H3C Technologies H3C S12500 Series Switches - Manual (Page 250)

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Step Command Remarks
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Forbid session establishment
with a peer or peer group. peer { group-name | ip-address }
ignore Optional.
Not forbidden by default.
Configuring BGP soft-reset
After you modify the route selection policy, you must reset BGP sessions to apply the new policy. The reset
operation tears down and re-establishes BGP sessions.
To avoid tearing down BGP sessions, you can use one of the following soft-reset methods to apply the
new policy.
The following soft-reset methods are available:
• Automatic soft-reset—The BGP router advertises a route-refresh message to the specified peer and
the peer resends its routing information to the router. After receiving the routing information, the
router filters the routing information by using the new policy.
This method requires that both the local router and the peer support route refresh.
• Manual soft-reset—Uses the peer keep-all-routes command to save all route updates from the
specified peer. After modifying the route selection policy, use the refresh bgp command to filter
routing information by using the new policy.
This method does not require that the local router and the peer support route refresh but it uses
more memory resources to save routes.
Configuring automatic soft-reset
After route refresh is enabled for peers and a policy is modified, the router advertises a route-refresh
message to the peers, which then resend their routing information to the router. After receiving the routing
information, the router performs dynamic route update by using the new policy.
To enable BGP route refresh for a peer or peer group:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Enable BGP route refresh for a
peer or peer group.
peer { group-name | ip-address }
capability-advertise route-refresh Optional.
Enabled by default.