Re: Web Server and DNS Behind C2621

anthony.barron · ‎11-08-2010

Hey guys,

I am trying to setup a web server and a DNS server but having some issues, was wondering if anyone here could shead some light on it for me.

My current setup is

WWW

|

modem (bridged)

|

C2621

|

LAN

I am having issues accessing a website on my web server from the internet. I have setup NAT properly and this works because i can access my FTP from the internet, just not my Website.I have a feeling it might be a DNS issue? I have a record for www to the public IP address of the web server but i am getting a DNS Lookup error when i try to browse to it... Yet Browsing to ftp://mydomain.biz works without issue.

Any help on the issue would be awesome

Cheers

jonathanaxford · ‎11-08-2010

Hi there,

If browsing to the FTP server by name works ok and the website (HTTP) has the same name, it is unlikely to be a DNS issue as that part of the connection should be identical at that level.

Is the DNS server hosted by an ISP/external company? What happens if you use the NSLOOKUP tool in windows to lookup www.mydomain.biz?

(Assuming you are using Windows...if not, some other name resolution tool!)

Many thanks

Jonathan

fingerlicked · ‎11-08-2010

Don't forget that there is a difference between "www.mydomain.biz" and "mydomain.biz" make sure you have an A record in your name server for @ and for www as the hosts.

anthony.barron · ‎11-08-2010

Thanks for the replys guys,

The DNS is hosted by me at my location on a Windows Server 2003 box. When the FTP site was working, my current DNS Setup was as follows

My domain register had its name servers for mydomain.biz pointed to zoneedit name servers and using zoneedit, it pointed everything to my public IP address and the NAT for port 21 was seding FTP requests through to the Web Server. There was an A Record for WWW to 203.217.XXX.XXX (My public IP) but whenever i browsed to the site www.mydomain.biz it would return with a DNS Resoloution failure.

I have since moved to the DNS Server 03 box as stated above and there are records that were pre entered when the server was promoted to a DC and the only other Records i have entered were a CNAME record for ns1 pointing to the FQDN of my DNS server and an A Record for WWW to the Public IP of my server (Which is behind the Cisco 2621 router) Since it takes a while for the name servers to update on my domain registers side, i will wait another day as it has only been around 20 hours since i pointed the name servers on my domain to the public IP of my DNS Server.

What i am sightly confused on is,

Is the NAT statments in my router config correct for what i am trying to do with the FTP, Web and DNS server? Any A Records in the DNS if they need to point to my internal IP of the servers or the Public IP's?

p.s when i was using zoneedit and the FTP site was working, an nslookup to mydomain.biz returned the correct information. But now it just doesnt reslove, most likely because the NS updates have not had enough time to replicate? And browsing straight to my public IP in a web Brower should return my website but it doesnt...

Im stating to go grey and thinking about getting proper DNS training. I once knew this stuff but data dumped it since i havnt used it in a while...

Cheers

margalla · ‎11-10-2010

Is the NAT statments in my router config correct for what i am trying to do with the FTP, Web and DNS server? Any A Records in the DNS if they need to point to my internal IP of the servers or the Public IP's?

I'd remove the redundant line referencing the non-existent ACL 101 and add a UDP translation for DNS.

!
no ip nat inside source list 101 interface Dialer1 overload
ip nat inside source static udp 10.0.0.2 53 interface Dialer1 53

!

Your DNS server should return the internal address for requests from internal hosts and the public address for requests from hosts outside your network.


And browsing straight to my public IP in a web Brower should return my website but it doesnt...

When you do this, do you see the expected NAT translations, "show ip nat translations"?

If you telnet to 80, does it open a connection?

If it does, and you then type GET /, do you get some sort of HTMLish response from your server?

anthony.barron · ‎11-11-2010

Thank you for your reply. I will try this after work tonight and ill let you know