Etherchannel on Cisco IOS Catalyst Switch

Hello Hisham

Yes, you are correct, the command no switchport is not used in this configuration. This means that this EtherChannel setup is a Layer 2 Etherchannel connection. That is why DTP is running, and that is why you are able to configure the link as a trunk just by configuring a trunk port on only one end of the EtherChannel as stated in the previous post. All of these features are Layer 2 features.

If you were to use the no switchport command, you would be configuring a Layer 3 EtherChannel link. For more information about that, take a look at this lesson:

I hope this has been helpful!

Laz

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Laz,
I ran show etherchannel 1 detail command line on my switch as you can see below


It looks the load is zero for both ports. I want to know the amount of load so I can choose what’s best method of load balance to have (i.e. src-mac, dest-mac, …etc.). But as you can see the results came back zero. Do you know a better way to see how much traffic on this port?

Also, this switch has several hosts connected to it, and it’s connected to another switch via fiber etherchannel, it also the main source of internet.

Another question I have is confirm my understanding that it’s better to select a protocol such as LACP or PAgP if you want to perform etherchanel between a switch and server rather than On mode. And if weed to etherchannel two switches then no problem to choose the mode ON. Please confirm my understanding. Thanks for your help!

Hello Eyad

Hmm, that’s strange. I labbed this up to see what kind of traffic I could see on my switches, but I too see that both the load and the number of bits remains zero. I’m not sure why. I’ll continue to look into it however…

To answer your question, the load balancing method you should use depends upon your topology and your expected traffic coming in on each end of the portchannel. Take a look at this post to see how you should approach this issue:

Now once you implement your load balancing algorithm, how do you check to see if traffic is sufficiently balanced? On older platforms, you could use the test etherchannel load-balance interface port-channel command with appropriate IP and MAC address parameters, and this would tell you out of which port such a packet/frame would be forwarded. But on newer devices this is unavailable. The best way to determine this, and to gain full visibility is to use a network management system with SNMP such as Observium, that will show you over time the actual traffic on each individual physical link. No CLI command comes close to such clarity. However, for a quick and dirty method, take a look at the interface statistics of each physical interface. There you can determine if the traffic on each interface is comparable, or if one link is being favored over another.

I hope this has been helpful!

Laz

Hey all,

I am looking for some help regarding the LACP bundling time, and how I can speed that up.

This question has cropped up a few times for me, but I can find little help online regarding tweaking LACP bundle times.

I have seen that some devices support LACP Fast Rate - however this seems to be more of a keep alive once the bundle has been established.

Some people are suggesting actve/active is fast than active/standby - but I cannot find any support for this.

In my own research I can only find the LACP-Max-Bundle combined with the LACP fast-switchover command to be the only effective way of speeding this up .

Does anyone know of anything specific I am missing that can speed up the link-budling process?

Thanks,

Sebastian.