CN100365986C

CN100365986C - Method for saving BGP routing table memory consumption

Info

Publication number: CN100365986C
Application number: CNB2003101184536A
Authority: CN
Inventors: 刘博旻
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Digital Technologies Chengdu Co Ltd
Priority date: 2003-12-17
Filing date: 2003-12-17
Publication date: 2008-01-30
Anticipated expiration: 2023-12-17
Also published as: CN1547355A

Abstract

The present invention provides a method for saving the memory consumption of a routing table of a boundary gateway protocol, which belongs to the field of computer network communication. The method comprises the steps that: when a local network receives or generates a routing, a Loc-Rib is used as a common sharing buffer pool so as to save all reached routing information; the mapping relationship of each routing in a Loc-Rib information base and Adj-Rib-Out is created; routings are transmitted to an arbitration decision module to be filtered by a local policy; if the routings pass the decision of the arbitration module, the proper routings for the local network is noticed to other Peers. The corresponding relationship between a routing in the Adj-Rib-Out information base and a certain routing in the Loc-Rib information base is created, so the Adj-Rib-Out doesn't need maintain a copy of a routing to be transmitted. Information can be shared by the present invention. The present invention saves a memorizer and obviously saves the memory consumption of a routing table of the BGP.

Description

The saving routing table memory consumption method of Border Gateway Protocol router

Affiliated technical field

The invention belongs to the broadband network communication field, be specifically related to the saving routing table memory consumption method of a kind of Border Gateway Protocol (BGP) router.

Background technology

BGP is used for realizing the discovery and the transmission of route as a class EGP agreement between autonomous system.Its basic function is exactly the announcement and the storage of route.Between bgp peer, carry out the exchange of route by UPDATE (renewal) message; After bgp router is received UPDATE message, carry out the filtration of strategy, the route that this locality is seen fit is announced to other BGP Peer (neighbours) again then; The final network reachability of realizing between each autonomous system.

With reference to figure 1, in bgp protocol, route be stored in the route selection information storehouse (Routing InformationBase, RIB) in; By introducing three logical levels, finally realize the storage and the announcement of route.Adj-RIBs-In: be used to preserve the route of receiving from each bgp peer; Loc-RIB: be used to preserve the route that local bgp peer allows use; Adj-RIBs-Out: be used to preserve the route that to announce to other bgp peers.With reference to figure 2, Adj-Ribs-In is associated with each bgp peer, is used to store the routing iinformation that receives from this peer-to-peer; Loc-Rib preserves those local routes that allow to use (comprising effective route of local configuration and the subclass of the Adj-Ribs-In that checks by input policing); Adj-Rib-Out is associated with each bgp peer, be used to store local selected to announce routing iinformation to the far-end bgp peer.Such design benefit is self-evident, yet has but drawn the problem excessive to memory consumption; Because Adj-Ribs-Out is associated with bgp peer, in other words, there are what Peer need receive this routing iinformation, will duplicate what part routes, and be saved in respectively in the corresponding PEER structure, calculate by every route 64 bytes, as N bar route, in the time of need mailing to M Peer, only Adj-Rib-Out just needs (M*N*64) byte.If it is a lot of to work as route, when Peer was also a lot of simultaneously, it is particularly outstanding that this problem will become.Obviously, bgp protocol is as gateway protocol between the territory, generally all operate on the core router, mutual each other route is inevitable a lot, the route of Internet net has surpassed 100,000 at present according to statistics, and this numeral also will continue to increase, and so big memory consumption will have a strong impact on cost performance of product.How reducing the consumption of routing table to internal memory efficiently, will be the problem that each network equipment supplier stands in the breach and will consider.

Summary of the invention

The present invention can effectively solve above-mentioned because the expansion of routing table causes the excessive problem of memory consumption, and a kind of solution of efficient saving bgp routing table memory consumption is provided.

Technology contents of the present invention: a kind of saving routing table memory consumption method of Border Gateway Protocol routing table, Loc-Rib as a public shared Buffer Pool, is preserved described routing iinformation;

Mapping relations for each bar establishing route in the Loc-Rib information bank and the Peer in the Adj-Rib-Out information bank;

By setting up the mapped bitmap of a Peer and global index, make that each Peer can a unique corresponding concrete index, certain bar route in the local route selection information of Loc-Rib storehouse, arbitration through a series of local policy, draw the conclusion that whether needs to the Peer announcement, when if desired routing iinformation being announced to certain corresponding Peer, need get ready on the Peer of this routing node association mapped bitmap this moment, purpose is to show that this route belongs to the part in the Adj-Rib-Out route selection information storehouse of Peer, hints that this route has sent to the Peer of appointment;

If the result of local policy arbitration need not to send to corresponding Peer, show that promptly this route has been cancelled, need then to determine that this route is whether in the Adj-Rib-Out information bank, promptly judge on the relevant position of this routing node Peer mapped bitmap whether once got ready, if exist then showed once and announced this route to Peer, route is no longer valid now, need to announce to Peer once more to cancel route with showing, and from local Adj-Rib-Out information bank the corresponding mapping relations of deletion, and the information of getting ready that empties described Peer correspondence gets final product.

In carrying out the route procedure for displaying, learn if desired this route whether announcement once give corresponding Peer, only need the mapped bitmap of scanning route and Peer, if the position of correspondence is got ready, show that then this route once announced to corresponding Peer.

Technique effect of the present invention: after receiving the UPDATE message that certain Peer sends, at first determine the preservation whether needs carry out local Adj-Ribs-In information bank according to strategy, the main purpose that preserve in Adj-Ribs-In route selection information storehouse is the realization for soft reboot, if the capability negotiation of Peer is found the opposite end and is supported route refresh mechanism, then this locality need not to carry out the preservation of Adj-Ribs-In information bank, thereby has saved the memory consumption of local Adj-Ribs-In information bank as much as possible.The Loc-Rib information bank as a public shared Buffer Pool, is preserved all existing routing iinformations; Set up the route in the Adj-Rib-Out information bank and the corresponding relation of a certain route in the Loc-Rib information bank, the Adj-Rib-Out information bank need not to safeguard that portion treats to send the copy of route again, how only need to know with the Loc-Rib information bank in the mapping relations of concrete routing node get final product, shared (three shared a routing iinformations in route selection information storehouse) of realization information realized saving to memory.And when showing, judge whether certain particular location is got ready on the Peer mapped bitmap of this route association get final product, reduced the process of once searching, also further improved the efficient of processing.The present invention is expanded to the influence of memory consumption thereby solve routing table by having abolished the linear relationship between routing table and the Peer number.

Description of drawings

Fig. 1 is the logical relation schematic diagram in each route selection information storehouse of Border Gateway Protocol of the present invention;

Fig. 2 is the route storage and the announcement flow chart of Border Gateway Protocol of the present invention;

Fig. 3 is an advertising of route process chart of the present invention;

Fig. 4 is that route of the present invention shows process chart.

Embodiment

Below with one particularly route be treated to example, the processing procedure that simple declaration is concrete once:

1) when receiving for the first time a route, the local new routing node of creating is preserved the specifying information of this route, and it is placed in the particular location in the local route selection information of Loc-Rib storehouse;

2) start the background process operation, be responsible for finishing the announcement processing procedure of this route to Peer;

3) after background job obtains scheduling, this route is handed over into to the arbitration decisions module, carry out the filtration of local policy, if passed through the decision-making of arbitration modules, show that then this route need announce to corresponding Peer, need get ready on the Peer of routing node mapped bitmap this moment, shows that this route is in the Adj-Rib-Out of corresponding Peer information bank;

4) if change has taken place in local policy subsequently, NMS user has been imported some new strategy, for example: disposed new route-map, perhaps received the message of cancelling, then all best routes in local route selection information storehouse delivered to arbitration modules successively and make a strategic decision again about this route from other Peer:

If a) result of this moment decision-making still for passing through, then judges the mapping relations of this route and Peer, whether the position of correspondence is got ready in the mapped bitmap, if get ready, shows that then this route announces to Peer before, need not to announce once more; Do not get ready else if, show that this route to announce to Peer before, need announcement again, then on the position of correspondence, get ready, and announce concrete route to Peer;

B) if the result of decision-making this moment, show and do not pass through, promptly this route is no longer valid, then need to judge whether once to send this advertising of route, can learn, if once sent this route before to Peer by the mapped bitmap of route and Peer to Peer, there is the information of getting ready in the particular locations of mapped bitmap, then need to show ground to this Peer send about this route cancel message, simultaneously, empty the information of getting ready accordingly on the mapped bitmap; If do not send this route to this Peer before, the particular locations on the mapped bitmap is not got information ready, then need not to do any subsequent treatment, need not send with showing and cancel route.

Further describe the basic procedure of route demonstration below:

Because need understanding certain bar route, the user whether once sent to corresponding Peer, for traditional realization, need be according to routing iinformation, in the Adj-Rib-Out of Peer correspondence route selection information storehouse, search once more, determined whether to exist the routing node of coupling,, illustrated that then this route once announced the Peer to correspondence if exist, otherwise then prompting was not announced this route to this Peer; By utilizing saving routing table memory consumption way provided by the invention, in carrying out the route procedure for displaying, learn if desired whether this route was once announced to corresponding Peer, only need the mapped bitmap of scanning route and Peer, if corresponding position is got ready, show that then this route once announced to corresponding Peer, otherwise, if point was not beaten in corresponding position, show then that this route was not announced to give corresponding Peer.

Claims

1. the saving routing table memory consumption method of a Border Gateway Protocol router is characterized in that: after this locality is received or self generated route, the Loc-Rib information bank as a public shared Buffer Pool, is preserved described routing iinformation;

Set up the mapped bitmap of a Peer and global index, make to be the mapping relations of described establishing route in the described Loc-Rib information bank and the Peer in the Adj-Rib-Out information bank by the unique corresponding concrete index of described each Peer energy;

The arbitration decisions module is carried out the filtration of local policy to described route, if described route has been passed through the decision-making of arbitration modules, then needs to give corresponding Peer with described advertising of route.

2. the saving routing table memory consumption method of Border Gateway Protocol router as claimed in claim 1, it is characterized in that: in the time of need giving corresponding Peer with described advertising of route, if do not get ready, then on this Peer mapped bitmap of described routing node, get ready at the Peer of described routing node mapped bitmap; Otherwise, on the Peer of described routing node mapped bitmap, do not get ready.

3. the saving routing table memory consumption method of Border Gateway Protocol router as claimed in claim 1, it is characterized in that: if do not arbitrate by local policy, judge on the relevant position of this routing node Peer mapped bitmap whether once got ready, if once beat point, then announce corresponding Peer and cancel described route, delete corresponding mapping relations from local Adj-Rib-Out information bank, and empty the information of getting ready of described Peer correspondence.

4. as the saving routing table memory consumption method of claim 2 or 3 described Border Gateway Protocol routers, it is characterized in that: in carrying out the route procedure for displaying, learn if desired whether this route was once announced to corresponding Peer, only need the mapped bitmap of scanning route and Peer, if corresponding position is got ready, show that then this route once announced to corresponding Peer.