On a production Nexus 5K, I noticed the following piece of config:

interface Vlan1
  mac-address 0000.0000.0000 

This is the entire Vlan1 stanza. What does this accomplish?

  • 2
    Are you the only technician that has access to this switch? I'm wondering if someone manually put this in there. If that is a possibility, I may be able to give you additional insight.
    – Ryan Foley
    Mar 7 '14 at 8:09
  • @Fizzle That is the case -- there are other people with access, and I suspect this was manually put in to address ... something. Initially I discovered this as I was auditing configs and sync between 5Ks.
    – belacqua
    Mar 7 '14 at 22:25
  • Is there a Cisco ACE on the subnet? How about a Layer 3 card? We ran into an issue on a Nexus 7k where there was strange interaction between vPC, ACE and pinging SVIs that required statically setting the SVI MAC Address
    – Ben Mason
    Mar 31 '14 at 12:58
  • No ACE on the subnet, so unfortunately can't be that bug. Thanks.
    – belacqua
    Mar 31 '14 at 23:12
  • 1
    It could be an attempt to disable vlan 1 by someone who mistakenly thought that was a good thing to do on a cisco switch. Mar 19 '15 at 2:21

Might be related to this known bug?


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