Tuning And Optimizing Bgp Networks; Configuring The Bgp Keepalive Interval And Holdtime - HPE 5800 Series Configuration Manual

For some network applications, a BGP router does not add its own AS number to the AS_PATH
attribute. In this case, you must configure the ignore-first-as command on the EBGP peer to ignore
the first AS number of EBGP route updates.
To ignore the first AS number of EBGP route updates:
Step
Enter system view.
1.
Enter BGP view or
2.
BGP-VPN instance view.
Configure BGP to ignore the
3.
first AS number of EBGP
route updates.

Tuning and optimizing BGP networks

Configuring the BGP keepalive interval and holdtime

After establishing a BGP session, two routers send keepalive messages at the specified keepalive
interval to each other to keep the session.
If a router receives no keepalive or update message from the peer within the holdtime, it tears down
the session.
You can configure the keepalive interval and holdtime globally or for a specific peer or peer group.
The intervals configured for the specified peer or peer group takes higher priority. The actual
keepalive interval and holdtime depend on the following cases:
•
If the holdtime settings on the local and peer routers are different, the smaller one is used.
•
If the configured keepalive interval is 0 and the negotiated holdtime is not 0, the actual
keepalive interval equals one-third of the holdtime.
•
If the configured keepalive interval is not 0, the actual keepalive interval is the smaller one
between one third of the holdtime and the keepalive interval.
When you configure BGP keepalive interval and holdtime, follow these guidelines:
•
The intervals set with the peer timer command are preferred to those set with the timer
command.
•
If the router has established a BGP session with a peer, you must reset the BGP session to
validate the new set timers.
•
The timer command takes effect for only new BGP sessions.
•
After you set new intervals with the peer timer command, the existing BGP session is closed at
once, and a new session to the peer is negotiated by using the configured holdtime.
To configure BGP keepalive interval and holdtime:
Step
Enter system view.
1.
Command
system-view
bgp as-number
ignore-first-as
Command
system-view
203
Remarks
N/A
N/A
By default, BGP checks the first
AS number of EBGP route
updates.
Remarks
N/A