DNS /var/named/named.hosts

Richtown · 04-23-2007, 10:22 AM

Hi,

I am wrtting the following file "/var/named/blast.hosts" and was wondering about the line highlighted in bold. Will DNS run without this line? I understand that it's a alias for the hostname but when would you use it?

@ IN SOA darkice.blast. root.darkice.blast. (
2006112100; Serial Number Year Month Day Serial Number
28800; Refresh
14400; Retry
3600000; Expire
86400); Minimum
IN NS darkice.blast.

localhost IN A 127.0.0.1
darkice IN A 192.168.1.124
darkice IN A 172.16.87.1
client IN A 172.16.87.129

cl IN CNAME client

Kind Regards
Rich.

MensaWater · 04-23-2007, 12:06 PM

Yes it will run without it.

CNAME records are pointers (think of them as aliases). You can set them up so your system can be accessed by these aliases.

Say you wanted to have people think of your "darkice" like a black gem such as "onyx". You already have the address record equating darkice to the IP so you just create the CNAME:

onyx IN CNAME darkice.darkice.blast.

Anyone looking for onyx in that zone will find it and immediately go to the IP you assigned to darkice in the earlier A record.

ramram29 · 04-23-2007, 12:09 PM

Yes, you can run it without your cl cname. a CNAME is a canonical name or an alias or a nickname. Hence, connecting to cl.darkice.blast is the exact same thing as connecting to client.darkice.blast. People mostly use it for virtual hosts. For example, if you have www.example.com, ftp.example.com and webmail.example.com, all being hosted on the same IP address then you can create CNAME's for all of them but one.

Richtown · 04-23-2007, 02:04 PM

Thanks guys, that makes it easier for me to code my php interface for dns.

:-)