[vox-tech] Re: troubleshooting internet connection

[vox-tech@lists.lugod.org]

On Fri, Jan 24, 2003 at 01:58:07PM -0800, Robin Snyder wrote:
> > > My setup: I'm on a fixed IP address, using a DSL line.  I have two
> > > ethernet cards.
> 
> >   From what I remember seeing done to your computer nothing _should_
> > have changed it's network behavior... except possibly when a dhcp
> > client was installed.
> 
> >   Besides the X server, possibly dhcp client, apt-get dist-upgrade...
> > are there any other things you remember being done to your machine?
> 
> We switched to an ext3 filesystem, but I can't see why that would
> change anything.  I'm now regularly using kernel 2.4.18, and that may
> be it.  (I had LinuxOLD (= 2.2.x) as my default previously.)  

  Ahh yes... a kernel recompile could very easily be causing problems.
I forgot that was done.

> Is it
> possible that the firewall/something with ipchain could be messing
> things up?

  Yes... ipchains is meant for the 2.2 kernel series, iptables is
for the 2.4... it's very likely that something firewall related is
causing problems.

> > this is a list of the commands I would like to see run on that machine:
> > ====
> > route -n
> 
> Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
> 0.0.0.0         168.150.243.1   0.0.0.0         UG    0      0        0 eth0

  this is your default route... going out eth0 and using 168.150.243.1
as the gateway.

> > ipchains -L -n
> 
> ipchains: Incompatible with this kernel

oh yes, 2.4.... please run:
  iptables -L -n -v

> > ifconfig
> 
> eth0      Link encap:Ethernet  HWaddr 00:10:4B:96:E8:A8
>           inet addr:168.150.243.52  Bcast:168.150.243.255  Mask:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:2089 errors:0 dropped:0 overruns:0 carrier:2089
>           collisions:0 txqueuelen:100
>           RX bytes:0 (0.0 b)  TX bytes:204356 (199.5 KiB)
>           Interrupt:9 Base address:0xdc00

  something is odd about this... it seems to be transmitting a bunch,
but there are no receives.  The carrier errors are odd too... but I'm
certain that we used eth0 at the installfest with that new kernel.

> > one of:
> >   mtr -n -c 3 -r  169.237.104.199

that was an IP address of www.ucdavis.edu... so you certainly have some
a valid network connection.

  Can you also run "ifconfig eth0" _after_ running the mtr from above...
I would expect to see RX bytes increment... if you don't see the count
go up, then can you run "lsmod" and display the output.  I think there
are two available drivers for your ethernet card... both were compiled
as modules so we can switch to the other one very easily.  we may
want to try that if the iptables command above doesn't show anything
exciting.

    TTFN,
      Mike