Which router supports 802.3ad ?

Unanswered Question
May 12th, 2008

I have a 3845 router and IOS c3845-advsecurityk9-mz.124-13 and I didn't find any command to set LACP (Link Access Control Protocol).

I tried as well on 7200 and as well no command to set LACP was present.

So I'm really surprised, is really Cisco supporting only its proprietary Etherchannel with Port Aggregation Protocol and not as well the 802.3ad ?

I have this problem too.
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Overall Rating: 4 (1 ratings)
cisco_lad2004 Mon, 05/12/2008 - 08:04

below you can see the options to set etherchannel as either Pagp or LACP ( I used 7609).

In short:Active and passive are for LACP. desirable and auto are for Pagp.Cisco recommendation is desirable both ends, I prefer ON.

Pls rate all helpful posts


TST-POP1-NPE01(config-if)#channel-group 1 mode ?

active Enable LACP unconditionally

auto Enable PAgP only if a PAgP device is detected

desirable Enable PAgP unconditionally

on Enable Etherchannel only

passive Enable LACP only if a LACP device is detected

badalam_nt Mon, 05/12/2008 - 23:28

Thanks Sam.

I will rate your post, it could helpful for people needing 802.3ad settings.

After searching for a while on Cisco website, my understanding is that 802.3ad is supported only on some combinations of platform & IOS.

For Cisco 3845 router, no matter what IOS is used, it seems 802.3ad is NOT supported at all. So this explains why I had no command available to set LACP. Bad luck, as I tried to use it in a multi-vendor environment connecting it some other equipments, which support 802.3ad in addition their own proprietary link aggregation protocol (different from Cisco's EtherChannel of course).

For Cisco 7200, apparently for some IOS this LACP 802.3ad is available.

I'm on the process to receive one of those IOS supporting 802.3ad, then I will load it on my 7200 and try to see if these commands are available.

cisco_lad2004 Tue, 05/13/2008 - 00:22


Thanks for the rating and for sharing ur findings with us!



Joseph W. Doherty Tue, 05/13/2008 - 04:00

Just a guess, but what I suspect sometimes happens is Cisco is sometimes a bit late to the party when a standard method provides a solution that they already solved with a proprietary solution; another example has been VRRP.

badalam_nt Tue, 05/13/2008 - 08:53

Some updates:

Still pending the conclusion about 7200, we're going to ask Ask Cisco if the 7200 or the 7206 is really supporting LACP (802.3ad).

In the meantime one more "surprise": 802.3ad is not supported by Cisco 7201!

We tried to configure LACP on 7201 but again the luck was not on our side.

“Cisco is indicating that LACP is supported on Cisco-7201 according to the CCO documentation, but internally a “TME” indicates that this is not supported on the Cisco-7201. It is also not possible to configure this on the current Cisco-7201 routers."

badalam_nt Tue, 05/13/2008 - 09:50

And to add that configuration with LACP 802.3ad on other vendor equipment's side + EtherChannel on Cisco 3845 side didn't work, no traffic was possible.


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