MAC Learning behavior on cisco 7600 series

[Tim.Yu]

Can anyone tell me the MAC learning process is implemented on the ingress or egress board on Cisco 7600 series?

[Jon Marshall]

What exactly do you mean by board ?

Jon

[Richard Burts]

I agree with Jon that the question is not clear. But if it is asking about mac learning behavior then it should be pretty clear that mac learning is done on ingress and not on egress.

HTH

Rick

[Tim.Yu]

i am asking mac cpu processing is done one the linecard of traffic comming in or the one leaving. this behavior differs between vendors and has impact on some network design.

[Jon Marshall]

As far as I know, it is as Rick says, on inbound.

But I don't really follow the question. Because a switch can only learn a mac address when it receives traffic on an ingress port. Whether this be in response to an arp request or just data doesn't really matter.

How exactly could a switch learn a mac address any other way ? 

Jon

[Tim.Yu]

it is possible as if there are interfaces on different linecards belong to same broadcast domain, mac is need to be sync among linecards. in this case since mac need to be sync, then learn in incomming or outgoing is both reasonable.

[Jon Marshall]

I will take your word for it because to me I cannot see how a switch learns a mac address other than from ingress traffic.

Jon