Users Guide

View dampened paths
OS10# show ip bgp dampened-paths
BGP local router ID is 80.1.1.1
Status codes: s suppressed, S stale, d dampened, h history, * valid, > best
Origin codes: i - IGP, e - EGP, ? - incomplete
Network From Reuse Path
d* 3.1.2.0/24 80.1.1.2 00:00:12 800 9 8 i
d* 3.1.3.0/24 80.1.1.2 00:00:12 800 9 8 i
d* 3.1.4.0/24 80.1.1.2 00:00:12 800 9 8 i
d* 3.1.5.0/24 80.1.1.2 00:00:12 800 9 8 i
d* 3.1.6.0/24 80.1.1.2 00:00:12 800 9 8 i
Total number of prefixes: 5
Timers
To adjust the routing timers for all neighbors, congure the timer values using the timers command. If both the peers negotiate with
dierent keepalive and hold time values, the nal hold time value is the lowest values received. The new keepalive value is one-third of the
accepted hold time value.
• Congure timer values for all neighbors in ROUTER-NEIGHBOR mode.
timers keepalive holdtime
– keepalive — Time interval in seconds, between keepalive messages sent to the neighbor routers (1 to 65535, default 60).
– holdtime — Time interval in seconds, between the last keepalive message and declaring the router dead (3 to 65535, default
180).
View nondefault values
OS10# show running-configuration
...
neighbor 32.1.1.2
remote-as 103
timers 61 181
no shutdown
Neighbor soft-reconguration
BGP soft-reconguration allows for fast and easy route changes. Changing routing policies requires a reset of BGP sessions or the TCP
connection, for the policies to take eect.
Resets cause undue interruption to trac due to the hard reset of the BGP cache, and the time it takes to re-establish the session. BGP
soft-reconguration allows for policies to apply to a session without clearing the BGP session. You can perform a soft-reconguration on a
per-neighbor basis, either inbound or outbound. BGP soft-reconguration clears the policies without resetting the TCP connection. After
conguring soft-reconguration, use clear ip bgp to make the neighbor use soft reconguration.
When you enable soft-reconguration for a neighbor and you execute the clear ip bgp soft in command, the update database
stored in the router replays and updates are re-evaluated. With this command, the replay and update process triggers only if a route-refresh
request is not negotiated with the peer. If the request is negotiated after using the
clear ip bgp soft in command, BGP sends a
route-refresh request to the neighbor and receives all the peer’s updates.
To use soft reconguration, or soft reset without preconguration, both BGP peers must support the soft route refresh capability. The soft
route refresh advertises in the OPEN message sent when the peers establish a TCP session. To determine whether a BGP router supports
this capability, use the show ip bgp neighbors command. If a router supports the route refresh capability, the Received route
refresh capability from peer
message displays.
Layer 3
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