Allied Telesis C613-16164-00 REV E manual Route Limits, Configuring static route limits

Route Limits

Route Limits

In multi-VRF network environment, it may be disastrous if one VRF injects too many routes and fills up the hardware forwarding table (FIB) on a device which can affect other VRFs (as well as the global VRF).

In software version 5.4.2 and later, it is possible to mitigate this risk, as route limits can now be configured on a per VRF basis.

Existing AW+ commands max-static-routes and max-fib-routes have been extended in 5.4.2 to allow configurable static and dynamic route limits on a per VRF instance basis.

Note: The command max-fib-routes only counts dynamic routes (not including static and connected routes).

Note: By default, there is no preset allocation of the number of route table entries available to each VRF instance. When static and/or dynamic VRF instances are configured (without setting limits via the commands max-static-routes and max-fib-routes), the number of route table entries available to each VRF instance are not automatically reserved.

Configuring static route limits

AW+ supports the ability to limit static routes via the max-static-routes command in the global VRF domain, with a default maximum limit of 1000 (routes). This same AW+ command is now also able to be applied on a per VRF basis.

Static route limits can be applied as part of VRF Configuration Mode via the command:

awplus(vrf-config)#max-static-routes <1-1000>

The following example shows how to configure a limit of 200 static routes, applied to VRF red:

awplus(config)# ip vrf red

awplus(config-vrf)#max-static-routes 200

Note: Static routes limits are applied before adding routes to the RIB. Rejected static routes will not be in the running config.

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