MS Internet Connection Firewall on LAN

[Sigurd Kallhovde]

As far as I have been able to ascertain, when I turn the Microsoft Internet
Connection Firewall on, it has the undesirable effect of also shutting down
PC-to-PC communication on my LAN (behind a Linksys BEFSR41 router).

Is there a way to keep the LAN open with ICF turned on?

Thank you.

Regards,
Sigurd

 

[BobC]

As far as I have been able to ascertain, when I turn the Microsoft Internet
Connection Firewall on, it has the undesirable effect of also shutting down
PC-to-PC communication on my LAN (behind a Linksys BEFSR41 router).

Is there a way to keep the LAN open with ICF turned on?

Thank you.

Regards,
Sigurd

If you consult the windows help on your computer it clearly states that ICF
is for use only on computers directly connected to the Internet and may
interfere with LAN communications if turned on for LAN connections.

If you want a firewall on your LAN try one of the good free firewalls such
as zonealarm or sygate.

 

[Steve Winograd [MVP]]

As far as I have been able to ascertain, when I turn the Microsoft Internet
Connection Firewall on, it has the undesirable effect of also shutting down
PC-to-PC communication on my LAN (behind a Linksys BEFSR41 router).

Is there a way to keep the LAN open with ICF turned on?

Thank you.

Regards,
Sigurd

Yes. Open the following ports in the firewall: TCP 139, TCP 445, UDP
137, UDP 138.
--
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

 

[Sooner Al]

In addition to Steve's comments, the new Windows Firewall that is included in the upcoming release
of SP2 will have a simple checkbox to enable File & Print Sharing. It works quite well. Here is a
preview...

http://www.microsoft.com/technet/community/columns/cableguy/cg0204.mspx

--
Al Jarvi (MS-MVP Windows Networking)

Please post *ALL* questions and replies to the news group for the mutual benefit of all of us...
The MS-MVP Program - http://mvp.support.microsoft.com
This posting is provided "AS IS" with no warranties, and confers no rights...

 

[Doug Sherman [MVP]]

This is by design. See:

http://support.microsoft.com/default.aspx?scid=kb;en-us;298804

You can open NetBIOS ports, but that is sort of self defeating. If you wish
to run firewalls on network machines behind your router's firewall, use a
third party product which allows you to restrict access by IP address or
user credentials. Also, some double firewall configurations may not allow
Internet access through a NAT router.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP