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My Ubuntu 20.04 computer cannot browse any website. This only happens when connected to eduroam WIFI.

ping 8.8.8.8 works, but host google.com 8.8.8.8 says

Connection timed out; no servers could be reached.

I am not an expert on computer networks, could anyone tell me what is the next step in troubleshooting?

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    I'm not very familiar with eduroam, but I think it require you to use its DNS server (rather than a generic public server like 8.8.8.8).
    – Gordon Davisson
    Sep 12, 2021 at 11:07
  • eduroam typically requires you to use their DNS servers. Also, keep in mind that ping and DNS use completely different protocols and methods of communication at the network level, so it's not unusual to see some networks block access to unauthorized DNS services - talk to your helpdesk for assistance.
    – Thomas Ward ♦
    Sep 13, 2021 at 0:42
  • Try the dig command (eg. dig google.com) and post the output?
    – Eric Power
    Sep 13, 2021 at 3:23
  • dig produces no output for several seconds, and then say ; <<>> DiG 9.16.1-Ubuntu <<>> google.com ;; global options: +cmd ;; connection timed out; no servers could be reached
    – Ge Zhang
    Sep 13, 2021 at 4:46
  • If you need to find the DNS server of your uni but can't contact the IT support for some reason -- here's a trick: Try connecting on your phone, and let it display which dns server it's using (this even works on iphone).
    – Aaron Wild
    Sep 16, 2021 at 15:36

1 Answer 1

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The next step in troubleshooting is to contact the eduroam WIFI helpdesk and ask them whether they are blocking DNS requests to external resolvers, and which DNS resolver you are supposed to use while on their network.

Rationale: It is quite common for educational institutions to limit the acceptable use of their network and to enforce this on the DNS level. In order to enforce this, they need to force their users to go through their DNS server for name resolution.

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  • I seem to have a different problem. I brought another Windows 10 laptop, and this one works fine on eduroam. Using Windows subsystem for Linux, I was able to run host google.com 8.8.8.8 without problem. I could also find the IPv4 DNS server on the windows laptop, "144.214.2.32", and if I run host google.com 144.214.2.32 on my Linux computer, it too fails.
    – Ge Zhang
    Sep 13, 2021 at 1:50
  • So what did the helpdesk say?
    – Tilman
    Sep 13, 2021 at 11:05

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