On Tue, 06 Apr 2004 10:44:20 -0700, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote:

>On Tue, 06 Apr 2004 09:17:31 +1200, David Kirk
><davidrkirk.NOSPAM@hotmail.com> wrote:
>
>>All of this is happening on our local LAN. Both subnets are on the
>>same piece of wire, but of course they won't talk to each other
>>without the router. There are no WAN links or Internet involved.
>
>Now you tell me. This is what threw me:
>"The router at the default gateway (192.168.1.251) is a Cisco 1721 set
>up to pass all traffic between the two subnets."
>Lacking any info on the topology, I just assumed that you were
>routeing between two subnets over the internet. Grumble...

The first sentence in this thread was "We are migrating our network
from a 192.100.100.0 subnet to a 192.168.1.0 subnet and I am having
problems with our SCO 5.0.4 boxes.". I guess I didn't make it clear
that I wasn't moving the network, but just re-addressing it. Sorry.

>Don't forget the WINS cache, NETBIOS name cache, various HOSTS and
>LMHOSTS files, etc. Yeah, great idea. I've done it that way and
>managed to "forget" necessary changes. The problem is that everything
>had to get fixed twice. Once to get the multi-address configuration
>to play, and once again when I had to get rid of it. Is there a
>reason you can't just change everything at once? Why prolong the
>ordeal?

We are open for business 24 hours per day, 7 days per week. We only
close for Good Friday (in 2 days), ANZAC day and Christmas day. I
don't plan on breaking everything on Friday and trying to fix multiple
systems over the rest of the weekend (when I probably won't be able to
get vendor support).

>I vaguely recall that there was some kind of bug in the alias
>mechanism in 3.2v5.0.4 that was later fixed. I'll dig when I get to
>the office (timer permitting).

It seems to be working fine for me.

>>The JetDirect is still set to use DHCP. The address hasn't changed
>>since the printer was installed. When I move it to the other subnet
>>it will have a static address.
>
>Well, if it's currently set for DHCP, are you sure that it has the
>right address? My nightmare was having multiple DHCP servers running
>on a LAN. It happens almost every time someone tinkers with a
>wireless router. I have arpwatch running to detect such problems on
>mission critical networks. Lately, I've been using "static DHCP" to
>assign IP addresses to print servers. The idea is to build a table of
>MAC address and IP address pairs in the router that's running DHCP,
>and reserve the IP's for those devices. I haven't figured out an
>effective backup scheme in case the DHCP server dies, but that hasn't
>been much of a problem with long lease times.

Yep. I just checked it.

>>Unfortunately (?) I can't test it at the moment because it all works
>>and I don't know how to replicate the fault other than wait until
>>tomorrow morning :-( I can answer some of them from my previous
>>testing though.
>
>Well, if it's intermittant, then it's probably the RIP1 (routed)
>problem. That means you have a router or server on your LAN that's
>spewing RIP announcements. Find and disable. It will break other
>devices.

I have disabled routed as you suggested earlier.

>>There is only 1 router with 2 interfaces (1 for each subnet).
>
>With every IP port transparently routed between both networks?
>
>>Yes, very logical. I will have another go at this next time it fails.
>>Because it is the SCO box that is the problem though, I think I should
>>probable see what I can ping from the SCO box. Eg. localhost, another
>>host on same subnet, router local interface, router remote interface,
>>host on other subnet. That should more accurately find the fault.
>
>Yep. The pattern should be obvious. I still think there's some
>obscure file on the OSR5 boxes that haven't had their IP address
>tweaked. I know you said you checked everything, but I'm still
>suspicious.

I came in this morning, went to the server and tried to ping the
printer. It didn't respond.

I pinged another server on the 192.168.1.0 subnet and got a response.

I pinged both interfaces of the router and got responses.

I pinged other hosts on the 192.100.100.0 subnet and got responses.

I telnetted to the router and pinged the printer and got no response.

This proves the problem is not with the SCO boxes, but with the
router. Sorry to waste your time, but I learnt heaps and cleaned up a
few things on my SCO boxes.

Thanks for all your help. Now I will have to figure out what is wrong
with the router.


Later

David Kirk