Computers can't ping each other

[rhymejerky]

I have 3 computers in a home network. 2 of them (Comp A and B) have wireless nics and 1 (Comp C) has a 10/100 based wired nic. All computer are connected to a D-link wireless router and can access the Internet w/o any problem. I have problem trying to create a share folder between Comp A and Comp C. When Comp A ping Comp C, I got 100% packet loss. Same thing for Comp C pinging Comp A. However, both computer can ping Comp B with no problem. Any pointers on what is going on? I googled in the past few hours, trying different solutions, but no avail (Tried changing the Node Type to Hybrid, checking to make sure the Computer Browser service is working... etc). Thanks!!

 

[outonalimb]

Do you have Windows Firewall enabled on the two problem computers? If it is, go to Control Panel and click Windows Firewall (this might be in Security Center depending on your view settings). Click the Exceptions tab and tick the File and Printer Sharing option. Click OK to confirm.

By default, Windows Firewall will not allow you to ping other computers on the LAN.

 

[linney]

How to troubleshoot TCP/IP connectivity with Windows XP

http://support.microsoft.com/default.aspx?scid=kb;en-us;314067&FR=1&PA=1&SD=HSCH

Sounds a bit like some setting in a firewall is disabling ICMP packets.

RTO when pinging a specific macine
thread779-951678

Cannot ping XP workstation
thread779-920007

 

[rhymejerky]

I have PC-cillan on both machines, but I exit out of it when I do the ping. Unless something is running in the background that I am not aware of. Quitting the appl should take care of the software firewall issues. I am using xp pro with sp1 only (installed sp2 before, but uninstalled it coz it caused appl failure), so xp firewall shouldn't be the culprit. I do have Aventail VPN client installed, but isn't activated unless I specifically logon to office. I have NetBIOS enabled over TCP/IP and have made a share of folders on both machines..

Linney, the links are great. Will try to focus more on the firewall issue

 

[linney]

Is "Safe Mode with Networking" a diagnostic option?

 

[outonalimb]

Is ICF (Internet Connection Firewall) turned on? This is the precursor to Windows Firewall found on SP2 machines. If it is then try turning it off.

Check out the following link also:

http://www.practicallynetworked.com/sharing/xp/ic_firewall.htm

 

[rhymejerky]

Both machines' windows ICF are unchecked. For a moment, I was able to ping my desktop from my laptop and saw my desktop in network places on my laptop, but not vice versa. After a reboot of both machines, they couldn't ping each other anymore.

linney: if i start my desktop in safe mode with networking, what steps to take for the diagnostic?

 

[linney]

I was just wondering if you could then just ping away without the baggage that loads in Normal Mode, thereby narrowing down the cause of the problem?

 

[rhymejerky]

linney and outonalimb, thank you so much for the info!! I finally got the 2 computers share. What I did was instead of just having tcp/ip in local area connection, I put in NWLink NetBios and NWLink IPX/SPx NetBIOS compatible transport Protocol. Also, I unchecked the Win ICF on my laptop and it just worked magically. I don't remmeber reading anything about require usage of the above 2 protocols for lan sharing. Anyhow, thank you much!!