[c-nsp] VSS to vPC - vPC to Etherchannel

[Antonio Soares]

It's very easy to bring down a network when configuring "channel-mode on".
If we do it first on the root switch, the spanning-tree loop is already
there. Someone that wrote about this and explains some scenarios:

http://www.dasblinkenlichten.com/?p=684

"channel-mode on" is very bad and dangerous. I don't understand why some
design guides still have this...

Regards,

Antonio Soares, CCIE #18473 (R&S/SP)
amsoares at netcabo.pt
http://www.ccie18473.net


-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Gert Doering
Sent: sábado, 16 de Março de 2013 18:37
To: Joseph Hardeman
Cc: cisco-nsp
Subject: Re: [c-nsp] VSS to vPC - vPC to Etherchannel

Hi,

On Sat, Mar 16, 2013 at 11:28:42AM -0400, Joseph Hardeman wrote:
> No actually they are configured as "mode on" no LACP.  I spoke with a 
> CCIE a couple of years ago and he told me that use mode on from switch 
> to switch and lacp from switch to server so thats what I am putting in.

That was years ago, and is not good advice today.  Propably wasn't good
advice then, but that depends on "how many years ago"...

With LACP you'll *know* that both ports belong to the same channel on the
other side, and both are ready to be used, not "uh, link up, but line card
crashed" or "this is a multichannel LAG, and one of the chassis' is just
booting and not really participating yet", or such.

gert
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