We have few Cisco 6921 phones currently registered with our CUCUM BE3000.
We have migrated to a new AD DHCP server, but having problem with phones that are switched off and back on again. they don't simply register with the new DHCP server. CUCUM can ping and communicate to DHCP server, but phones that are restarted, have no luck. The phones there were left switched on, are working properly.
any idea what else needs to be changed/tested?
Solved! Go to Solution.
we migrated DHCP records like-for-like. so there wasn't any need to modify the server apart from unauthorizing the old one and authorizing the new one.
However, spent some time on our gateway switch and discovered that IP helper for the voice vlan was pointing to the old DHCP server, hence the failure of relaying requests to the new server.
changed the IP helper IP address and everything seems to be working as normal.