F3215-HP Load Balancing Module Network Management Configuration Guide-6PW101

274
Ste
p
Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view.
bgp as-number N/A
3. Configure BGP to remove
private AS numbers from the
AS_PATH attribute of updates
to a peer or peer group.
peer { group-name | ip-address }
public-as-only
By default, BGP updates carry
private AS numbers.
6. Ignoring the first AS number of EBGP route updates
Typically, BGP checks the AS_PATH attribute of a route update received from a peer. If the first AS number
is not that of the BGP peer, the BGP router discards the route update.
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. 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.