HP VPN Firewall Appliances Network Management Configuration Guide
496
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:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter BGP view or BGP-VPN instance
view.
bgp as-number N/A
3. Configure BGP to ignore the first AS
number of EBGP route updates.
ignore-first-as
By default, BGP checks the 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.
Follow these guidelines when you configure the BGP keepalive interval and holdtime:
• The maximum keepalive interval should be one third of the holdtime and no less than one second.
The holdtime is no less than three seconds unless it is set to 0.
• 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:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A