etherchannel and trunking

[glen.grant]

Is there any real advantage to using PAGP or LACP for etherchannel over hardcoding the channel to on other than they make bringing up etherchannels a little easier , is there a diagnostic advantage ? Same question for trunking setting them up as desirable verus hardcoding them to on . I looked around on CCO and couldn't find a definitive answer .

[Prashanth Krishnappa]

Our best practice document should help

http://www.cisco.com/warp/public/473/103.html

"desirable" uses PaGP/LACP for etherchanneling and DTP for trunking rather than forcing the ports to be an etherchannel or a trunk.

[7rbowenii]

From experience I will say that 'best practices' don't always hold water. Cisco's implementation of PAGP best practices has changed time and time again. I currently hardcode my channels on to do away with the 'mystery' of how signalling is going to work each time a connection is made. I have also witnessed connections drop with no changes using auto-negotiating functions for etherchannel, trunking and 10/100. It's not worth the risk in a production environment as far as I'm concerned.