We have a single DHCP server providing DHCP services for round 23 sites.
Recently we migrated our DHCP services from a Windows Server 2003 server to Windows Server 2008R2. I’ve enabled, Routing and Remote Access Services (RRAS) - IP Routing - DHCP Relay Agent on the old 2003 server to relay DHCP requests on to the new 2008R2 server. I can see the on the old server DHCP Relay Agent Requests received increasing and the new DHCP server is responding by renewing DHCP leases. All good.
Our ISP has now updated all our company site routers IP Helper configuration to forward DHCP request directly to the new 2008R2 DHCP Server. Eventually the old sever will be decommissioned. I believe, I should now start to see less requests going to the old 2003 server, that has DHCP Relay agent enabled. I suspect we still have some remote sites with the routers IP Helper still pointing to the older DHCP server instead of the new.
(I know this is a backwards way around of migrating DHCP services. i.e. it may have been much easier to give the new server the same IP address as the old DHCP server after turning off the old server, instead of changing all the sites routers IP configurations.)
What I need help with now is, how can I determine what computers are still requesting DHCP renewals form the old server? Is there a log file for the DHCP Relay Agent, I can inspect?
Thanks, Andrew
