receives a route-refresh request, neighbor sends the updates. This route refresh is initiated based on a delay
configured for each BMP server. This is called route refresh delay. When there are multiple neighbors to be
monitored, each neighbor is set a refresh delay based upon the BMP server they are enabled for. Once all the
BGP neighbors have sent the updates in response to the refresh requests, the tables will be up to date in the
BMP Server. If a neighbor establishes connection after BMP monitoring has begun, it does not require a
route-refresh request. All received routes from that neighbor is sent to BMP servers.
It is advantageous to batch up refresh requests to BGP peers, if several BMP servers are activated in quick
succession. Use the bmp server initial-refresh-delay command to configure a delay in triggering the refresh
mechanism when the first BMP server comes up. If other BMP servers come online within this time-frame,
only one set of refresh requests is sent to the BGP peers. You can also configure the bmp server
initial-refresh-delay skip command to skip all refresh requests from BGP speakers and just monitor all
incoming messages from the peers.
In a client-server configuration, it is recommended that the resource load of the devices be kept minimal and
adding excessive network traffic must be avoided. In the BMP configuration, you can configure various delay
timers on the BMP server to avoid flapping during connection between the server and client.
How to Implement BGP
Enabling BGP Routing
Perform this task to enable BGP routing and establish a BGP routing process. Configuring BGP neighbors is
included as part of enabling BGP routing.
At least one neighbor and at least one address family must be configured to enable BGP routing. At least
one neighbor with both a remote AS and an address family must be configured globally using the address
family and remote as commands.
Note
Before You Begin
BGP must be able to obtain a router identifier (for example, a configured loopback address). At least, one
address family must be configured in the BGP router configuration and the same address family must also be
configured under the neighbor.
If the neighbor is configured as an external BGP (eBGP) peer, you must configure an inbound and outbound
route policy on the neighbor using the route-policy command.
Note
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
79
Implementing BGP
How to Implement BGP
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