0

I have a fresh install of Ubuntu 16.04.1 LTS (I don't think this matters, but I did apt install ubuntu-gnome-desktop after the initial install) and I have inexplicable problems with DNS resolution and after piles of searching I haven't seen this exact problem described anywhere. After the OS boots, resumes, or changes network, DNS resolution does work, but only for simple commands like ping and nslookup. Most other services like curl, ssh, and web browsers like chrome or firefox fail entirely (that is, time out without successfully resolving the host name). Here's an example.

Ping and nslookup both work:

root@myhostname:/etc/avahi# nslookup github.com
Server:     8.8.8.8
Address:    8.8.8.8#53
Non-authoritative answer:
Name:   github.com
Address: 192.30.253.112
Name:   github.com
Address: 192.30.253.113
root@myhostname:/etc/avahi# ping github.com
PING github.com (192.30.253.112) 56(84) bytes of data.
64 bytes from 192.30.253.112: icmp_seq=1 ttl=55 time=21.5 ms
64 bytes from 192.30.253.112: icmp_seq=2 ttl=55 time=28.0 ms
^C
--- github.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 21.527/24.797/28.068/3.274 ms

But if I curl immediately after it fails:

root@myhostname:/etc/avahi# curl github.com
curl: (6) Could not resolve host: github.com

I've disabled dnsmasq in NetworkManager. I've tried disabling IPV6. I've tried various changes I've read online regarding avahi settings. All to no avail. One poster went so far as to say "systemd is a mess, you're best off to just reinstall until you get it working".

Here's the kicker, though. Some time later if I leave it alone, it does start to work. Maybe 5-15 minutes later everything magically works. Does anybody have any idea how to resolve this? Thank you.

Michael Litherland
  • 1
  • 3

1 Answers1

0

Edit:

After trying to cajole the Killer 1535 into working reliably for months I gave up, bought an Intel 7265NGW, which is a drop in replacement and works perfectly. There are guides online to replacing the Wifi adapter in this machine and the Intel part is available on various online sources for less than 20 USD. Well worth getting rid of that headache.

Previous comment:

Apparently the drivers for Killer 1535 Wifi card were causing my problems with intermittent odd behavior like I described above. Dell recommends running the very latest kernels with this machine, so I opted to switch to Gnome Ubuntu 16.10 and I haven't had any problems whatsoever since then. There are ways of upgrading the kernel for the LTS releases, but I try not to deviate too much from a base install in case of running into other problems that are hard to diagnose. Thanks to anybody who may have taken a look at my problem, and especially @Elder Geek for the hints.

Michael Litherland
  • 1
  • 3