Are you running any kind of software firewalls on the laptops?

Traceroute won't show anything but the other machine if the originator and
target are on the same subnet.

No. Iptables *is* installed, but ufw reports the status as inactive for
both laptops.

A little further digging and I found the problem, which had nothing to
do with either laptop. Wireless User Isolation was turned on in my
router. Turned this off and they can now see each other.

Glad to see you got it fixed. For future reference, what make and model is your
router?

It's a BT Voyager 2110.....................

Shows the setting works though, but at least you found it before
hitting your head against a brick wall trying to sort out a
non-existent problem with the PC's <lol>

DS> Wireless User Isolation was turned on in my router.

Good find. That is a keeper just in case I am faced with the problem someday.

Make sure the profile is set to public.

This may be a silly question but have you installed the software necessary
to transfer files? Unlike windows it is not installed automatically as part
of the operating system. You would need Samba server, unless you want to use
FTP or some variation of it.

I would say exactly the opposite - that linux, unlike windows, includes
all sorts of networking tools and protocols by default.

If what you are saying is true why do many people ( like myself) install
Samba? I did it so that my mixed network, which includes a couple of windows
machines, could all talk to each other. While my ultimate goal is to be 100%
linux it isn't possible because Trainz and2 other stops require windows.

You people are really setting me straight but where were you when I posted
questions about configuring Samba?

Samba helps in a mixed OS environment - if using a purely Linux
environment then it's not needed as far as I can make out but not had
the chance to test it. I know that first time a fresh install of
Ubuntu is pointed at a Windows share it will request Samba, plus all
the relevant dependencies that come with it.

LAC> If what you are saying is true why do many people ( like myself)
LAC> install Samba?

I know about Samba, I have used Samba, but I don't think I have loaded
it on Ubuntu. I can't find it in my Applications section, nor do I see any
preferences listed. I do connect my Ubuntu 10.04 to a Windows XP system
exporting both printers and a shared folder. I can use both the shared
printers
and the shared folder on the mixed systems I have.

Look in [ System / Administration ] to see if you have Samba
installed, chances are it's there. We have a mixed system here and
Samba was required when first linking to shared resources on a Windows
box on the network.

Windows network resource sharing is relatively easy by simply creating shares by
right clicking folders. The is done through the explorer interface and the
NetBIOS system that has been a part of Windows networking for years. Linux on
the other hand requires a bit more knowledge in how to export shares on the
server and mount these shares on the client side.

Although I will agree that Linux has a powerful set of tools, the features of
Linux (and Unix) are based on an entirely different achitecture.

Ah, so perhap the original poster meant that linux doesn't have native
microsoft windows networking software? Quite understandable since unix
has always had nfs, but samba is a relative newcomer. However, out of
the box, linux distros can do ssh, scp, sftp, ftp, rsync etc, so
networking is definitely a strong point.

And as for the foreign protocols, even samba is not that hard to set up
- if not included in the default install, it's just an apt-get away, and
a suitable management interface makes it fairly straightforward for the
novice.

I've set up unix servers with samba and webmin to allow completely
non-technical people to manage samba shares even back in the 1990s.

In Ubuntu, I right-click on a folder and select "sharing options," and specify
that it is to be shared, and a share name. It is exactly as complex as in
Windows. No unusual knowledge is needed, and there's no software to install or
configure. (The software is already installed and it requires no configuration.)

To use a shared folder, I open the Place "Network," and double-click my way to a
shared folder (workgroup, computer, share name). Just like Windows. No unusual
knowledge is needed, and no software needs to be installed or configured.

What do you mean "connect"? Access a shared folder? Remote desktop?

I routinely use shared folders in a wifi-based network. No firewalls, same
workgroup. Open the "place" Network, double-click on the workgroup, double-click
on the computer name. (They have different names?) Double-click on a share name.

Presumably both laptops can access the Internet.

You may be encountering a wifi security feature provided in many wireless
products that prevents wireless clients from accessing each other directly.
I'd suggest looking through your wireless setup to look for things like
"wireless privacy" or similar features. So long as these are enabled, they
will not be able to talk whilst associated to that router's wireless.

If I try a traceroute, it doesn't even get out of the host computer to the
> router.


If both are on the same subnet, the router will not be involved. You should
be able to traceroute to external addresses through the router however.


> They can both ping the devices that are cable connected to my router. Yes,
> I don't know what I'm doing ;-)
>

That's actually an excellent test. Are the laptops and wired computers all
in the same subnet (e.g. 192.168.0.x)? If so, this make me suspect that
wireless security features are blocking your attempts even more.


> Is it possible to achieve what I want to do, or is it not possible to
> connect two computers this way if they're on the same wifi hub?
>

It is certainly possible, but the specifics may depend on your wireless
equipment.

Keep in mind, until the two laptops can "see" each other on the network,
using ping, ssh or whatever other tests you like, there's no sense fighting
with samba, sharing or any other service that depends on the underlying
networking.