Is there a firewall?

  • Thread starter Thread starter Bob Campbell
  • Start date Start date
B

Bob Campbell

I have 4 XP Pro computers on a network, using a Linksys router, with DHCP.
Each can ping each other, except #2, #3 and #4 cannot ping computer 1.

I have ICF and ICS unchecked on all, but could there be another firewall? I
don't have Norton or ZA or anything. How can I find what's blocking the
pinging to computer 1? Maybe it's not even a firewall issue.

TIA. -Bob.
 
"Bob Campbell" said:
I have 4 XP Pro computers on a network, using a Linksys router, with DHCP.
Each can ping each other, except #2, #3 and #4 cannot ping computer 1.

I have ICF and ICS unchecked on all, but could there be another firewall? I
don't have Norton or ZA or anything. How can I find what's blocking the
pinging to computer 1? Maybe it's not even a firewall issue.

TIA. -Bob.
Click to expand...

It sure looks like there's a firewall blocking pings on #1.

You can enable or disable ICF individually on each network connection.
Make sure that it's disabled on the local area network connection.

Try temporarily disabling your antivirus program. Some of them can
interfere with the network.

If that doesn't help, start #1 in "Safe Mode with Networking", as
shown here:

A Description of the Safe Mode Boot Options in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;315222

Then, see if the other computers can ping it. If they can, some
program that normally runs on #1 is blocking pings. In that case, go
to Start | Run | Msconfig | Startup and see what's listed there.
--
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
 
Best Wishes
Thanks Steve for taking the time to respond.

On computer #1, I disabled all the items in msconfig startup, (and
rebooted), but that didn't help. I then booted up in Safe mode with
networking and that works: now I can ping #1. That's the good news. But now
I'm a bit stumped on figuring out what it is in particular that blocks the
pinging.

Bob.
 
Thanks Steve for taking the time to respond.

On computer #1, I disabled all the items in msconfig startup, (and
rebooted), but that didn't help. I then booted up in Safe mode with
networking and that works: now I can ping #1. That's the good news.
But now I'm a bit stumped on figuring out what it is in particular
that blocks the pinging.

Bob.
Click to expand...

I copied this from the msconfig help file, it may help you locate the
source of the problem:

To isolate problems using Selective Startup options
You must be logged on as a computer administrator in order to complete
this procedure.

On the General tab, click Selective Startup, and then clear all of the
subsequent check boxes. You will not be able to clear the Use Original
BOOT.INI check box.

Starting with the first available check box (Process SYSTEM.INI File),
select each check box one at a time, and restart the computer as prompted
until the problem is reproduced.

Once the problem reappears, click the tab that corresponds to the
selected file. For example, if the problem reappears after selecting the
Win.ini file, click the WIN.INI tab in System Configuration Utility.

Notes

You may want to print this Help topic before restarting your computer,
because you will not be able to open Help during startup.
Begin troubleshooting by selecting the first check box under Selective
Startup, and then restart the computer as prompted.
 
Azriel said:
I copied this from the msconfig help file, it may help you locate the
source of the problem:

To isolate problems using Selective Startup options
You must be logged on as a computer administrator in order to complete
this procedure.

On the General tab, click Selective Startup, and then clear all of the
subsequent check boxes. You will not be able to clear the Use Original
BOOT.INI check box.

Starting with the first available check box (Process SYSTEM.INI File),
select each check box one at a time, and restart the computer as prompted
until the problem is reproduced.

Once the problem reappears, click the tab that corresponds to the
selected file. For example, if the problem reappears after selecting the
Win.ini file, click the WIN.INI tab in System Configuration Utility.

Notes

You may want to print this Help topic before restarting your computer,
because you will not be able to open Help during startup.
Begin troubleshooting by selecting the first check box under Selective
Startup, and then restart the computer as prompted.
Click to expand...

That's pretty good advice, but I wouldn't un-check "Load System
Services", since many services are needed for Windows XP to run
properly.
--
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 and Azriel,

I found the problem. It was a service in the Msconfig Services: VPN Service
from Cisco Systems, Inc. which I've been using for several years, but
somehow is causing a problem now, perhaps because of a security patch in a
recent Windows Update. I'll probably report the issue/glitch to Cisco.

Thanks again guys for your help.

-Bob Campbell
 
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