Displaying And Maintaining Mce; Resetting Bgp Connections - H3C S5800 Series Configuration Manual

Normally, BGP checks routing loops by examining AS numbers. If EBGP is used between the
MCE and a site, when the MCE advertises its routing information with its AS number to the site
and then receives routing update information from the site, the route update message will carry
the AS number of the MCE, making the MCE unable to receive this route update message. In this
case, to make the MCE to receive route updates normally, you need to configure the MCE to allow
routing loops.
In standard BGP/OSPF route redistribution, when a route is redistributed into OSPF from BGP on
the MCE, the route's original OSPF attribute cannot be restored, making the route unable to be
distinguished from routes redistributed from other domains. To distinguish routes of different
OSPF domains, you need to enable a route to carry the OSPF domain ID when the route is
redistributed from OSPF into BGP on the peer PE. Thus, the domain ID of an OSPF process is
carried in a route generated by the process. When the OSPF route is redistributed into BGP, the
domain ID is added to the BGP VPN route and is transmitted over the network as the extended
community attribute of BGP.
After you configure a BGP VPN instance, the BGP route exchange in the VPN instance is the
same as the common BGP's. For BGP configuration details, see BGP Configuration in the Layer 3
- IP Routing Configuration Guide.

Displaying and Maintaining MCE

Resetting BGP Connections

When BGP configuration changes, you can use the soft reset function or reset BGP connections to
make new configurations take effect. Soft reset requires that BGP peers have route refreshment
capability (supporting Route-Refresh messages).
To do...
Perform a soft reset of the BGP
connections in a specified VPN
instance
Reset BGP connections of a VPN
instance
Use the command...
refresh bgp vpn-instance
vpn-instance-name { ip-address |
all | external | group
group-name } { export | import }
reset bgp vpn-instance
vpn-instance-name { as-number |
ip-address | all | external | group
group-name }
14-21
Remarks
Available in user view
Available in user view