User Manual

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Users Manual of XGS-6350-24X4C
new soft reconfiguration is used to send the outgoing update to the neighbor, it is called outgoing soft
reconfiguration. After the incoming soft reconfiguration is run, new input policies validates. After the outgoing
soft reconfiguration is run, the new local output policy validates without resetting BGP session.
In order to generate the incoming update without resetting BGP session, the router of the local BGP session
should restore the received incoming update without modification. Whether the incoming update is received
or declined by the current incoming policy is not in the consideration. In this case, the memory will be badly
occupied. The outgoing reconfiguration has no extra memory cost, so it is always valid. You can trigger the
outgoing soft reconfiguration on the other side of the BGP session to validate the new local incoming policy.
To permit the incoming soft reconfiguration, you need to configure BGP to restore all received routing update.
The outgoing soft reconfiguration does not require pre-configuration.
Run the following command to configure BGP soft reconfiguration:
Command Purpose
Neighbor { ip-address }
soft-reconfiguration [inbound]
Configures BGP soft reconfiguration.
45.4.2.1.4 Resetting BGP Connection
Once two routers are defined as BGP neighbors, they will create a BGP connection and exchange route
choice information. If the BGP routing policy is modified afterwards, or if other configuration is changed, you
must reset the BGP connection to validate the changed configuration. Run one of the following commands to
reset the BGP connection.
Command Purpose
clear ip bgp * Resets all BGP connections.
clear ip bgp address
Resets a special BGP connection.
45.4.2.1.5 Configuring Synchronization Between BGP and IGPs
If an AS sends information at the third AS through your AS, the internal routing state of your AS must be the
same as the routing information that the AS broadcasts to other ASs. For example, before all routers in your
AS learn the routes through IGP, your AS may receive routing information from your BGP that some routers
cannot route. The synchronization between BGP and IGP is that the BGP does not broadcast the routing
information until all IGP routers in the AS learn the routing information. The synchronization is activated by
default.
In some cases, you need not to perform the synchronization between BGP and IGP. If other ASs are not
allowed to send data through your AS, or if all routers in your AS run BGP, the synchronization will be
cancelled. After the synchronization is cancelled, your IGP can carry a few routes and BGP will aggregate
more rapidly.
Run the following command to cancel the synchronization:
Command Purpose
no synchronization
Cancel the synchronization between
BGP and IGP.