Subject: Network problems; no name lookups, no real connection?
To: None <email@example.com>
From: Jan Danielsson <firstname.lastname@example.org>
Date: 02/02/2006 15:03:17
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On a system I administrate remotely, I can no longer look up host
names. Actually, the problems seem to be bigger than that.
First of all, there are two systems, both running NetBSD. The once
causing my grief, I'll call A, and the other one, which is physically
located 2 cm from A, I'll call B.
A and B are connected to the internet via a cablemodem + DHCP. They
are also connected via an internal network (which I used to be able to
reach A (through B).. It has changed it's public IP, but due to the
problems I'm about to describe, that announcement never reached me).
This is on system A:
# ping www.uu.se
ping: Cannot resolve "www.uu.se" (Host name lookup failure)
On system B:
$ ping www.uu.se
PING www.uu.se (184.108.40.206): 56 data bytes
64 bytes from 220.127.116.11: icmp_seq=3D0 ttl=3D245 time=3D52.342 ms
64 bytes from 18.104.22.168: icmp_seq=3D1 ttl=3D245 time=3D44.546 ms
64 bytes from 22.214.171.124: icmp_seq=3D2 ttl=3D245 time=3D49.839 ms
Now back to system A again; let's assume that it's only the host name
lookup that is failing:
# ping -n 126.96.36.199
PING 188.8.131.52 (184.108.40.206): 56 data bytes
... it just sits there doing nothing, until I break. So, obviously
we're not getting very far. Let's review the routing table on A:
# route show
Destination Gateway Flags
default 220.127.116.11 UG
18.104.22.168/18 link#1 U
22.214.171.124 00:b0:c2:3c:7c:00 UH
126.96.36.199 127.0.0.1 UGH
188.8.131.52 127.0.0.1 UGH
loopback 127.0.0.1 UGR
localhost 127.0.0.1 UH
192.168.0.0/24 link#2 U
And try to ping A's gateway:
# ping 184.108.40.206
PING 220.127.116.11 (18.104.22.168): 56 data bytes
64 bytes from 22.214.171.124: icmp_seq=3D0 ttl=3D255 time=3D33.267 ms
64 bytes from 126.96.36.199: icmp_seq=3D1 ttl=3D255 time=3D32.393 ms
64 bytes from 188.8.131.52: icmp_seq=3D2 ttl=3D255 time=3D33.481 ms
I also checked the netmasks on the external interfaces for systems A
and B, and they match (they are assigned by the dhcp).
As I stated earlier, A and B and physically next to each other, and
they share the same cable modem, the same dhcp, same isp, etc. I tried
disabling the firewall, but that didn't change anything.
I know absolutely nothing about networking, but I feel like blaming
the isp for something. Anyone know what could be wrong? Any suggestions
what I should try?
Te audire non possum. Musa sapientum fixa est in aure.
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