It appears that you have gotten quite far in setting up DNS. If I
right, you have two copies of named running on your boundary machine, one
to field DNS requests from outside your private network, and one to handle
internal requests. So far, so good.
Most ISPs will not give you the rights to supply the reverse-lookup
for your system, even if you are supplying the forward translation. The
that the reverse lookup data spans a large number of customers, of which you
To check on how you are perceived by the outside world for either forward
reverse lookups, you can use nslookup (at least in current leases of Linux).
recommendation is to simulate what a "random" user would do if it wanted to
up your domain.
1. Contact a root server [you can find their addresses in named.ca] and
to resolve the name. It probably will not do this directly, but will
redirect you to
the "primary" authoritative source. nslookup has a server command that
to specify which server you want to talk to.
2. Contact that server, and repeat the request. The reply will be the
information on your domain.
3. If you want to find out which *other* servers might leap into the gap
primary server is down, try whois. It will return to you the definitive
about which name-servers are acting for your domain.
> I need some help in figuring out if what I have is correct. I am on
> a cable modem at home. My ISP has a host record for my ip address
> let’s say 1-2-3-4.client.ispname.com (for ip 126.96.36.199). I bought
> a domain name (let’s say example.com) and pointed my nameserver
> name to my ip address (188.8.131.52). So ns.example.com is pointing to
> I have dnscache accepting on an internal ip (192.168.1.1) and tinydns
> on my external interface (184.108.40.206). I am able to reach the internet
> just fine from my network at home. When I do a nslookup or ping
> –a on 220.127.116.11 (from a windows machine), my isp’s host name
> is resolved (outside my network). Is there a way so that when I do a
> reverse lookup on my ip address, my dns server name is resolved (from
> outside my network). Also, If I have an alias let’s say
> ftp.example.com, mail.example.com, should I be able to reach it by
> pinging it, or doing nslookup from outside the network? Inside my
> network, all of these things that I mention work just fine (reverse
> lookup will yield the correct name, aliases return response, etc).
> What ways can I verify that my dns is actually working from the
> outside. My ultimate goal to have my own mailserver for example.com.
> I also added an mx to the “data” file for the mail
> server. Any help would be greatly appreciated.
> Sanjiv Patel