Similar to my post on DTP negotiation, this is just my way of remembering the nuances of EtherChannel negotiation…
Mode On = No negotiation takes place
PAgP (Cisco proprietary)
Desirable: send PAgP packets
Auto: listen for PAgP packets
D+D = EtherChannel
D+A = EtherChannel
A+A = No EtherChannel
LACP (Industry standard)
Active: send LACP packets
Passive: listen for LACP packets
A+A = EtherChannel
A+P = EtherChannel
P+P = No EtherChannel
Carry on…nothing else much to see here.
http://ciscocertifiedhell.com/2009/07/31/dtp-negotiation-for-dummies/
