Subdomains for DHCP-enabled clients

[Kevin Darcy]

Phusion wrote:
> I have been working on setting up DHCP and DNS and have been having
> problems with dynamic DNS for the DHCP enabled clients. I have a zone
> file for test.com for servers, etc, and another zone for DHCP-enabled
> clients named mdnlan.test.com. Currently, the DHCP-enabled clients get
> an IP address and have a computer name of hostname.mdnlan.test.com.
> These clients use dynamic DNS and update the mdnlan.test.com zone
> file. Servers have DNS names of hostname.test.com and accordingly are
> in the test.com zone file. Here is an example of what I can't get
> working. Here are the computer names.
>
> DNS server = smdndns.test.com
> Test PC (DHCP client) = testpc.mdnlan.test.com
>
> Ping from testpc.mdnlan.test.com to smdndns = fails
> Ping from testpc.mdnlan.test.com to smdndns.test.com = works
>
> Ping from smdndns.test.com to testpc = fails
> Ping from smdndns.test.com to testpc.mdnlan.test.com = works
>
> I assume the problem has to do with the domain suffix or domain search
> list. How can I go about changing this on the server so computers on
> both domains can talk to each other. Also, I would prefer not to have
> to manually add the server entries to both the test.com zone and the
> mdnlan.test.com zone file.
>
>   
You don't change this on the server, you change this on the client. For 
a DHCP-enabled client, you can supply a "domain name" option (Option 
#15) from the DHCP server, which should be honored by the client. 
Otherwise, you'll need to statically configure the client with this.

Generally speaking, though, from a DNS infrastructure perspective, it's 
better to get into the habit of using FQDNs (fully-qualified domain 
names) for everything. That gives you the most efficient DNS resolution, 
with no ambiguity.

                                                                         
                                    - Kevin