Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

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Configuring BGP for Overload Conditions
You can specify how you want BGP to behave when it is running out of memory in an
overload condition. You can have BGP either shut itself down or continue running; in the
latter case, BGP performance might be altered because of the lack of resources.
overload shutdown
•
Use to shut down BGP if it runs out of memory.
•
The default behavior is for BGP to transition from the Up state to the Overload state
and continue running.
•
This command takes effect immediately.
•
Example
host1(config-router)# overload shutdown
•
Use the no version to restore the default behavior.
•
See overload shutdown.
The following partial outputs show how the BGP state is indicated by the show ip bgp
summary command:
host1# show ip bgp summary
Local router ID 10.1.0.1, local AS 1
Administrative state is Start
Operational state is Overload
Shutdown in overload state is disabled
Default local preference is 100
...
host1#
show ip bgp summary
Local router ID 10.1.0.1, local AS 1
Administrative state is Start
Operational state is Down due to transition from Overload state
Shutdown in overload state is enabled
Default local preference is 100
...
Enabling Route Storage in Adj-RIBs-Out Tables
By default, a BGP speaker does not store a copy of each route it sends to a BGP peer in
the Adj-RIBs-Out table for that peer. However, you can force BGP to store a copy of
routes in the Adj-RIBs-Out table for a particular peer or peer group by enabling that
Adj-RIBs-Out table (“ enabling rib-out” ) with the
no neighbor rib-out disable command.
Alternatively, you can use the no rib-out disable command to affect all BGP peers. The
details of route storage vary between peers and peer groups.
For peers, BGP stores a single bit with each route in the table to indicate whether it has
previously advertised the route to the peer, enabling the avoidance of spurious
withdrawals. The full set of attributes for each route is not stored in the peer Adj-RIBs-Out
table.
After enabling rib-out for a peer, you can issue the show ip bgp neighbors
advertised-routes command to display the routes that have been advertised to the peer.
The attributes displayed for the routes are those from the local routing table, not those
41 Copyright © 2010, Juniper Networks, Inc.
Chapter 1: Configuring BGP Routing