Can't figure out what's the problem...

[Massimo Nespolo]

.... and can't even find a meaningful subject for this post, sorry.
We have a number of PCs (mainly 2K and XP) conneted to a domain hosted
by a NT4 server. Until recently we had a whole class of IP addresses
(from 0 to 254), and we used 0 for the mask and 254 for the gateway.
Recently, our lab has been divided into two groups/ The first one has
got the assresses from 0 to 128, the second one from 192 to 254. The
intermediate addresses have been assigned elsewhere.
The server belongs to the first group, its parameters are 0 for the
mask and 126 for the gateway. Most PCs in this first group can see all
the neighborhood. I and a few others can see only a subset of 3-4 PCs.
We can "ping" the others, but we neither see them in the network
neighborhood, nor we can reach them by a serach by computer name.
My config is the same as the server: 0 for the mask and 126 for the
gateway. I tried exiting from the domain, rebooting in a workgroup
and rejoining the domain (and rebooting of course). Nothing, I see
always only the subset of 3-4 PCs. As if we formed a restrited
group.
I'm on Win2KProSP4 with nothing left on WinUpdate. Sygate Personal
Firewall 5.5, which however does not interfere (shutting down the
firewall does not solve). NetBEUI and Clients for Microsoft
obviously installed. My account on both the local machine and hte
server have administrative rights.
Any hint in which direction to look further?
Many thanks in advance.

 

[serverguy]

Why netbeui? Get rid of it. Rest sounds like a DNS issue - if you can ping
by ip but not resolve by name - that's usually DNS. Also, do you have
Netbios enabled? File and Printer sharing? You said your have an account on
your machine and the server, but unless you have permissions to the other
pcs, you won't be able to access them. But I don't think that is your
problem since you can't even see them.

 

[mwf]

Massimo,

You've got tcp/ip issues!

With your range of IP addresses "divided", your subnet mask should be
updated also. If you've broken out 129-191, your range has been split into
4 subnets. Your new subnet mask is 255.255.255.192 for each of the 4
subnets.

You cannot use the "all zeros/all ones" addresses, so do not use .0, .63,
..64, .127, .128, .191, .192, or .255, the first and last IP address in each
subnet.

The subnets must now be connected with a router, or device acting as a
router. A Windows 2000 server can act as a router, by installing and
configuring the Routing and Remote Access Service. This machine will also
need to be connected to each subnet - one NIC, with a valid IP address, for
each subnet.

The default gateway in each subnet would be the IP address of the router
that connects that subnet to the rest of the network.

There is an excellent, free, online tutorial on subnetting at
http://www.learntosubnet.com you might want to check out.

Good luck!

Mark Fertig
(e-mail address removed)

 

[Massimo Nespolo]

Mark,
thanks for the link and for the hints and explanations.
What puzzles me is that most of our PCs can see the whole network even if
they have the same subnet mask and gateway as me. What makes things
different?
Also, our NT server was on .64, which is one of the addresses you indicate
as not to be used. Perhaps we should move it. And probably we should
upgrade to Win2KServer to have RRAS. Now I have a good reason to ask my
boss the funds for upgrading the server ;-)
Massimo

 

[Massimo Nespolo]

Why netbeui? Get rid of it.
Done

Rest sounds like a DNS issue - if you can ping
by ip but not resolve by name - that's usually DNS. Also, do you have
Netbios enabled?

This was the problem.

File and Printer sharing?
Yes

You said your have an account on
your machine and the server, but unless you have permissions to the other
pcs, you won't be able to access them. But I don't think that is your
problem since you can't even see them.

It seems I made a bit of confusion between NetBEUI and NetBIOS. Now
I can see the other PC.
Many thanks indeed.