Laptop having strange network problems (Windows XP)

[alcapella]

I have a small home network consisting of a desktop PC, a wireless router, and a laptop with wireless network card. Up until last week, it was all working fine, with the laptop being able to access shares on the PC, and having no problems accessing the Internet.

Now, the laptop cannot access the PC, although it still recognizes that it is there. As well, if I try to access the Internet using Firefox or Opera (preferred browsers), the browser times out and hangs around in a zombie state; if I try to access the Internet with Internet Explorer (least preferred option), there is no problem. I have been checking out various tips on debugging networking problems, and I have found that the laptop can ping the PC and the router by IP address, but times out when it tries to ping its own IP address. Also, if I try to access a DNS to resolve a name, it results in a zombie-state process.

I have eliminated hardware problems with the router - the PC can access the Internet and shares on the laptop with no problem through the router. I have eliminated a hardware problem with the wireless network card - IE can get out to the Internet, and I have also tried to connect the laptop to the router with a cable with the same results.

Any suggestions as to further diagnostics to try running, or on steps I could take to fix the problem?

Many thanks.

 

[toffeapple]

The fact that you are getting access to the internet with IE means you have no networking issues as far as routing goes...very strange that firefox is hanging have you checked proxy settings in firefox???....as far as the shares go i would create an account on each for the other giving full access and rejoin both pc's to a workgroup and make sure both pc's are in the same IP range with i presume they must be if they are both getting out on the net

 

[alcapella]

I don't use a proxy for Firefox, so I don't think that that is it... And it is happening with Opera, too...

At a very basic level, it seems to me as if it has something to do either with trying to access a DNS (any network diagnostics that I have run seem to all hang when they try to resolve a hostname), or the fact that the laptop can no longer ping itself. As I said, it can ping the router and the desktop computer with no packet loss whatsoever, and it can ping the loopback address (127.0.0.1), but it loses all the packets when it tries to ping itself.

 

[Mictlantecuhtli]

That sounds like a software firewall problem to me.

 

[alcapella]

That sounds like a software firewall problem to me.

Okay... We have Norton Internet Security installed, and I am pretty sure that no-one was fiddling with the firewall settings in it, but it *is* possible that it the settings got changed inadvertently. Any suggestions as to what to look for in the configuration for Norton's firewall?

Thanks.

 

[alcapella]

Okay... We have Norton Internet Security installed, and I am pretty sure that no-one was fiddling with the firewall settings in it, but it *is* possible that it the settings got changed inadvertently. Any suggestions as to what to look for in the configuration for Norton's firewall?

Thanks.

Well, it looks like the problem with accessing the Internet and pinging itself is indeed a configuration problem with Norton's firewall. If I turn the firewall off, I can ping quite readily, and Firefox doesn't hang. The network share problem is still there, but that's not as important. I'll get in touch with Symantec's support people to try to determine where the configuration file has gotten fouled up, but, in the meantime, if anyone has any suggestions as to what setting is the likely culprit...

Thanks.

 

[alcapella]

Problem with networking solved. Shares between the two computers still to go, but I'm working my way through some of the other threads here to resolve that one. This thread can be considered closed.

The configuration item in Norton Firewall that needed to be tweaked? Under "Networking", where you set Trusted and Restricted computers by IP address (individually or by network range), the laptop had the correct Network Address for the home network, but, for some reason, it didn't have the individual address of 127.0.0.1. So it would appear that the laptop trusted the other machines on the network, but it didn't trust itself. (I figured this out by comparing the firewall settings between the PC and the laptop.)

Thanks again.

 

[toffeapple]

bit of advice..get rid of nortons