Router BGP by setting up a peer sessions pair with continuous function. Compared to the other important advantage of TCP that BGP sends update messages and maintain the use of peer to peer sessions. As a result, these sessions are not link health directly to the integrity of the concept of adjacent router but also proposes additional measures. If the router is inaccessible or unresponsive, watching the sessions is reduced, the course received the link will be removed from the BGP table and then inform other routers.
Cette perte de la connexion en raison de la défaillance ou de panne de courant peut provoquer des routeurs et transmission au cours d'une session de lien ou simplement entraîner BGP informations datagrammes ignorés les problèmes de congestion. L'explosion de l'Internet au cours des années, expérience de changements d'état des routeur BGP/EGP voisin deviennent encore plus problématique. Ceci est habituellement causée par plusieurs fois pour redémarrer le routeur ou liaisons intermittentes. Récemment, la cause de ce problème est que le routeur est le message de mise à jour d'overwhelemd ne conserve pas de sessions par les pairs. Mots inventé pour décrire cette annonces dupliquées et Itinéraire supprimé est "flap itinéraire" tête-bashing "routeur. Par conséquent, ces messages avec les routeurs voisins (et très probablement en aval de routeurs deux ou trois liens) overwhelemd recalcule le chemin et passer tout son temps. L'effet est que le service de routeur est dégradé jusqu'au retour de la stabilité. Il peut même cause le routeur commence « volets », aussi bien que plus récents que ce routeur est capable de gérer, créer des pannes en cascade. Travail considérable de recherche et de développement menée par les nombreuses entreprises avec routeur production zèle peut gérer ces mises à jour et nombreux fournisseurs de services à élaborer des politiques visant à réduire pour réduire les volets ou de se protéger contre le rabat « retenue », dans un intervalle de lambeau de peau répétées de la taille de la table de routage pour la route.Border Gateway Protocol (BGP) is a distance vector protocol family. However, unlike most routing protocols, BGP view is different and the path of autonomous systems (ass). As broadly defined as a collection of routers under a common management. For example, Primenet is the MCI is another, AT&T the third, and so on. These asses have their own AS numbers, BGP used in the Exchange. Primenet's number (ASN) as 3549,MCI is 3,561, and so on.
Router BGP capability by setting up a peer to peer sessions with continuous. Compared to other important advantage of TCP protocol BGP sends update messages and maintain the use of peer to peer sessions. Therefore, these sessions are not health link directly to the integrity of the adjacent router concept but also offers additional measures. If the router is inaccessible or has stopped responding, watching sessions will be reduced, the course received the link will be removed from the BGP table and subsequently inform other routers.
This loss of connection due to failure or loss of power can cause routers and transmission over a link session or simply result in BGP information datagrams discarded congestion problems. The explosion of the Internet in the past years, experience of the router BGP/EGP neighbor state changes become even more problematic. This is usually caused by several times to restart the router or intermittent links. Recently, the cause of this problem is the router is overwhelemd update message does not maintain peer sessions. Words coined to describe this duplicate ads and deleted route is "route flap" head-bashing "router. Consequently, these messages with neighboring routers (and quite probably downstream routers two or three links) overwhelemd recalculates the path and spending all of his time. The effect of this is the router service is degraded until stability returns. It may even cause the router begins "flap", as well as newer than this router is able to handle, create cascading failures. Considerable research and development work being done by the many companies with zeal production router can handle these updates and many service providers to develop policies to reduce to reduce flaps or protect themselves from the flap "restraint" in a given interval of repeated skin flap of the size of the routing table for the route.
BGP route contains only a few pieces of information. First is that the network describes the route. Second, as the path needed to reach the destination. Third, the origin of the route (or EBGP external BGP, internal BGP IBGP, another or IGP Interior Gateway Protocol, or is incomplete.) IV, adverts on the router ID of the router and finally, BGP next-hop address.
BGP provides a simple, yet effective method of cycle detection. Simply put, the route was learned AS the router check the path as a number. If this number show up anywhere in the path, a route becomes unavailable, it will be discarded.
There are also several weights and to assist directly in the process of selecting metrics associated with BGP routing. Fucked for the first time called "weight", as only by routers, set it to use. This weight is not propegated to other routers. The second is "local prefference" value. This is belonging to the separate save propegated to all router our website support is the last value of "metric" or "exit Descriminator" (MED). Pill signed to EBGP neighbors and was used to suggest the best route to AS. Eastern Mediterranean is reset route readvertized to third.
BGP direct selection process is straight forward.
- If you are unable to access the next hop is not considering it
- More BGP administrative weight are considered first
- If your router has the same weight, taking into account the higher the priority routes with local
- If the route has the same local preferences, preferred from the local router's routing
- If there is no route origin, prefer a short autonomous system paths
- If all the paths have the same autonomous system path length, prefer minimal source code (IGP<EGP< is not complete)
- If the source code is the same for all paths out of the same autonomous system, more like multi exit discriminator (MED) minimum hop paths. Missing metric is considered zero
- If the medicine is the same preferred outside path through internal
- If the IGP synchronization is disabled, only the internal path still prefer the path of the nearest neighbor.
- Like route IP address with the lowest BGP router ID value
router bgp 3549
neighbor 1.2.3.4 remote-as 3549
neighbor 2.3.4.5 remote-as 380
Network 1.0.0.0
Class a network 1.0.0.0 in iBGP routing tables, and become qualified eBGP peer, with source code, "IGP" ads. Under normal circumstances, this is the results of the other protocols into BGP redistribution of information learned by IGP redistribution among these network-related loss and can lead to routing loops preferred method of advertising BGP network.
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