Filter
Top Products
DES-7200 Configuration Guide Chapter 6 BGP
Configuration
6-29
mode.
Use the bgp nexthop trigger enable command to restore the setting to the
default value.
The bgp nexthop trigger enable command and the bgp scan-time command
control the same timer. When the timing scanning mechanism is enabled, the
time of larger than 60 seconds set by the the bgp nexthop trigger enable
command does not take effect because the timing scanning mechanism is always
activated before the delay time.
Caution
In an unstable network (the next hop changes frequently), especially there are a
lot number of routes, this function carries out unnecessary route calculation and
thus aggravates consumption of CPU resource. In this case, it is recommended
to disable the BGP next hop trigger update mechanism.
6.20 Configuring BGP GR
GR (Graceful Restart) can ensure continous data forwarding duing the reset of
the BGP protocol.
6.20.1 Working Mechanism of GR
1 Standard
RFC4724: Graceful Restart Mechanism for BGP, which is represented by BGP
GR later.
2 Working mechanism
RFC4724 is a standard GR protocol that IETF especially defines for the BGP
protocol. This document outlines the principles of BGP GR, including:
Graceful Restart Capability is added to the OPEN message of the BGP protocol,
indicating that the BGP supports GR. The GR capability is negotiated by
neighbors during the initiation of BGP connection.
GR Restarter and GR Helper. GR Restarter refers to the router restarting the BGP
protocol, which can ensure continuous route forwarding when the route control
panel fails. GR Helper is the BGP neighbor of the GR Restarter that assists the
GR Restarter to do BGP GR for continous forwarding in the overall network.
In the update message, EOR (End-of-RIB) is added to indicate that the route
message update is completed.
The following ffigure illustrates the process of BGR GR.