there is a strange issue we are facing since long time where few 6921 phones are not picking up valid ip.
They are taking ip as 0.0.0.0.
This is happening with only 6921(irrespective of their firmware version).
Few phones get registered when we change admin vlan to voice VLAN id .
Attached are the snapshots of the packet captures of one affected phone and one working phone
working phone f029295b68ef
Affected phone 0c2724ba188b
We can see affected phone is taking ip as 0.0.0.0. it taking it for a while and then phone displays IP address realeased.
When we assign IP manually the phone registers immediately.
