Bundle-Ether over Multiple Line Cards

[Lyphiard]

The Cisco documentation for Link Bundling on the ASR9K routers says:

Multiple links can span several line cards to form a single interface. Thus, the failure of a single link
does not cause a loss of connectivity.

Since each line card has its own forwarding table, what kind of performance hits are expected when interfaces in a bundle-ether group are spread across multiple line cards as opposed to having everything on a single line card?

[balaji.bandi]

If you configure bundle with single line card the failure rate is high if the line cards malfunction or hardware failure- your service will be down connected to that bundle interface.

Cisco best practice if you have multiple line cards, spread the load in to  different line cards, even though one line card failure, service update is 100%, there may be small performance in terms of link utilization. example below case :

you have x 1GB spread in to 2 cards - you have 2GB Traffic - if one go offline, you see performance issue because only 1GB available bandwidth.

you can plan in better way depends on your requirement by adding more ports in to bundle you do not like to have performance effects.

make sense ?

[Aleksandar Vidakovic · Accepted solution]

There is no performance impact. Forwarding information is fully distributed. 

/Aleksandar