|
When policies such as access lists or attributes are changed, the change takes effect immediately, and the next time that a prefix or path is advertised or received, the new policy is used.
It can take a long time for the policy to be applied to all networks.
Trigger an update to ensure that the policy is immediately applied to all affected prefixes and paths.
Ways to trigger an update:
- Hard reset : BGP session will go down and be reestablished: traffic will be affected.
Command.
# exe router clear bgp [ip|all] <neighbor_ip>
- Soft reset.
Command.
# exe router clear bgp ip <neighbor_ip> soft [in|out]
Out: Resend all BGP information to the neighbor without resetting the connection.
Recommended when changing outbound policy.
In: Soft reconfiguration inbound must be enable first.
It will store all received prefixes from the neighbor in a table in case the inbound policy is changed.
Consume more memory.
- Route refresh.
Command.
# exe router clear bgp ip <neighbor_ip> [in|out]
- Route refresh capability must have been negotiated at the BGP session setup (in BGP OPEN message):
vdom2 # get router info bgp neighbors 10.200.2.2 | grep refresh
Route refresh: advertised and received (old and new)
Route refresh request: received 0, sent 3
|
