enter image description here

Questions: How does etherchannel will loadbalance traffic here when traffic coming from internet, L3 will hash IP src-dst but one that traffic pass to first L2 switch (distributed) how does that traffic will loadbalance on 2G link using src-mac? what src mac address it would use and shared traffic?

1 Answer 1


If the channel balancing on a switch is based on the source MAC address, and you have a single MAC address sending the traffic, then the traffic will always use the same channel member link.

Remember that a MAC address will not cross a layer-3 device. The layer-3 switch will create new frames for traffic coming from the ISP, and the source MAC address will be its own MAC address.

If you have multiple VLANs, the layer-3 switch may have a MAC address for each, or it may have the same MAC address for all your VLANs. You can use the show interfaces command to see how your Cisco layer-3 switch does it; just look at the SVIs' MAC addresses to see if they are the same.

Once the traffic gets to the first layer-2 switch, the traffic will be biased toward a single link on the channels to the other layer-2 switches, at least per VLAN, and possibly for all the traffic.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.