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routesload-balancingcisco

On Cisco routers, is it possible to have equal cost multipath static routes ?

On Cisco routers, is it possible to have equal cost multipath static routes ?

If so, how ?

Thanks.

Solution

  • Yes. IOS router with will load share between static/default routes. Just enter two static routes to the same destination, pointing to different next-hops:

    ip route 10.3.1.1 255.255.255.255 10.0.0.2
    ip route 10.3.1.1 255.255.255.255 10.0.0.6

    (these nex-hops of course should know a way to the destination address/net)
    Load sharing behavior is dependent on packet switching method used for some particular flow.

    With IOS fast switching - you can load-share only per-destination (ip-src - ip-dst pair).
    With CEF you can use two load sharing algorythms - per-packet and per-destination.

    Use this global config command to turn CEF on:

    ip cef

    Use these commands on the incomming interface to change CEF load sharing algorythm:

    ip load-sharing per-packet
    ip load-sharing per-destination

    Use this command to check load sharing status for some particular prefix:

    sho ip cef <prefix> detail