difference between L2 & L3 etherchannel

sayhi2shashi · ‎02-09-2007

hi

can any one tell me what is difference between Layer2 and Layer3 ether channel

regds

Shashi

spremkumar · ‎02-09-2007

Hi Sashi

AFAIK configuring L2 and L3 etherchannel depends on the end equipments which you using and the connectivity between them

If you are using simple Layer 2 switches (between which you have the port bundles) then you can go ahead and configure L2 Etherchannels but in case of your bundle getting terminated then the router will treat them as a L3 link and need an ip address assign to it.

regds

Jon Marshall · ‎02-09-2007

Hi

Etherchannel combines multiple physical interfaces into one logical interface.

A layer 2 etherchannel is used between two switches, often configured as a trunk (although it doesn't have to be) to pass layer 2 vlan traffic. Spanning-tree runs on the etherchannel with the advantage that the etherchannel is seen as one link to spanning-tree so none of the individual links within the etherchannel is blocked.

Layer 3 etherchannel is configuring etherchannel as a routed interface on the switch. Switching functions are disabled and the you would configure a single IP address for the etherchannel connection. Spanning-tree is not run on this link as it functions at layer 3.

HTH

Jon

sayhi2shashi · ‎02-09-2007

hi Jon,

does L2 ethernel will be created to extend the Vlan from one switch to another switch.

regards

Shashi

Jon Marshall · ‎02-09-2007

Hi Shashi

Yes it can be used for that. The primary reason to use Etherchannel is to get more bandwidth on your links between switches.

From a logical point of view it is just a single connection between your switches. You can either confgure the etherchannel to just carry one vlan traffic across the link, ie an access port. Or you can configure the etherchannel as a trunk which allows you to carry traffic for multiple vlans across it.

More often than not layer 2 etherchannels are configured as trunks also.

HTH

Jon