Etherchannel silent/non-silent

c.lemaire · ‎03-08-2006

Hello,

Does anyone know what are the etherchannel parameters silent/non-silent used for?

I've read the following info from CCO but I don't understand

silent : Keyword that is used with the auto or desirable mode when no traffic is expected from the other device to prevent the link from being reported to the Spanning Tree Protocol as down. (Default)

non-silent : Keyword that is used with the auto or desirable mode when traffic is expected from the other device.

How can you expect not to receive traffic from a port? What has the spanning-tree to do with this?

Thanks in advance for your enlightment,

Christophe

ankurbhasin · ‎03-08-2006

Hi Christophe,

Certainly there are some instance when there is no traffic from the peer connected to the switch port and the traffic comes when you initiate the device as an example packet analyser.

Traffic will only come when you initiate the packet analyser to work.

The silent mode is used when the switch is connected to a device that is not PAgP-capable ) non cisco device ) and seldom, if ever, sends packets.

An example of a silent partner is a file server or a packet analyzer that is not generating traffic. In this case, running PAgP on a physical port connected to a silent partner prevents that switch port from ever becoming operational; however, the silent setting allows PAgP to operate, to attach the interface to a channel group, and to use the interface for transmission

If your switch is connected to a partner that is PAgP-capable, you can configure the switch interface for nonsilent operation by using the non-silent keyword. If you do not specify non-silent with the auto or desirable mode, silent mode is assumed

HTH, if yes please rate the post.

Ankur

c.lemaire · ‎03-09-2006

Hi Ankur,

Thank you for your answer. But I still have some questions...

1) Why would I want to configure a PAgP channel on ports connected to a not PAgP-capable device? I think I would go for a channel in 'on' mode (not auto or desirable).

2) If a device is PAgP capable, it will always answer to PAgP packets sent by the switch, won't it?

3) When I configure a channel between two Cisco switches, silent AND non-silent mode work perfectly... Why should I bother about it as silent works for every cases?

My questions may seem silly, but I love to understand what I'm doing.

Regards,

Christophe