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Old 12-12-2007, 10:15 PM   #1
jroyce
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DNSMasq not serving requests from external PCs


I recently installed dnsmasq on my linux box. Everything seems to be working ok locally--I changed the resolv.conf to show that the loopback address is the nameserver and when I do an nslookup (locally) I get a very quick reply:
Quote:
Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
Name: www.linuxquestions.org
Address: 64.179.4.46
The problem I have is when I set a Windows box on the same LAN to use the Linux box as the DNS server. NSLookup on my Windows box results in timeout errors and the address never resolves.

I have set up Shorewall to open requests to port 53 and I can successfully telnet into port 53, so I don't think it is a firewall issue.
 
Old 12-13-2007, 06:43 AM   #2
jroyce
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BIND is the same

UPDATE: I removed dnsmasq and installed BIND instead, just to see if it is an issue with DNSMasq. BIND has the same issue. Local requests (via my terminal window) work fine. Requests from other PCs do not.

So now I am figuring that it is a firewall issue. I've opened port 53 in both directions (from fw to net and from net to fw). Are there other ports which need to be opened?
 
Old 12-13-2007, 09:57 AM   #3
jroyce
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Question Does port 53 need to be open to both UDP and TCP requests?

I have been reading a bit more about how DNS works and one site mentioned that the initial request comes in via UDP on port 53 (and then reverts to TCP if the reply is too large for a UDP packet). Is this the case and if so do I need to open port 53 for UDP requests in Shorewall? (Right now it is only configured to allow TCP requests.)

Thanks for any help you can provide!
 
Old 12-16-2007, 11:38 AM   #4
archtoad6
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Why did you install dnsmasq on what sounds like a desktop box? -- I have only encountered it in firewall distros like SmoothWall & IPCop.
 
Old 01-11-2008, 05:43 PM   #5
archtoad6
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Well . . .
 
Old 01-11-2008, 08:54 PM   #6
KnightHawk
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I'd recommend testing not using the localhost IP, but the real IP. I assume you gave the windows clients the real IP, and not 127.0.0.1
 
Old 01-12-2008, 09:18 AM   #7
archtoad6
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jroyce,
Please answer post #4.
 
  


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