Configuring Basic Bgp Functions; Establishing The Configuration Task - Huawei S6700 Series Configuration Manual

S6700 Series Ethernet Switches
Configuration Guide - IP Routing
Route Dampening
Route dampening is a method of solving the problem of route instability. Route instability is
reflected by route flapping. That is, a route in the routing table disappears and appears repeatedly.
If route flapping occurs, a routing protocol sends an Update message to its peers. After receiving
this Update message, the peers recalculate routes and modify their routing tables. Frequent route
flapping consumes a lot of bandwidth and CPU resources, even affecting the normal operation
of the network.
In most cases, BGP is applicable to complex networks where routes change frequently. To avoid
the impact of frequent route flapping, BGP suppresses unstable routes by using route dampening.
BGP Next Hop Delayed Response
BGP next hop delayed response can be used to speed up BGP route convergence and minimize
traffic loss when the upstream path of a PE connected to an RR changes.
BFD for BGP
The S6700 supports Bidirectional Forwarding Detection (BFD) in IPv4 to provide fast link
failure detection for BGP peer relationship.
BFD can rapidly detect faults on the links between BGP peers and report the faults to BGP, thus
implementing fast convergence of BGP routes.
BGP Security
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7.3 Configuring Basic BGP Functions

Configuring basic BGP functions is the prerequisite to building a BGP network.

7.3.1 Establishing the Configuration Task

Basic BGP functions must be configured first when you build up a BGP network.
Applicable Environment
BGP can be configured on a network to implement communication among ASs. This section
describes how to configure basic BGP functions.
Issue 01 (2012-03-15)
The S6700 authenticates BGP peers by using MD5 and Key-Chain, preventing packet fraud
or unauthorized packet modification.
Generalized TTL Security Mechanism (GTSM) checks TTL values to defend against
attacks. GTSM checks whether or not the TTL value in the IP header is within a specified
range, protecting the router against attacks and improving system security.
The number of routes received from the BGP peer is limited to prevent the resources from
exhausting. See 7.6.3 Configuring to Controll the Acceptment of BGP Routing
Information.
The lengths of AS paths on the inbound interface and the outbound interface are limited.
The excess packets are discarded. See
Routes.
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7.4.7 Configuring AS_Path Attributes for
7 BGP Configuration
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