ethernet loopback internal ASR9K

[Peter L]

Hi

Been testing the Ethernet loopback internal function in the asr9k. Wasn't that much information about it in the normal documentation but got it up and running quite easy.

Just wondering exactly where on the line card the loop is applied?  Seems to be after the output policy, but it would be good to know where this is happening so you know how the traffic will behave. Is there any difference on behavior when running eth loopback internal  on a port/vlan?

Regards Peter

[xthuijs]

hi peter,

the loop is applied after the hw forwarding completes in the outbound direction, and is done before any inbound hw processing on the ingress direction.

Although there is a slight difference in the way non 40G goes as opposed to 40G (that is the different asic where the loop is happening) the concept is pretty much the same that the ingress loopback internal is done after all egress processing but before the optical piece.

I think this visualizes it nicely too (or hopefully :) :

https://supportforums.cisco.com/document/145166/asr9000-11040100g-lanwanotn-white-paper#loopback

xander

[Peter L]

Hi Xander

Thanks for the update. Exactly what i was looking for.

/Peter