H3C Technologies H3C S12500 Series Switches - Manual (Page 257)

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Step Command Remarks
3. Enable the logging of session
state changes globally.
log-peer-change
Optional.
Enabled by default.
4. Enter BGP-VPN instance view. ipv4-family vpn-instance
vpn-instance-name
Optional.
5. Enable the logging of session
state changes for a peer or
peer group.
peer { group-name | ip-address }
log-change Optional.
Enabled by default.
Configuring BFD for BGP
BGP maintains neighbor relationships based on the keepalive timer and holdtime timer, which are set in
seconds. BGP defines that the holdtime interval must be at least three times the keepalive interval. This
mechanism makes link failure detection rather slow; once a failure occurs on a high-speed link, a large
quantity of packets will be dropped. BFD is introduced to solve this problem. It detects links between
neighbors quickly to reduce convergence time upon link failures.
After a link failure occurs, BFD might detect the failure before the system performs GR. As a result, GR will
fail. If GR capability is enabled for BGP, use BFD with caution. If GR and BFD are both enabled, do not
disable BFD during a GR process; otherwise, GR might fail. For BFD configuration, see High Availability
Configuration Guide. Before configuring BFD for BGP, you must enable BGP.
To enable BFD for a BGP peer:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Enable BFD for the specified
BGP peer.
peer ip-address bfd
By default, no BGP peer is
enabled.
Displaying and maintaining BGP
Displaying BGP
Task Command Remarks
Display peer group information.
display bgp group [ group-name ] [ | { begin |
exclude | include } regular-expression ]
Available in any view.
Display advertised BGP routing
information. display bgp network [ | { begin | exclude |
include } regular-expression ]
Available in any view.