Debian/MIPS Jessie doesn't resolve hostnames?
Hi all,
I recently resurrected my old Cobalt Qube 2 server appliance after a
hard drive failed in it. Basically I grabbed another old IDE HDD,
installed it then network booted.
Now there isn't yet installation media for Jessie on the Qube, so I used
the Wheezy installation media to install Debian Wheezy, then updated my
sources.list and did an `apt-get dist-upgrade` to get to Jessie.
The thing I've noticed is that the machine seems to have a hard time
resolving hostnames to IP addresses.
Now:
- It gets its settings via DHCP.
- The machine has a valid IP address.
- The machine has a valid default route.
- The machine has IP addresses for two nameservers in /etc/resolv.conf.
- The machine can ping the said nameservers.
Yet, anything that does a hostname look-up; ping, wget, host, you name
it, it'll sit there for a while, then time out reporting that it cannot
resolve the hostname. Inspite of this, `tcpdump` running on that very
same machine reveals that it *did* get a response.
If I fire up a screen session, in one session I run the following command:
> root@qube:~# tcpdump -n -i eth0 -vvv -s0 port 53
> tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
Now, I open a separate shell and try to ping a host:
> root@qube:~# ping -c 3 www.google.com.au
> ping: unknown host www.google.com.au
Back in the other session, I see this:
> root@qube:~# tcpdump -n -i eth0 -vvv -s0 port 53
> tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
> 18:36:26.274633 IP (tos 0x0, ttl 64, id 45704, offset 0, flags [DF], proto UDP (17), length 63)
> 10.20.30.170.56838 > 10.15.20.1.53: [udp sum ok] 49457+ A? www.google.com.au. (35)
> 18:36:26.292514 IP (tos 0x0, ttl 62, id 17784, offset 0, flags [none], proto UDP (17), length 159)
> 10.15.20.1.53 > 10.20.30.170.56838: [udp sum ok] 49457 q: A? www.google.com.au. 1/4/1 www.google.com.au. [1m
> 30s] A 216.58.220.131 ns: com.au. [1h20m39s] NS w.au., com.au. [1h20m39s] NS y.au., com.au. [1h20m39s] NS z.au.
> , com.au. [1h20m39s] NS x.au. ar: y.au. [55m44s] A 37.209.196.5 (131)
> 18:36:31.281730 IP (tos 0x0, ttl 64, id 42786, offset 0, flags [DF], proto UDP (17), length 63)
> 10.20.30.170.33101 > 10.11.12.254.53: [udp sum ok] 49457+ A? www.google.com.au. (35)
> 18:36:31.301357 IP (tos 0x0, ttl 63, id 34612, offset 0, flags [none], proto UDP (17), length 273)
> 10.11.12.254.53 > 10.20.30.170.33101: [udp sum ok] 49457 q: A? www.google.com.au. 4/4/4 www.google.com.au
> . [3m5s] A 74.125.237.191, www.google.com.au. [3m5s] A 74.125.237.175, www.google.com.au. [3m5s] A 74.125.237.1
> 83, www.google.com.au. [3m5s] A 74.125.237.184 ns: google.com.au. [2d23h28m51s] NS ns3.google.com., google.com.
> au. [2d23h28m51s] NS ns1.google.com., google.com.au. [2d23h28m51s] NS ns4.google.com., google.com.au. [2d23h28m
> 51s] NS ns2.google.com. ar: ns1.google.com. [2d4h20m37s] A 216.239.32.10, ns2.google.com. [1d18h20m58s] A 216.2
> 39.34.10, ns3.google.com. [2d4h20m25s] A 216.239.36.10, ns4.google.com. [1d19h41m21s] A 216.239.38.10 (245)
> 18:36:36.287730 IP (tos 0x0, ttl 64, id 46379, offset 0, flags [DF], proto UDP (17), length 63)
> 10.20.30.170.56838 > 10.15.20.1.53: [udp sum ok] 49457+ A? www.google.com.au. (35)
> 18:36:36.288841 IP (tos 0x0, ttl 62, id 17785, offset 0, flags [none], proto UDP (17), length 159)
> 10.15.20.1.53 > 10.20.30.170.56838: [udp sum ok] 49457 q: A? www.google.com.au. 1/4/1 www.google.com.au. [1m
> 20s] A 216.58.220.131 ns: com.au. [1h20m29s] NS z.au., com.au. [1h20m29s] NS x.au., com.au. [1h20m29s] NS y.au.
> , com.au. [1h20m29s] NS w.au. ar: y.au. [55m34s] A 37.209.196.5 (131)
> 18:36:41.293782 IP (tos 0x0, ttl 64, id 43964, offset 0, flags [DF], proto UDP (17), length 63)
> 10.20.30.170.33101 > 10.11.12.254.53: [udp sum ok] 49457+ A? www.google.com.au. (35)
> 18:36:41.294541 IP (tos 0x0, ttl 63, id 34613, offset 0, flags [none], proto UDP (17), length 273)
> 10.11.12.254.53 > 10.20.30.170.33101: [udp sum ok] 49457 q: A? www.google.com.au. 4/4/4 www.google.com.au. [2m55s] A 74.125.237.184, www.google.com.au. [2m55s] A 74.125.237.191, www.google.com.au. [2m55s] A 74.125.237.175, www.google.com.au. [2m55s] A 74.125.237.183 ns: google.com.au. [2d23h28m41s] NS ns1.google.com., google.com.au. [2d23h28m41s] NS ns3.google.com., google.com.au. [2d23h28m41s] NS ns4.google.com., google.com.au. [2d23h28m41s] NS ns2.google.com. ar: ns1.google.com. [2d4h20m27s] A 216.239.32.10, ns2.google.com. [1d18h20m48s] A 216.239.34.10, ns3.google.com. [2d4h20m15s] A 216.239.36.10, ns4.google.com. [1d19h41m11s] A 216.239.38.10 (245)
> 18:36:46.300942 IP (tos 0x0, ttl 64, id 46405, offset 0, flags [DF], proto UDP (17), length 71)
> 10.20.30.170.55271 > 10.15.20.1.53: [udp sum ok] 37564+ A? www.google.com.au.office.network. (43)
> 18:36:46.302062 IP (tos 0x0, ttl 62, id 17786, offset 0, flags [none], proto UDP (17), length 121)
> 10.15.20.1.53 > 10.20.30.170.55271: [udp sum ok] 37564 NXDomain* q: A? www.google.com.au.office.network. 0/1/0 ns: office.network. [1m] SOA office.network. network.admin.office.network. 2015050700 60 900 300 300 (93)
> 18:36:51.307824 IP (tos 0x0, ttl 64, id 46316, offset 0, flags [DF], proto UDP (17), length 71)
> 10.20.30.170.35718 > 10.11.12.254.53: [udp sum ok] 37564+ A? www.google.com.au.office.network. (43)
> 18:36:51.311954 IP (tos 0x0, ttl 63, id 34614, offset 0, flags [none], proto UDP (17), length 121)
> 10.11.12.254.53 > 10.20.30.170.35718: [udp sum ok] 37564 NXDomain* q: A? www.google.com.au.office.network. 0/1/0 ns: office.network. [1m] SOA office.network. network.admin.office.network. 2015050700 60 900 300 300 (93)
> 18:36:56.313777 IP (tos 0x0, ttl 64, id 47925, offset 0, flags [DF], proto UDP (17), length 71)
> 10.20.30.170.55271 > 10.15.20.1.53: [udp sum ok] 37564+ A? www.google.com.au.office.network. (43)
> 18:36:56.314861 IP (tos 0x0, ttl 62, id 17787, offset 0, flags [none], proto UDP (17), length 121)
> 10.15.20.1.53 > 10.20.30.170.55271: [udp sum ok] 37564 NXDomain* q: A? www.google.com.au.office.network. 0/1/0 ns: office.network. [1m] SOA office.network. network.admin.office.network. 2015050700 60 900 300 300 (93)
> 18:37:01.319846 IP (tos 0x0, ttl 64, id 47619, offset 0, flags [DF], proto UDP (17), length 71)
> 10.20.30.170.35718 > 10.11.12.254.53: [udp sum ok] 37564+ A? www.google.com.au.office.network. (43)
> 18:37:01.320533 IP (tos 0x0, ttl 63, id 34615, offset 0, flags [none], proto UDP (17), length 121)
> 10.11.12.254.53 > 10.20.144.170.35718: [udp sum ok] 37564 NXDomain* q: A? www.google.com.au.office.network. 0/1/0 ns: office.network. [1m] SOA office.network. network.admin.office.network. 2015050700 60 900 300 300 (93)
So it didn't get a reply just once, but 7 times, from both name servers.
Yet the C library seems to be deaf. There is no firewall in place
anywhere on the machine itself or anywhere en route to the DNS servers.
I get the same problem if I force it to use 8.8.8.8 as a nameserver too.
For the record: package versions…
> root@qube:~# dpkg -l libc6
> Desired=Unknown/Install/Remove/Purge/Hold
> | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
> |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
> ||/ Name Version Architecture Description
> +++-=====================-===============-===============-================================================
> ii libc6:mipsel 2.19-18 mipsel GNU C Library: Shared libraries
> root@qube:~# uname -a
> Linux qube 3.2.0-4-r5k-cobalt #1 Debian 3.2.68-1+deb7u1 mips GNU/Linux
Has anyone seen this behaviour and/or have any ideas what I might do to
solve this problem?
Regards,
--
Stuart Longland (aka Redhatter, VK4MSL)
I haven't lost my mind...
...it's backed up on a tape somewhere.
Reply to: