I've noticed something interesting while using Angry IP Scanner. Some hostnames are displayed with a domain suffix at the end, like 'examplepc001a.example.domain', while others only show the hostname, such as 'examplePC001a'. I also found out that this location is using Webmin for DHCP. It seems like some PCs are using DHCP to get IP addresses while others are older machines that show up instead of the newer ones. What's causing this difference in how the hostnames appear, and how can I fix the older machines showing up?
2 Answers
The reason you're seeing the domain suffix is due to the DNS suffix search order. Machines that have a domain suffix configured, either through DHCP option 15 or manually, return a Fully Qualified Domain Name (FQDN). Those without a domain suffix just return the hostname. Angry IP Scanner does a reverse DNS lookup, so if a PTR record exists with the domain, you'll see it. Make sure to check your DHCP scopes for proper settings.
Building on what TechieTim said, not all devices on your network may be using DHCP, so it's worth checking if they all have the right DNS entries. That might be why you see some older machines appearing without domain suffixes.
I noticed some PCs are using DHCP for their IPs. When you mention DNS entries, do you mean those settings on the individual PC or in Webmin?
Ahh, this makes sense now! I understand why it happens, and I’ll work on fixing it.