Networking problems with router between 2 p.c.'s

[David]

I think many people are having the same trouble I have
had trying to get 2 or more p.c.'s to network with WinXP
(either Home or Professional), and using a broadband
router for internet access. Please see my original post
on 18-Aug @ 11:10pm and the subsequent reply from Steve
Winograd. The trick seems to be that if you are using a
router for connection between the p.c.'s, (and a modem
behind that for internet connection), then you should
disable the internet connection firewall in the LAN
connections setup (in 'advanced' tab), on each machine.
So in this case the router will provide some firewall
protection and you will be able to network okay between
p.c.'s. If your p.c. connects directly to the internet
via the modem, then you must enable the firewall for that
connection only, to provide youself with some protection.
Bye. David.

 

[Jack]

Hi.

This inference is not accurate. You should disable the old WinXP Firewall
(ICF) and install a Good software Firewall.

Router's NAT Firewall is only Very partial protection from Internet "Junk".

Basic protection: http://www.ezlan.net/firewall.html

Internet Infestation: http://www.ezlan.net/infestation.html

Almost all Software firewall have a two set of settings, one for the
Internet and One for the LAN (many time refer to as Trusted Zone. you can
enter the IPs of your locale computers to the Trusted zone area and thus let
the computers internally converse with No Firewall interception.

The Internet part of the Firewall should stay On.

Jack (MVP-Networking).

 

[Steve Winograd [MVP]]

I agree, David. Running XP's Internet Connection Firewall does
nothing useful on a computer that connects to the Internet through a
broadband router. The router acts as a firewall, so ICF is at best
redundant. By design, ICS blocks file and printer sharing, so it
isn't suitable for use on a local area network.

It's different with the Windows Firewall in Service Pack 2, which can
allow file and printer sharing while closing other LAN ports that are
unnecessary and that can propagate network worms.

As Jack says, neither a router nor ICF can protect against unwanted
outgoing traffic from your computer due to spyware and Trojan horse
programs. However, by the time a malicious program starts sending
information out from your computer, the computer is badly compromised,
and simply running a firewall to block outgoing traffic isn't enough.
You need to be running a spyware removal program regularly. No
spyware = no undesired outgoing traffic.

I don't run outgoing firewalls on my computers, but I realize that
some people feel safer using them.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

 

[Trog Dog]

[snip]

redundant. By design, ICS blocks file and printer sharing, so it
isn't suitable for use on a local area network.

Would that explain the problem we have on our office LAN?

3 PC's with XP Pro SP2 connected thru a hub. 1 PC has dial-up modem and has
ICS enabled. All PC's are visible to each other. There are no problems
accessing the shared files on the two PC's that use the shared internet
connection. These files are visible and accessible from all 3 PC's.

The printers connected to the PC that hosts the internet connection are
visible and accessible from all 3 PC's.

However, the files shared on the internet host are not accessible from the
other two PC's.

It's not a major drama that this is occurring, but it would be nice to know
why it is happening.

Cheers

 

[Steve Winograd [MVP]]

I agree, David. Running XP's Internet Connection Firewall does
nothing useful on a computer that connects to the Internet through a
broadband router. The router acts as a firewall, so ICF is at best
redundant. By design, ICS blocks file and printer sharing, so it
isn't suitable for use on a local area network.

I'm sorry, but I made a typo above. ICS (Internet Connection Sharing)
doesn't block file and printer sharing. I should have said that ICF
(Internet Connection Firewall) blocks file and printer sharing. I
apologize for any confusion that I caused.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

 

[Steve Winograd [MVP]]

[snip]

redundant. By design, ICS blocks file and printer sharing, so it
isn't suitable for use on a local area network.

Would that explain the problem we have on our office LAN?

3 PC's with XP Pro SP2 connected thru a hub. 1 PC has dial-up modem and has
ICS enabled. All PC's are visible to each other. There are no problems
accessing the shared files on the two PC's that use the shared internet
connection. These files are visible and accessible from all 3 PC's.

The printers connected to the PC that hosts the internet connection are
visible and accessible from all 3 PC's.

However, the files shared on the internet host are not accessible from the
other two PC's.

It's not a major drama that this is occurring, but it would be nice to know
why it is happening.

Cheers

Since the host's printers are visible from all 3 PCs, a firewall isn't
blocking access to shared files.

If a shared file is visible (appears in My Network Places) but
inaccessible (an error occurs when you try to access it), the problem
can't be a firewall. A firewall would make it invisible.

BTW, I made a typo above. ICS (Internet Connection Sharing) doesn't
block file and printer sharing. I should have said that ICF (Internet
Connection Firewall) blocks file and printer sharing. I apologize for
any confusion that I caused.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

 

[Trog Dog]

[snip]

redundant. By design, ICS blocks file and printer sharing, so it
isn't suitable for use on a local area network.

Would that explain the problem we have on our office LAN?

3 PC's with XP Pro SP2 connected thru a hub. 1 PC has dial-up modem and
has
ICS enabled. All PC's are visible to each other. There are no problems
accessing the shared files on the two PC's that use the shared internet
connection. These files are visible and accessible from all 3 PC's.

The printers connected to the PC that hosts the internet connection are
visible and accessible from all 3 PC's.

However, the files shared on the internet host are not accessible from the
other two PC's.

It's not a major drama that this is occurring, but it would be nice to
know
why it is happening.

Cheers

Since the host's printers are visible from all 3 PCs, a firewall isn't
blocking access to shared files.

If a shared file is visible (appears in My Network Places) but
inaccessible (an error occurs when you try to access it), the problem
can't be a firewall. A firewall would make it invisible.

BTW, I made a typo above. ICS (Internet Connection Sharing) doesn't
block file and printer sharing. I should have said that ICF (Internet
Connection Firewall) blocks file and printer sharing. I apologize for
any confusion that I caused.

No files or shared directories are visible on the ICS computer, but that
computer is visible in network places on both client machines, however, when
you try to browse the host you get an access denied message. As I said ICS
works as does printer sharing, just not file sharing on the ICS host, even
though it has shared directories.

Just had a thought, I haven't checked to see if it's simple or classic
sharing that's enabled on the ICS host, although I suspect it would only be
simple file sharing, I'd better also check that the guest account is active
on the ICS host.

Anything else that I should check?