10-06-2016 01:45 PM
We have multiple hosts as of late that sucessfully pull a DHCP address and are domain machines that there is no A record being created for the host. I can do a reverse lookup on the IP and that works but not name to IP.
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10-06-2016 01:53 PM
10-06-2016 01:56 PM
Option 81 is NOT enabled on the scope. It looks like historically, we haven't turned that on. It seems odd that we've been OK up to this point but now we have some hosts that we are missing info on.
10-06-2016 02:06 PM
10-06-2016 02:24 PM
If DDNS updates are enabled in the DHCP properties, the DHCP server will attempt to add the A and PTR records along with a TXT record by default. This is controlled based on the TXT record handling configuration which is set to "ISC" mode by default.
The TXT record includes a hash value generated based on the clients MAC address. In ISC mode, if an A record exists, the TXT record must also exist and match the expected value. If an A record exists but there is no TXT record or the value does not match, then the DHCP server will not update the A record.
The system logs would help explain why any updates may be failing and assuming that your logs have not rolled, you can filter by the clients hostname (NOT FQDN). The other thing to check for is that the Updates ACL's on the zones only allow the DHCP server (which is done by default for Infoblox DHCP servers in the Grid) and special/statically configured clients to do updates. If this is open to DHCP clients, they can step on the DHCP servers toes.