Peer to Peer problem

Two computers, an HP desktop & a Toshiba laptop, share this problem. They can
get to the Internet wireless through a Checkpoint firewall appliance/ap and
email is no problem. They cannot see each other for peer to peer file
sharing. Turned off XP's firewall and disabled F-Secure all together but to
difference. As an experiment I connected them with a crossover cable and
assigned IP's but still can ping each other. If I connect my laptop, either
one of them can ping me but I cannot ping either of them. I can find no other
software installed that might explain this. The F-Secure is current and up to
date and runs a daily scan so virus or trojans are unlikely. The HP desktop
has Internet Connection sharing turned on even though the Internet is through
the CheckPoint appliance.
Any ideas anyone?
John.

John
Sat Jun 07 17:28:25 PDT 2008

=?Utf-8?B?Sk9ITkZEUw==?= <JOHNFDS@discussions.microsoft.com> wrote
in news:3BCFDDCB-3943-4298-979D-B755DB6C2579@microsoft.com:

> Two computers, an HP desktop & a Toshiba laptop, share this
> problem. They can get to the Internet wireless through a
> Checkpoint firewall appliance/ap and email is no problem. They
> cannot see each other for peer to peer file sharing. Turned off
> XP's firewall and disabled F-Secure all together but to
> difference. As an experiment I connected them with a crossover
> cable and assigned IP's but still can ping each other. If I
> connect my laptop, either one of them can ping me but I cannot
> ping either of them. I can find no other software installed that
> might explain this. The F-Secure is current and up to date and
> runs a daily scan so virus or trojans are unlikely. The HP desktop
> has Internet Connection sharing turned on even though the Internet
> is through the CheckPoint appliance.
> Any ideas anyone?
>

This certainly sounds like a firewall problem.

By chance, do you have the Cisco Systems VPN Client installed?
If so, start up the client and make sure there is no checkmark beside
"Stateful Firewall (always on)" under the "Options" menu. This will
haunt you even if you don't have the VPN client currently running.

Also note that if you have a VPN active, sometimes the local network
is logically disconnected for security reasons.

Shot-in-the-dark,
John

JOHNFDS
Sun Jun 08 07:41:01 PDT 2008

Did not see Cisco software installed either in "Add/Remove Programs" or in
Start / Programs. Have not checked the directories under Programs Files yet.
The VPN appears to be a site to site VPN from the Checkpoint appliance to
the other side.

John.

"John Wunderlich" wrote:

> =?Utf-8?B?Sk9ITkZEUw==?= <JOHNFDS@discussions.microsoft.com> wrote
> in news:3BCFDDCB-3943-4298-979D-B755DB6C2579@microsoft.com:
>
> > Two computers, an HP desktop & a Toshiba laptop, share this
> > problem. They can get to the Internet wireless through a
> > Checkpoint firewall appliance/ap and email is no problem. They
> > cannot see each other for peer to peer file sharing. Turned off
> > XP's firewall and disabled F-Secure all together but to
> > difference. As an experiment I connected them with a crossover
> > cable and assigned IP's but still can ping each other. If I
> > connect my laptop, either one of them can ping me but I cannot
> > ping either of them. I can find no other software installed that
> > might explain this. The F-Secure is current and up to date and
> > runs a daily scan so virus or trojans are unlikely. The HP desktop
> > has Internet Connection sharing turned on even though the Internet
> > is through the CheckPoint appliance.
> > Any ideas anyone?
> >
>
> This certainly sounds like a firewall problem.
>
> By chance, do you have the Cisco Systems VPN Client installed?
> If so, start up the client and make sure there is no checkmark beside
> "Stateful Firewall (always on)" under the "Options" menu. This will
> haunt you even if you don't have the VPN client currently running.
>
> Also note that if you have a VPN active, sometimes the local network
> is logically disconnected for security reasons.
>
> Shot-in-the-dark,
> John
>
>

JOHNFDS
Mon Jun 09 16:35:01 PDT 2008

No Cisco VPN but there appears to be WinVNC installed. Am unable to launch
WinVNC though attempting to results in various error messages. No sign of it
in the Tsk Manager.

They appear to have a site to site VPN in place. I do not see any
Checkpoint software on the PCs. I could see the Checkpoint box blocking
inbound on the wireless NIC but blocking the wired NIC?

John

"John Wunderlich" wrote:

> =?Utf-8?B?Sk9ITkZEUw==?= <JOHNFDS@discussions.microsoft.com> wrote
> in news:3BCFDDCB-3943-4298-979D-B755DB6C2579@microsoft.com:
>
> > Two computers, an HP desktop & a Toshiba laptop, share this
> > problem. They can get to the Internet wireless through a
> > Checkpoint firewall appliance/ap and email is no problem. They
> > cannot see each other for peer to peer file sharing. Turned off
> > XP's firewall and disabled F-Secure all together but to
> > difference. As an experiment I connected them with a crossover
> > cable and assigned IP's but still can ping each other. If I
> > connect my laptop, either one of them can ping me but I cannot
> > ping either of them. I can find no other software installed that
> > might explain this. The F-Secure is current and up to date and
> > runs a daily scan so virus or trojans are unlikely. The HP desktop
> > has Internet Connection sharing turned on even though the Internet
> > is through the CheckPoint appliance.
> > Any ideas anyone?
> >
>
> This certainly sounds like a firewall problem.
>
> By chance, do you have the Cisco Systems VPN Client installed?
> If so, start up the client and make sure there is no checkmark beside
> "Stateful Firewall (always on)" under the "Options" menu. This will
> haunt you even if you don't have the VPN client currently running.
>
> Also note that if you have a VPN active, sometimes the local network
> is logically disconnected for security reasons.
>
> Shot-in-the-dark,
> John
>
>

John
Tue Jun 10 12:37:35 PDT 2008

=?Utf-8?B?Sk9ITkZEUw==?= <JOHNFDS@discussions.microsoft.com> wrote
in news:E656EE4D-85B0-4F24-BC31-7DE60B5D84F6@microsoft.com:

> No Cisco VPN but there appears to be WinVNC installed. Am unable
> to launch WinVNC though attempting to results in various error
> messages. No sign of it in the Tsk Manager.
>
> They appear to have a site to site VPN in place. I do not see any
> Checkpoint software on the PCs. I could see the Checkpoint box
> blocking inbound on the wireless NIC but blocking the wired NIC?
>

I have no idea what the problem might be.

On the off-chance it might help, you might try running one of the
following tools. Sometimes it helps:

LSPFix: <http://cexx.org/lspfix.htm>
Winsock XP Fix: <http://www.download3k.com/Install-WinSock-XP-Fix.html>

HTH,
John