Gidday all. I'm going to describe a problem that I was having with my
work machines, and I'm going to see who comes closest to the correct
answer to the problem (which took three days to solve)
I have a Ppro 166 doing firewall duties. It has eth0, 192.168.1.1 with
netmask of 255.255.0.0 for internal, and eth1, 202.0.37.196 /
255.255.255.0 for the cablemodem side. On the firewall, ping works fine
to internet hosts, localhost, and internal hosts. It is runningf 2.4.19
with an iptables firewall script.
Internally there is a machine called belt, which is the main linux box.
It runs bind9, squid, exim, and samba. belt has two nics
eth0 Link encap:Ethernet HWaddr 00:02:E3:16:7F:FE
inet addr:192.168.1.2 Bcast:192.168.255.255 Mask:255.255.0.0
eth1 Link encap:Ethernet HWaddr 00:02:E3:15:D4:CB
inet addr:192.168.1.12 Bcast:192.168.255.255 Mask:255.255.0.0
eth0 is bound to squid and other IP related stuff, eth1 is used for
samba and windowsie stuff. Both NICs are plugged into the same 100 Mbit
switch.
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.0.0 U 0 0 0 eth1
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
SYMPTOMS:
belt:~# time host www.google.com
Nameserver not responding
www.google.com No A record found
0.000u 0.000s 0:15.00 0.0% 0+0k 0+0io 132pf+0w
belt:~# ping 203.96.152.4 <-- paradise nameserver
PING 203.96.152.4 (203.96.152.4): 56 data bytes
64 bytes from 203.96.152.4: icmp_seq=12 ttl=252 time=10.8 ms
64 bytes from 203.96.152.4: icmp_seq=13 ttl=252 time=9.4 ms
64 bytes from 203.96.152.4: icmp_seq=14 ttl=252 time=11.8 ms
64 bytes from 203.96.152.4: icmp_seq=15 ttl=252 time=10.8 ms
64 bytes from 203.96.152.4: icmp_seq=16 ttl=252 time=10.5 ms
64 bytes from 203.96.152.4: icmp_seq=17 ttl=252 time=10.9 ms
64 bytes from 203.96.152.4: icmp_seq=18 ttl=252 time=10.4 ms
64 bytes from 203.96.152.4: icmp_seq=19 ttl=252 time=10.3 ms
64 bytes from 203.96.152.4: icmp_seq=48 ttl=252 time=10.3 ms
64 bytes from 203.96.152.4: icmp_seq=49 ttl=252 time=10.3 ms
64 bytes from 203.96.152.4: icmp_seq=50 ttl=252 time=10.1 ms
64 bytes from 203.96.152.4: icmp_seq=51 ttl=252 time=9.9 ms
64 bytes from 203.96.152.4: icmp_seq=52 ttl=252 time=10.0 ms
64 bytes from 203.96.152.4: icmp_seq=53 ttl=252 time=10.4 ms
...
that is, missing about 12, getting about 12, missing 40, getting 12...
etc
All internal pinging from belt works fine. What seems to be the
problem?
