HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 3 - IP Routing Confi - Page 168

Enabling logging of peer state changes, Configuring BFD for BGP, Displaying and maintaining BGP

Page 168 highlights

Enabling logging of peer state changes Step 1. Enter system view. 2. Enter BGP view. 3. Enable the logging of peer state changes globally. 4. Enable the logging of peer state changes for a peer or peer group. Command system-view bgp as-number log-peer-change peer { group-name | ip-address } log-change Remarks N/A N/A Optional. Enabled by default. 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 slows down link failure detection; 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 may 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 may fail. For BFD configuration, see High Availability Configuration Guide. IMPORTANT: Before configuring BFD for BGP, you must enable BGP. To enable BFD for a BGP peer: Step 1. Enter system view. 2. Enter BGP view. 3. Enable BFD for the specified BGP peer. Command system-view bgp as-number peer ip-address bfd Remarks N/A N/A Not enabled for any BGP peer by default. Displaying and maintaining BGP Displaying BGP Task Display peer group information. Command Remarks display bgp group [ group-name ] [ | { begin | exclude Available in | include } regular-expression ] any view 158

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158
Enabling logging of peer state changes
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view.
bgp
as-number
N/A
3.
Enable the logging of peer
state changes globally.
log-peer-change
Optional.
Enabled by default.
4.
Enable the logging of peer
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
slows down link failure detection; 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 may 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 may fail. For BFD configuration, see
High Availability
Configuration Guide
.
IMPORTANT:
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.
bgp
as-number
N/A
3.
Enable BFD for the specified
BGP peer.
peer
ip-address
bfd
Not enabled for any BGP peer by
default.
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