09-13-2010 03:29 AM - edited 03-06-2019 12:56 PM
By default, PAgP operates in silent submode with the desirable and auto modes, and allows ports to be added to an EtherChannel even if the other end of the link is silent and never transmits PAgP packets. This allows a switch to form an EtherChannel with a device such as a file server or a network analyzer that doesn’t participate in PAgP |
■ EtherChannel on mode does not send or receive PAgP or LACP packets. Therefore, both ends should be set to on mode before the channel can form except.... ■ EtherChannel desirable (PAgP) or active (LACP) mode attempts to ask the far end to bring up a channel. Therefore, the other end must be set to either desirable or auto mode except.... ■ EtherChannel auto (PAgP) or passive (LACP) mode participates in the channel protocol, but only if the far end asks for participation. Therefore, two switches in the auto or passive mode will not form an EtherChannel except.... |
09-13-2010 06:10 AM
Hello,
You are correct in that the PAgP etherchannel will come up in certain cases
when you use the silent keyword along with "auto" or "desirable" keywords.
However, when you set the channel mode to "ON", you are configuring a layer
2 only etherchannel without any protocols managing the etherchannel. Hence
the PAgP does not apply here. When you are setting the LACP features, again,
since PAgP has no significance here, the "silent" feature is not required
here as well. In both "ON" mode and "desirable/active (LACP)" mode, we do
not need to talk about the silent feature. Only in the PAgP specific line,
you can mention "the except" clause.
Regards,
NT
09-14-2010 02:39 AM
Thanks for you answer.
So by default and according to the "defaut/silent mode", this combination could works?
PAgP/ON <==> PAgP/desirable: OK (it work because "desirable" or "auto" mode don't expect PAgP negociation packet in silent mode)
PAgP/ON <==> PAgP/auto: OK (same..)
PAgP/desirable <==> PAgP/auto: OK
PAgP/auto <==> PAgP/auto: OK
If it's true, this is in conflict with the Cisco rule wich saying:
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