Mailinglist Archive: opensuse-edu (132 mails)

[Michael Brown <mbrown@xxxxxxxxxxxxxxxx>]

On Tue, 25 Jun 2002, Steve Palmer wrote:
> Sorry about the delay, i've been busy with a few
> things. Anyway heres the info:

> eth0 Link encap:Ethernet  HWaddr 00:00:E8:8B:7E:66
> inet addr:192.168.3.200  Bcast:192.168.3.255  Mask:255.255.252.0

OKish.

> eth1 Link encap:Ethernet  HWaddr 00:90:27:73:DB:FC
> inet addr:10.0.40.2  Bcast:10.0.41.255  Mask:255.255.254.0

OK.  Who chose these subnet masks, btw?

> PING 192.168.3.200 (192.168.3.200) from 192.168.3.200 : 56(84) bytes of data.
> 64 bytes from 192.168.3.200: icmp_seq=1 ttl=255 time=0.180 ms

Proves that eth0 interface is working, but proves nothing about routing to
192.168.0.0/255.255.252.0 network.

> PING 192.168.3.201 (192.168.3.201) from 192.168.3.200 : 56(84) bytes of data.
> From 192.168.3.200: icmp_seq=1 Destination Host Unreachable

Suggests a dead host.  A routing problem would show up as
"connect: Network is unreachable"

> PING 10.0.40.2 (10.0.40.2) from 10.0.40.2 : 56(84) bytes of data.
> 64 bytes from 10.0.40.2: icmp_seq=1 ttl=255 time=0.137 ms

Again, proves that eth1 is working but doesn't say anything about state of
routing to 10.0.40.0/255.255.254.0

> PING 10.0.40.1 (10.0.40.1) from 10.0.40.2 : 56(84) bytes of data.
> From 10.0.40.2: icmp_seq=1 Destination Host Unreachable

Suggests a dead host, as before.

> Kernal IP Routing Table
> Destination Gateway   Genmask       Flags Iface
> 10.0.40.0   0.0.0.0   255.255.254.0 U     eth1
> 192.168.0.0 0.0.0.0   255.255.252.0 U     eth0
> 0.0.0.0     10.0.40.1 0.0.0.0	      UG    eth1

Routing looks OK, assuming that 10.0.40.1 is the IP address of your
default gateway.

Are you *sure* that you have the physical network cables plugged in the
right way round (as in eth0->192.168.0.0 network, eth1->10.0.40.0
network)?  Are you also sure that the hosts you are pinging (192.168.3.201
and 10.0.40.1) are alive and able to communicate with the rest of the
network?

You could try running

tcpdump -i eth0 -n

and

tcpdump -i eth1 -n

to observe traffic coming to both network cards.  This should show you if
you have got the wires mixed up.

As a final check: do you have any firewalling (ipchains/iptables) rules
set up?

Michael Brown
http://www.fensystems.co.uk
--
Fen Systems: Linux made easy for schools