Eigrp load-balance traffic view

[feroz syed]

Hi,

currently router 3 has two successor path to reach Router 2  10.1.102.1/29 subnet, is there any way to view of how traffic is shared between the two links or how it switch between both link(s1/0, s1/1).

I try this one { access-list 100 permit icmp any any echo} with debug ip packet 100. but unfortunately all packets flow through se 1/1.

P 10.1.102.0/29, 2 successors, FD is 2681856

        via 10.1.103.1 (2681856/2169856), Serial1/1

        via 10.1.203.2 (2681856/2169856), Serial1/0

[cadet alain]

Hi,

sh ip eigrp topology 10.1.102.0 255.255.255.248  will show you the share ratios.

Don't forget that CEF load-shares per src-dst  IP pair and so for 1 src-dst pair trafic will always use the same path.

To see for a specific src-dst IP pair which path CEF chooses: sh ip cef exact-route x.x.x.x  y.y.y.y  where x.x.x.x is src IP and y.y.y.y is dst IP

Regards

Alain

Don't forget to rate helpful posts.

[feroz syed]

it can be done by disabling the CEF mode ?

[cadet alain]

Hi,

if you disable CEF then you either fallback to cache-switching or process-switching and in latter case you will be doing per-packet load-sharing but it is highly discouraged to do so in production networks.

Regards

Alain

Don't forget to rate helpful posts.

[Nagendra Kumar Nainar]

Hi Feroz,

When you have 2 paths in your table, CEF will take care of load balancing the traffic based on certain parameters. It normaly takes source and destination IP address as key input into a hashing algorithm to get the path.

You can use "show ip cef exact-route <> <>" to see whcih stream/flow is flowing over whcih interface. (Depending on the platform, you may need to use hardware commands as well).

-Nagendra