On Mon, 3 Mar 1997, Steve Izma wrote:
> I've been setting up Debian 1.2.4 (25 Jan.: Cheapbytes distribution)
> on two new Pentium 150 systems and I can't get network routing over
> ethernet to work.
>
> Installation of netbase and netstd seemed to go well using dselect,
> except for an unsurprising temporary problem in finding the right i/o
> port for the ethernet card. I'm using the D-link DE220P, which the ne
> driver easily finds. Ifconfig gives this report, which I believe shows
> correct configuration of the driver to the card:
>
> eth0 Link encap:10Mbps Ethernet HWaddr 00:80:C8:2D:7D:8F
> inet addr:192.54.242.228 Bcast:192.54.242.255 Mask:255.255.255.0
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0
> TX packets:4117 errors:0 dropped:0 overruns:0
> Interrupt:11 Base address:0x220
>
> Pinging the localhost works fine, but pinging anything else on the
> network (even the immediately adjacent device connected via coax)
> produces no result. I'm sure it's not a wiring problem because the
> rest of the machines on the network are not affected and I get the
> same negative results using ping on both new machines, which are wired
> into the network in different locations in the office.
does the card have more than one connector? i.e. BNC and/or RJ-45 and/or
AUI connectors?
If so, make sure that the card is correctly configured to use the right
connector for your network.
4117 TX packets and 0 RX packets makes me a bit suspicious that, e.g., the
card is configured to use the RJ-45 UTP connector when you are running on a
coax network - or vice-versa.
check the output of 'dmesg' (or 'tail /var/log/messages') - cabling
problems like this usually show error messages in the logs.
> Trying ftp produces the error: "no route to host".
> So I assume this is some sort of routing problem.
no, it's not routing. you get that same 'no route to host' message when
your computer can't figure out a host's ethernet address using arp. to
send a packet to a host on the local ethernet, your machine will send
out an 'arp who-has' request and wait for an 'arp is-at' reply. This builds
up the kernel's arp table so it knows which hosts (ethernet cards, actually)
correspond to which IP addresses.
here's an example of what happens - excerpt of output from tcpdump:
# tcpdump -l | grep arp
09:47:52.279492 arp who-has taz.net.au tell proxy.taz.net.au
09:47:52.279492 arp who-has siva.taz.net.au tell proxy.taz.net.au
09:47:52.279492 arp reply siva.taz.net.au is-at 0:0:c0:a:44:a5
09:47:52.279492 arp reply taz.net.au is-at 0:0:c0:5:c3:14
.
.
09:48:01.741658 arp who-has kali.taz.net.au tell siva.taz.net.au
09:48:01.741658 arp reply kali.taz.net.au is-at 0:0:c0:bc:2f:41
and this is part of what the arp table looks like on siva:
# arp -a
Address HWtype HWaddress Flags Mask Iface
taz.net.au ether 00:00:C0:05:C3:14 C * eth0
kali.taz.net.au ether 00:00:C0:BC:2F:41 C * eth0
proxy.taz.net.au ether 00:00:C0:9F:96:42 C * eth0
if your machine is sending out the arp who-has request and doesn't get
the arp reply then it will be unable to send a packet to the target host.
my guess is that it is unable to get the arp 'is-at' reply because it is
using the wrong connector. you say your network is coax...make sure that
the card is using the BNC connector and NOT an AUI or RJ-45 connector.
Depending on the type of card you have, you may have to configure this by
setting jumpers on the card. Some cards can be set up with ms-dos based
configuration programs. Some cards even have linux config tools. Some
newer cards can auto-detect whether the network is coax or rj-45.
> The problem is identical on both machines with the new distribution.
> I've compared everything I can think of to another machine we have
> running Debian 1.1 (dating from last June). All the files in init.d
> appear to be the same (/etc/init.d/net*). The machine with 1.1 works
> fine.
it looks like a hardware fault or hardware configuration problem to me,
not software.
how many other machines are on the network? do you get any response if you
do a broadcast ping (i.e. ping the broadcast address 192.54.242.255)?
craig
