[SWLUG] networking nightmare

Dave Cridland [Home] dave at cridland.net
Fri Apr 11 09:30:35 UTC 2003


On Thu, 2003-04-10 at 20:10, Rhys Sage wrote:
> >You said Windows tried to get a DUN connection when you tried to ping
> >your linux machine. This suggests Windows doesn't know how to
> >communicate with the Linux machine.
> 
> With a ping via RJ45, I get 100% loss. I suspect something's not set quite
> right on my laptop or my PC. I'll try to bring my laptop to the next meet.
> Just checking - it is the Goose in Swansea on the 17th at 7pm?

16th (Wednesday).

> >What are your IP addresses set to, both on the Linux machine and the
> >Windows machines? You can get these values via:
> >Linux: /sbin/ifconfig and /sbin/route
> >Windows: it's either "ipconfig" or "ifconfig", I don't remember (or
> >just
> >use the network settings GUI) and "route print" to get the routing
> >table.
> 
> Here's a paste of winipconfig and the settings from SME Linux.
> 
>                  From the MSDos prompt
> 
>                   Microsoft(R) Windows 98
>                   (C)Copyright Microsoft Corp 1981-1998.
> 
>                   C:\AWKWARD>ipconfig -all
> 
>                   Windows 98 IP Configuration
> 
>                   Host Name . . . . . . . . . : PERSIUS
>                   DNS Servers . . . . . . . . : 195.92.195.95
>                   195.92.195.94
>                   Node Type . . . . . . . . . : Broadcast
>                   NetBIOS Scope ID. . . . . . :
>                   IP Routing Enabled. . . . . : No
>                   WINS Proxy Enabled. . . . . : No
>                   NetBIOS Resolution Uses DNS : No
> 
>                   0 Ethernet adapter :
> 
>                   Description . . . . . . . . : PPP Adapter.
>                   Physical Address. . . . . . : 44-45-53-54-00-00
>                   DHCP Enabled. . . . . . . . : Yes
>                   IP Address. . . . . . . . . : 217.134.47.212
>                   Subnet Mask . . . . . . . . : 255.255.255.0
>                   Default Gateway . . . . . . : 217.134.47.212
>                   DHCP Server . . . . . . . . : 255.255.255.255
>                   Primary WINS Server . . . . :
>                   Secondary WINS Server . . . :
>                   Lease Obtained. . . . . . . : 01 01 80 00:00:00
>                   Lease Expires . . . . . . . : 01 01 80 00:00:00
> 
>                   1 Ethernet adapter :
> 
>                   Description . . . . . . . . : 3Com EtherLink PCI
>                   Physical Address. . . . . . : 00-50-04-36-AB-00
>                   DHCP Enabled. . . . . . . . : Yes
>                   IP Address. . . . . . . . . : 169.254.72.239
>                   Subnet Mask . . . . . . . . : 255.255.0.0

Note: 169.254/16 network. Auto configuration?

>                   Default Gateway . . . . . . :
>                   DHCP Server . . . . . . . . : 255.255.255.255

Ah, all ones DHCP Server - more autoconf evidence, I think.

>                   Primary WINS Server . . . . :
>                   Secondary WINS Server . . . :
>                   Lease Obtained. . . . . . . : 04 06 03 20:58:07
>                   Lease Expires . . . . . . . :

Ah, 3Com Etherlink, old one. I think these require explicit
configuration of what media to use. Certainly the older, ISA, Etherlinks
did, and I don't think there was much changed. There's a configuration
tool on the driver disk, or else you can see whether there's anything in
the settings in the Control Panel, but I haven't the first idea of where
to look on a Windows box.

At the moment, Windows has flipped into "dynamic autoconfiguration mode"
for addressing, which essentially means "pick a random IP address and
{see if/hope} it works in some respect".

The usual reasons for this are:

1) It's not physically connected to the network. (Duff cable, no cable,
wrong cable).
2) It is, but it's configured not to use it.
3) It is, but it cannot find a DHCP server.

Given the information below, I suspect (2) - specifically, the card is
configured to use the 10base2 media, which isn't plugged in, because
you're using 10baseT instead.

If the network card on the Windows machine were, in fact, working on
10baseT media, it would most likely see the Linux box's DHCP server, and
acquire an IP address that way.

Of course, I could be wrong, but this seems to fit the facts. (As does
using crossover cables, but I find that unlikely given that they were
bought with the hub - nobody would sell crossovers with a hub, would
they?).

>                   From the Configuration window
> 
>                   Ethernet settings
>                   Ethernet driver 1: Tulip
>                   Ethernet driver 2:
> 
>                   External network settings
>                   Operation mode: Server only - dedicated
>                   Gateway IP address: 192.168.40.1
> 
>                   Local network settings
>                   Local IP address: 192.168.40.1
>                   Local subnet mask: 255.255.255.0

Note: 192.168.40/24

>                   DHCP server: enabled, using host numbers from
> 192.168.40.65 to
>                   192.168.40.250

Note: DHCP server active, using apparently sane range.

> 
>                   Miscelleneous settings
>                   Primary domain name: Sageworld
>                   system name: zeus
>                   external proxy : no
>                   status reports: off
>                   console mode: auto
> 
>                   contact details
>                   contact email:
>                   contact name:
>                   contact organisation:
> 
> I hope that all makes sense to somebody. BTW I was online to the internet
> when I did the ipconfig. Zeus is never online - it doesn't have a modem.
> 
> >Let me know if you don't know what I'm talking about here and I'll give
> >you some values you can fill in.
> 
> I'm just guessing that the above is what you asked for.

It was roughly what was asked for. Good enough, anyway.

> >I'm guessing your windows machines haven't been given IP addresses for
> >your network cards - they only use TCP/IP for their internet (modem)
> >connection. This would explain why windows can see windows yet the
> >linux box is unpingable.
> 
> No. I haven't set any I/P addresses. I can't ping the Linux box when I'm
> using BNC because BNC connects solely Aphrodite to Persius. Zeus needs RJ45
> and as I gather RJ45 and BNC don't mix, it's a case of either Persius being
> connected to Aphrodite via BNC or Persius, Zeus and Aphrodite being
> connected by RJ45 to the hub.

RJ45 and BNC (or 10baseT and 10base2) do mix, but you need a hub to sit
in between and translate (Actually "transceive") between the two. If
your hub supports 10base2, you can do this now. (Actually you can buy
seperate transceivers, but they're probably more expensive than hubs,
these days. I've got a couple of AUI->10baseT ones, mind.)

But frankly, 10base2 is a pain anyway. I find it desperately prone to
random errors on anything with more than a couple of nodes.

> >Let us know how you get on :)
> 
> Somebody said that the problem might be in Network Neighbourhood in the
> configuration panel. Any ideas exactly what I should have there? At the
> moment, I have:
> Client for Microsoft Networks
> Client for NetWare Networks
> 3com etherlink pci combo nic (3c900b-combo)

Perhaps fiddle here to change "media type" or "transceiver type". You're
looking for "10baseT", "RJ45", or "Cat5", most probably the first.

> dial-up adaptor
> ipx/spx-compatible protocol -> 3com etherlink pci combo nic (3c900b-combo)
> ipx/spx-compatible protocol -> dial-up adaptor
> netbeui -> 3com etherlink pci combo nic (3c900b-combo)
> netbeui -> dial-up adaptor
> tcp/ip dial-up adaptor

Is there really no "tcp/ip -> 3com etherlink pci combo nic
(3c900b-combo)"? I'd have thought there should be.

> file & printer sharing for microsoft networks
> 
> primary network login - windows login

Summary:

My guess is that this is not a Linux problem, but a one on the Windows
machines relating to the ethernet cards.

It's made overcomplicated by Windows not reporting what it has, in fact,
chosen to do.

An alternative solution:

Bring along your hub (and its PSU), and I'll bring along my spare hub,
which has a BNC port hanging off the back, and we can swap, so you can
just add it as a node to your existing 10base2 network, and plug the
Linux box into it as normal. I'll bring you a spare, known working,
straight cat5 cable you can try, as well.

Let me know, I'll need to dig the thing out and figure out which PSU is
its.

Dave.





More information about the Swlug mailing list