MAC Address Changing

[clark white]

Hello

I have 3905,6921 phones who's MAC is changing automatically and then they are getting unregistered. I am using CUCM 9.1

Since 9.1 was working from last year without any issues but all of sudden strange issues have arised.

Thanks
 

[George Thomas]

Not sure what you mean by MAC is changing automatically. Not quite sure how thats possible unlike IP addresses.

[clark white]

Dear George,

Yes i was also wondering, when my colleague told me but when i saw it was very strange for me. with some phones when i add a 3905 phones with proper MAC for ex: (aaaa.bbbb.cd01) they get registered the next day the phone is unregistered when i see the phone in CUCM its mac changes to aaaa.bbbb,cd02

very strange i have never come across such situation and also not found anything on support community

[Aman Soi]

Hi Clark,

Not sure whether this bug is appropriate for your issue

Have a look :

6921 not sending immediate CDP upon PC disconnect

CSCtj92865

Description

Symptom:
6941 6921 6961 when plugging a different PC the switch port goes into err-disable state with the error "new MAC address is seen".

Conditions:
Using dot1x
plugging a different PC

Workaround:
wait for some time before plugging the new PC. The phone needs to send CDP to indicate that the pc port is disconnected so it can log off the session.

Known Affected Releases:

(1)

regds,

aman 

9.0(3)