On 2004-01-07, Geoff <geoff_r@canada.com> wrote:
> Setup:
> WAN
> |
> 3Com <--> Router <--> Other PC
This is unclear. Is the 3Com connected to the Router, or to the WAN, or
is the WAN, Router, and 3Com connected to the same switch/hub? Is 3Com
supposed to be another router?
Please supply more topology information (IP addresses, connection info,
routes, subnet information.)
> Output of "ping 172.16.37.15" (PC connected to router)
> ---------------------------------------------------------------
> PING 172.16.37.15 (172.16.37.15) 56(84) bytes of data
> From 172.16.37.20 icmp_seq=1 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=2 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=3 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=4 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=5 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=6 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=7 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=8 Destination Host Unreachable
> From 172.16.37.20 icmp_seq=9 Destination Host Unreachable
> CNTRL-C
> ---- 172.16.37.15 ping statistics ---
> 12 packets transmitted , 0 received, +9 errorrs, 100% packet loss,
> time 11077ms, pipe 3
> ---------------------------------------------------------------
From this I can tell two things. First, packet's are going out, but
something (most likely the Router) is saying that the host is
unreachable. (Although the output of 'ifconfig -a eth0' would seem to
indicate that there is nothing coming in, so the sending host must be
realising that itself (such as a routing problem). The total time would
indicate that its not being delayed significantly.
> Output of ifconfig -a eth0 has the following :
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:16 errors:0 dropped:0 overruns:0 frame:0
> Contents of /proc/interrupts: (just line 5 and last 2)
> ---------------------------------------------------------------
> 5: 0 XT-PIC eth0
> NNT: 0
> ERR: 0
Further indication that its not receiving anything off the wire.
> netstat -r gives the following :
> ---------------------------------------------------------------
[reformatted]
> Destination Gateway Genmask Iface
> 172.16.37.0 * 255.255.255.0 eth0
> 169.254.0.0 * 255.255.0.0 eth0
> 127.0.0.0 * 255.0.0.0 lo
> default 172.16.37.254 0.0.0.0 eth0
> ---------------------------------------------------------------
Hmm, one wishes that you would list the IP addresses and routing tables
of all the machines involved. One possible reason for not receiving
anything back is that the route-back is not set, or is set incorrectly.
BTW, '/sbin/route -n | cut -b-48,72-' gives something easier to look at
in a post.
> I have no clue why 169 is there... I did remove it after a previous
> install with no differences
I think I may be able to explain the 169. Microsoft gives its
unconfigured devices numbers in that range, so that unconfigured devices
can be found (and configured, one would assume).
You should also make sure that the Router is set to forward IP.
'cat /proc/sys/net/ipv4/ip_forward' should output 1.
You might also try employing tcpdump on the router if you can to make
sure that its receiving anything. This should tell you plenty about
what's going on.
--
Cameron Kerr
cameron.kerr@paradise.net.nz :
http://nzgeeks.org/cameron/
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