96x1g DHCP ACK

[rickpeay]

Could not find a solution for this online anywhere... lots of guesses and work-arounds, but no solutions.

We have several 9611g sets deployed across several locations; along with several other H.323 set types. 9611g desk phones at one of our sites started freezing and displaying "DHCP ack error". We determined that when these phones reset, or tried to renew their IP leases, they would freeze and display this error.

After much searching, testing with a user on site (language barrier), and multiple changes by our network team, it was determined that there was a rouge DHCP server on the LAN; in addition to our planned DHCP server. When the phone would successfully try to re-boot and received a valid IP via DHCP and be set to the Voice VLAN (as configured in the 242 String), a second DHCP ACK would hit the phone (with a different IP address and lease). The phone (as designed) would reset the IP to 0.0.0.0 and freeze. We were also seeing several "ip-a" changes for the affected stations in list history.

The fix was to restrict DHCP assignments from only the port connected to our DHCP server. It was later determined that a device had been connected to the LAN that had DHCP turned on.

Hope this helps the next person that has this issue.

RP

[bucky101]

Is your DHCP server plugged into a non-trunk port. AKA an access port for the Voice VLAN only?
Try that