113A (en) | SDN (Software Defined Network)-based multi-link delay equalization method and system |
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 |