Tuning And Optimizing Mbgp Networks; Prerequisites; Configuring Mbgp Soft Reset - HP 4800G Series Configuration Manual

Follow these steps to configure the AS-PATH attribute:
Enter system view
Enter BGP view
Enter IPv4 MBGP address family view
Configure
the
AS_PATH
attribute

Tuning and Optimizing MBGP Networks

This task involves resetting MBGP connections and configuring load balancing.

Prerequisites

You need to configure BGP basic functions before configuring this task.

Configuring MBGP Soft Reset

After modifying a route selection policy, you have to reset MBGP connections to make it take effect,
causing short time disconnections.
After the route-refresh capability is enabled on all MBGP routers in a network, when a route selection
policy is modified on a router, the local router can perform dynamic route updates without tearing down
MBGP connections.
If the peer does not support route-refresh, you can save all route updates from the peer. When the route
selection policy changes, you can refresh the MBGP routing table and apply the new policy without
tearing down MBGP connections.
Soft reset through route-refresh
If the peer is enabled with route-refresh, when the MBGP route selection policy is modified on a router,
the router advertises a route-refresh message to its MBGP peers, which resend their routing information
to the router after receiving the message. Therefore, the local router can perform dynamic route update
and apply the new policy without tearing down MBGP connections.
Follow these steps to configure MBGP soft reset through route-refresh:
To do...
Specify the maximum
number of times the
local AS number can
appear in routes from
the peer/peer group
Disable BGP from
considering the
AS_PATH during best
route selection
Configure updates to a
peer/peer group to not
keep private AS
numbers
Use the command...
system-view
bgp as-number
ipv4-family multicast
peer { group-name |
ip-address } allow-as-loop
[ number ]
bestroute as-path-neglect
peer { group-name |
ip-address } public-as-only
1-10
Remarks
—
—
—
Optional
By default, the local AS
number can not appear
in routes from a
peer/peer group.
Optional
By default, BGP
considers AS_PATH
during best route
selection.
Optional
By default, BGP updates
carry private AS
numbers.