H3C Technologies H3C S10500 Series Switches - Manual (Page 348)

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To do… Use the command… Remarks
Configure to carry only the public
AS number in updates sent to a
peer or peer group
peer { ipv6-group-name |
ipv6-address } public-as-only
Optional
By default, IPv6 BGP updates carry
a private AS number.
Substitute the local AS number for
the AS number of an IPv6 peer or
peer group identified in the
AS_PATH attribute
peer { ipv6-group-name |
ipv6-address } substitute-as Optional
Not substituted by default
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 massage is sent, nor holdtime is
checked.
• IPv6 BGP connection soft reset
After modifying a route selection policy, you must 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, you must 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 configuring IPv6 BGP timers, complete the following tasks:
• Enable IPv6
• Configure IPv6 BGP basic functions
Configuring IPv6 BGP timers
Follow these steps to configure IPv6 BGP timers:
To do… Use the command… Remarks
Enter system view system-view —
Enter BGP view bgp as-number —