conditional static route

illusion_rox · ‎08-05-2007

hi can someone tell me how to install a static route based on certain condition ? and remove it if that condition is no more met ? i know that there is a way of doing it but i m not able to remember how so some one help me out on this

thanks

Harold Ritter · ‎08-05-2007

Ovais,

What you are looking for is reliable static route feature. Please refer to the following URL for more information:

http://www.cisco.com/en/US/products/sw/iosswrel/ps5413/products_feature_guide09186a00801d862d.html

Hope this helps,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
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Cuauhtémoc, Juárez
Ciudad de México, 06600
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Edison Ortiz · ‎08-05-2007

ip route [destination ip] [destination subnet] [gateway] [track]

You need to create a track that if valid the ip route will be installed in the RIB.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cr/hirp_r/rte_pih.htm#wp1134595

illusion_rox · ‎08-05-2007

ok i got it but i m not able to understand how the track object works can u explain me with a simple example ?

thanks

royalblues · ‎08-05-2007

It uses the cisco IP SLA feature

We generally configure a IP SLA monitor that uses the ICMPecho functionality and tracks the reachability of destination specified.

We then bind this to the static route as Edison quoted above. When the destination specified is not reachable then that route is flushed from the table. This technique helps as you can have the IP SLA destination multiple hops away and still flush out the static route entry for a failure not with the immediate nexthop.

HTH

Narayan

Edison Ortiz · ‎08-05-2007

Let's say if you wanted to install a default route based on the S0/0 being up.

track 1 interface s0/0 line-protocol

ip route 0.0.0.0 0.0.0.0 [gateway] track 1

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cr/hiap_r/apl_t1h.htm#wp1129487