--- In [email protected], "sameer2803" <sameer2...@...> wrote: > > Hi all, > Please help me out > > i have hosted a site www.example.com so the DNS config in zone file will be > as: > ; zone file for example.com > $TTL 2d ; 172800 secs default TTL for zone > @ IN SOA ns1.example.com. hostmaster.example.com. ( > 2003080800 ; se = serial number > 12h ; ref = refresh > 15m ; ret = update retry > 3w ; ex = expiry > 3h ; min = minimum > ) > IN NS ns1.example.com. > joe IN A 192.168.254.3 > www IN CNAME joe > Ignore if any mistake in the file. according to above file if we request for > www.example.com it will get the CNAME as joe and will follow the CNAME chain > unless it gets the A record for the site i.e 192.168.254.3. > > > If am not wrong,We can write the above file as > > joe IN A 192.168.254.3 > www IN A 192.168.254.3 > So what is the actual reason for using CNAME.just saying its used for alias > wont do.when we can write as ablove why to use canonical name,we can straight > away give the IP with A record. >
First of all, the following second entry is a host of example.com joe IN A 192.168.254.3 (joe.example.com. www IN A 192.168.254.3 (www.example.com.) u can write the following www.joe IN A 192.168.254.3 (that means www.joe.example.com.) FQDN . is your root server com is first level domain example is second level domain joe is third level domain www is a hostname For Cname joe IN A 192.168.254.3 www.joe IN CNAME joe IN Future IF u change ur Address record, then no need of changing for www host. So if you have mutiple hosts pointing to the same A record then using cname is understandable. Regards. B.Sadhiq
