I have a mixed network of Windows and Linux clients and we are using Windows 2008 R2 server for both DHCP and DNS service on the network. The DNS servers are on DCs and the DHCP server is operating on a different server (a cluster actually.) On the DHCP server I've set the DNS tab to Always dynamically update DNS A and PTR records (DNS dynamic updates are enabled,) Discard A and PTR records when lease is deleted, and Dynamically update DNS A and PTR records for DHCP clients that do not request updates (just turned the latter option on today.) I am not using Name Protection.
The problem is that Linux clients are not getting their hostnames registered. Mac's are working fine as are the Windows clients, but no dynamic Linux clients are in DNS. I've tried setting DNS to accept both Secure and Insecure Updates, but really, that shouldn't matter here since the updater is the MS DHCP server, a trusted source, correct?
I've tried various things on the Linux clients (all RHEL variants,) like ensuring DHCP_HOSTNAME is set in the ifcfg file, making sure their hostname is set properly, etc., but none have solved the problem.
Aside from an actual solution, can anyone suggest a way to debug this, like monitoring the DHCP dialog between client and MS DHCP server or the DHCP to DNS server requests?