Solved

Firewall blocking networked computers from accessing Internet

Posted on 2003-11-18
7
857 Views
Last Modified: 2010-03-19
Greetings

I have successfully networked 2 computers using a crossover cable:

Computer A: Win2k Pro, has internet connection shared using ICS, and ZoneAlarm firewall
Computer B: WinXP Pro

Computers A and B can communicate fine with each other - but when Computer A is running its firewall, computer B has no access to the internet at all.  This, despite the fact that I have explicitly set my local IP range (192.0.0.0-255) as a "trusted zone".  It also doesn't seem to matter which firewall I use; I've also tried McAfee's firewall product, and that also blocks any attempt by Computer B to access the Internet, even when I explicitly grant "Trusted" status to my local network.

But when the firewall is switched off, Computer B has perfect access to the Internet.

Any ideas how I might solve this?

Thanks,
Shaul

0
Comment
Question by:saulbehr
7 Comments
 
LVL 43

Expert Comment

by:JFrederick29
ID: 9778837
Are you able to create "Advanced or Expert Rules"?

Try creating a rule in your firewall software to allow your private IP range outbound access on port 80 (or all ports).
0
 
LVL 9

Expert Comment

by:drev001
ID: 9782563
Software firewalls in this kind of setup, IMO are a waste of time. Just buy a cheap router, then both machines are automatically protected by NAT against inbound attacks and you'll have a much more stable connection.
0
 
LVL 41

Expert Comment

by:stevenlewis
ID: 9783114
which firewall are you using?
I use Zone alarm, and have no problems with it
0
Better Security Awareness With Threat Intelligence

See how one of the leading financial services organizations uses Recorded Future as part of a holistic threat intelligence program to promote security awareness and proactively and efficiently identify threats.

 

Author Comment

by:saulbehr
ID: 9785190
I was using Zone Alarm, but I've now switched over to McAfee Personal Firewall.  It doesn't seem to make a difference.  I've explicitly put Computer B in my "Trusted Zone", both as an individual station with a specific IP address, as well as in the IP range of my local network, which should allow it full access through my firewall to the internet - but unfortunately this is all to no avail.  There doesn't appear to be any way of specifying exactly which port to grant access on, so I guess I've granted access on all ports.

Any other ideas?
0
 
LVL 43

Accepted Solution

by:
JFrederick29 earned 250 total points
ID: 9787055
From everything I have read online it appears that Zone Alarm and ICS don't work well together.  I would assume that ICS is probably the source of your problem.  Try using Sygate Personal Firewall (free) to see if it works better with ICS.

http://download.com.com/3000-2092-10049526.html?part=82835%20&subj=dlpage&tag=button
0
 

Author Comment

by:saulbehr
ID: 9788551
I think you might be right about Zone Alarm.  I've just tried again with McAfee, and it's working now.  (Wonder what happened first time??)
Can't vouch for Sygate, not having tried it myself, but for anyone else reading this PAQ, you might want to give it a try.
Thanks JFrederick29
0
 
LVL 43

Expert Comment

by:JFrederick29
ID: 9788621
You're welcome, glad to hear its working, thanks for the points.
0

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

A common practice in small networks is making file sharing easy which works extremely well when intra-network security is not an issue. In essence, everyone, that is "Everyone", is given access to all of the shared files - often the entire C: drive …
We recently endured a series of broadcast storms that caused our ISP to shut us down for brief periods of time. After going through a multitude of tests, we determined that the issue was related to Intel NIC drivers on some new HP desktop computers …
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

757 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

23 Experts available now in Live!

Get 1:1 Help Now