A Record Question

[Kevin Darcy]

There's nothing technically wrong with having multiple names resolve to
the same IP address. The only sticky thing about it is a reverse-mapping
ambiguity: should x.x.x.x resolve back to "ns0.toserveandcollect.com" or
"gateway.pawd.net"? Generally, this reverse-mapping ambiguity doesn't
cause any problems -- usually no-one cares much what a
*server's* address maps back to, and even if your server machine
sometimes acts as a client for some protocol and the server at the other
end performs "double lookup authentication", everything will work as
long as the reverse-mapped name resolves to the client's IP address,
i.e. the PTR record for x.x.x.x points back to either "gateway.pawd.net"
or "ns0.toserveandcollect.com", and both of those names point to
x.x.x.x.


- Kevin

tim at pawd.net wrote:

> Is it possible to have 2 A records for the same IP address (same
> machine)? e.g. I have a dns server at home which has an A record for
> gateway.pawd.net, which is at my work. gateway.pawd.net is a DNS
> server, runnung DNS for the domain "toserveandcollect.com". I also
> have an A record in that zone file for gateway.pawd.net called
> ns0.toserveandcollect.com. IS this right, or am I going to run into
> any errors?
>
> zone file for toserveandcollect.com (I have left out the actual IP
> numbers):
>
> toserveandcollect.com.    IN SOA gateway.pawd.net. tim.pawd.net. (
>                           199802151       ; serial
>                           8H              ; refresh, seconds
>                           2H              ; retry, seconds
>                           1W              ; expire, seconds
>                           1D )            ; minimum, seconds
>
> ;
> ;name servers
> ;
> toserveandcollect.com.    IN NS          gateway.pawd.net. ; Inet
> Address of name server
> toserveandcollect.com.    IN NS          trinity.pawd.net. ; Inet
> Address of name server
>
> ;
> ;addresses
> ;
> toserveandcollect.com.    IN A      x.x.x.x
> www                       IN A           x.x.x.x
> ns0                       IN A           x.x.x.x
> ns1                       IN A           x.x.x.x