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In article <Pine.GSO.4.58.0505122131110.1403@xxxxxxxxxxxxxxxxxxxxxxxx>,
James Muir wrote:
>When I put
>
>http://www.nserc.ca
>
>in my browser I get a "host not found" error. Very occassionally (maybe 1
>in 15 times) the web page will come up. When I put
>
> 198.96.3.190">http://198.96.3.190
>
>in my browser everything works fine.
That's certainly a DNS issue, but remember that your browser is merely an
application that is using the resolver code in the kernel.
>(I should add that a month ago I wasn't experiencing any of these
>difficulties).
Well, the question all admins hate to ask is "What did you change?"
>So it seems like there is some DNS issue. I have repeatedly queried my
>DNS server using "dig www.nserc.ca +short".
The only thing that 'dig' (and other DNS query tools) do differently from
what the normal name resolution process does is that these tools ignore
/etc/host.conf and /etc/nsswitch.conf.
>;; connection timed out; no servers could be reached
That's pretty explicit.
>When I query a different DNS server, there's no problem:
which should be a clue.
Possibility 1. The addresses you have in /etc/resolv.conf for nameservers
are no longer correct. Is this router running a DHCP server that is telling
your system to use some stupid nameserver address (like it's own)?
Possibility 2. You've got a firewall rule problem. This can happen when
you have some 'automatically block anyone who attacks you' helper, and
one of your "friends' hit you with a tool like nmap using the -D option.
Wouldn't be the first time some one shot their own foot.
>Now, the weird part is that this problem seems to magically go away when I
>remove the router. That is, when I'm plugged in directly to my modem the
>DNS queries come back undamaged and entering www.nserc.ca">http://www.nserc.ca into my
>browser works fine.
So look at /etc/resolv.conf now. Different? If not, it's likely a firewall
fiasco on your router.
>I am having a hard time accepting the fact that the router is at fault.
because?
>My ISP claims that the DNS server is fine.
Probably so - and when you bypass the router, things are OK.
Old guy
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