Wireshark · Wireshark-users: Re: [Wireshark-users] Can ethernet PC-Switch speed negotiation be captured by Wireshark?

[Stephen Fisher <steve@xxxxxxxxxxxxxxxxxx>]

On Fri, Jun 19, 2009 at 03:38:27PM -0700, Janis.M.Bishop@xxxxxx wrote:

> Can ethernet PC-Switch speed negotiation be captured by Wireshark? If 
> the answer is yes, how does one filter on it?

No.  The auto negotiation takes place with electrical signals before the 
interfaces come up to the operating system and Wireshark.  However, the 
Cisco Discovery Protocol will report the duplex the port you're 
receiving packets from is set to.  LLDP may have that as well.


Steve