[AusNOG] The occurrence of duplicate MAC addresses

[Scott Weeks]

From: Lincoln Dale <ltd at aristanetworks.com>
On Fri, Feb 8, 2013 at 6:07 PM, Gavin Tweedie <gav at narx.net> wrote:

> Bad luck for guy #2 who rocks up to the peering point with the same MAC as
> an existing member eh? Or potentially bad luck for both if nobody notices
> before they connect.

best practice in any peering point is to disallow mac-moves like that - so

  switch#conf t
  switch(config)#int et17
  switch(config-if-Et17)#mac-address ?
    H.H.H  MAC address
---------------------------------------------



Easier scaled in cisco-ese:

switch#conf t
  switch(config)#int ran f1/0/1-48
  switch(config-if-range)# switchport port-security violation restrict
  switch(config-if-range)# switchport port-security mac-address sticky

The first guy that plugs into the port wins, though.  That may not
be the one you want in less physically secured data centers.


scott