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I am an user of Ubuntu 10.04 (x64) on a laptop computer.

Everything are usually fine and there is no problem including network. However, when I connected a network at a hotel, DNS resolution from network programs, such as firefox, ssh and ping, did not work properly. All these programs could not resolve the IP address of the target (timeout).

Interestingly, dig and nslookup worked fine and correctly get answer from the DNS server in the hotel network. Further, if I switched to Windows 2000 on vmplayer on the same Ubuntu 10.04, the firefox on Windows could correctly resolve DNS.

When I checked resolv.conf, dhcpclient program did put the correct DNS server IP address into resolv.conf. Using dig and nslookup without specifying DNS server IP, like dig, it could get proper information of DNS of the site. In addition, I captured the packets using tcpdump. The packets from my computer emitted to the DNS server in all cases, but DNS server only replied to dig, nslookup and Windows OS on vmplayer.

I could not find any pointer to solve my strange problem. If somebody could give some suggestion, I would highly appreciate.


share|improve this question
Compare carefully the packets that worked with the packets that didn't. – David Schwartz Feb 17 '12 at 2:50
Do you have "auto detect proxy server" set up in Ubuntu global proxy settings? – Paul Feb 17 '12 at 4:17
Thank you, David and Paul, the connection is direct and not use proxy or not set auto detect proxy. The problem was not only firefox but also ssh and ping etc. Therefore the reason is more general of DNS query. Currently, I can not check details of the packet because I left from the hotel:) Does someone have similar experience? – goro Feb 17 '12 at 7:53

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