3Com 10014299 manual Display Route Flap Information

	Configuring BGP 465
Table 547 Configure Route Dampening
Operation	Command
Put BGP route attenuation in effect or	dampening [ half-life-reachable
modify BGP route attenuation parameter	half-life-unreachable reuse suppress
	ceiling ] [ route-policypolicy-name
	]
Clear route routing dampening	reset dampening [ network-address[
information and de-suppress the	mask ] ]
suppressed route
Disable the route dampening	undo dampening

By default, route dampening is disabled.

2Display route flap information.

Perform the following configurations in system view.

Table 548 Display Route Flap Information

Operation	Command
Display BGP dampened routes	display bgp routing-table dampened
Display flap information of all routes	display bgp routing-table
	flap-information
Display the route flap statistics of routes	display bgp routing-table
with AS path comply with regular	flap-information regular-expression
expression	as-regular-expression
Reset BGP flap information matching AS	reset bgp flap-information
path regular expression	regular-expression [
	as-regular-expression ]
Display the route flap statistics of routes	display bgp routing-table
that passed AS filter-list	flap-information acl
	[aspath-list-number ]
Clear BGP flap information matching the	reset bgp flap-information acl
specified filter list	[aspath-list-number ]
Display the route flap statistics of routes	display bgp routing-table
with designated destination address	flap-information network-address
	mask [ longer-match ]
Clear the route flap statistics of routes	reset bgp flap-information
with designated destination address	network-address
Clear the route flap statistics of routes	reset bgp network-address
received from the specified peer.	flap-information

Configuring BGP protocol prescribes that a BGP router does not advertise the destination Synchronization of BGP known through internal BGP peers to external peers unless the destination can be

and IGP known also through IGP. If a router can know the destination through IGP, then the route can be distributed in the AS because an internal connection has been ensured.

One major task of the BGP protocol is to distribute the network reachable information of the local AS to other ASs. Therefore, BGP needs to distribute the route information by synchronization with IGP (such as RIP and OSPF), Synchronization means that BGP cannot distribute transition information to other ASs until IGP broadcasts the route information successfully within its AS. That is to say, before a router receives an updated destination information from an IBGP