H3C Technologies H3C S12500 Series Switches - Manual (Page 383)

367
Tuning and optimizing IPv6 BGP networks
This section describes configurations of IPv6 BGP timers, IPv6 BGP connection soft reset, and the
maximum number of load balanced routes.
• IPv6 BGP timers
After establishing an IPv6 BGP connection, two routers send keepalive messages periodically to
each other to maintain the connection. If a router receives no keepalive message from the peer
after the holdtime elapses, it tears down the connection.
When establishing an IPv6 BGP connection, the two parties compare their holdtimes, taking the
shorter one as the common holdtime. If the holdtime is 0, neither keepalive message is sent, nor
holdtime is checked.
• IPv6 BGP connection soft reset
After modifying a route selection policy, reset IPv6 BGP connections to make the new one take
effect. The current IPv6 BGP implementation supports the route-refresh feature that enables
dynamic route refresh without needing to disconnect IPv6 BGP links.
After this feature is enabled on all IPv6 BGP routers, a router that wants to apply a new route
selection policy advertises a route-refresh message to its peers, which then send their routing
information to the router. After receiving the routing information, the router can perform dynamic
route update by using the new policy without tearing down connections.
If a peer not supporting route-refresh exists in the network, configure the peer keep-all-routes
command to save all routes from the peer. When the routing policy is changed, the system will
update the IPv6 BGP routing table and apply the new policy.
Configuration prerequisites
Before you configure IPv6 BGP timers, complete the following tasks:
• Enable IPv6.
• Configure IPv6 BGP basic functions.
Configuring IPv6 BGP timers
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view. bgp as-number N/A