Problem with Network

[Neil Ginsberg]

I'm having major problems with my Windows XP (Home SP2). Everything was
trugging along fine. Then, all of a sudden, I can't connect my two computers
(both XP Home SP2, connected through a router, one wired, the other
wireless). The other computer shows up under Microsoft Windows Network. But
when I try to access it, I'm told that it's not accessible.

As noted, everything has been fine for years. Then, all of sudden this
happens.

Also, at the same time, some shortcuts aren't working. Like my shortcut to
Windows Media Player, which was configured by Windows to be:

"C:\Program Files\Windows Media Player\wmplayer.exe" /prefetch:1

won't work. When you click on it, it starts to go, then just stops. No
error. By taking out the "/prefetch:1" part, it works.

Another example: when I clicked on Network Setup Wizard from Network
Connections, same thing: it started to go, then just stopped after about a
second. But if I clicked on it from Windows Explorer | My Network Places, it
opened.

So things are pretty much screwed up.

At about the same time, I've been getting an onslaught of security messages
from Norton Firewall, telling me that a remote system is trying to access my
system. (That has been going on for about a week; the problem with the
network and the shortcut only about a day.)

Any ideas about what I can do to try and get my network working again?

Thanks!

Neil

 

[Neil Ginsberg]

Here's the latest on the situation below. I tried connecting the two PCs
directly with a network cable, rather than through the router. The message
"limited or no connectivity" came up. Going into the status area, it said:

"You might not be able to access the Internet or some network resources.
This problem occurred because the network did not assign a network address
to the computer."

I clicked the Repair button and got the message:

"Windows could not finish repairing the problem because the following action
cannot be completed: Renewing your IP address."

Any ideas?

Thanks,

Neil

 

[Chuck]

Here's the latest on the situation below. I tried connecting the two PCs
directly with a network cable, rather than through the router. The message
"limited or no connectivity" came up. Going into the status area, it said:

"You might not be able to access the Internet or some network resources.
This problem occurred because the network did not assign a network address
to the computer."

I clicked the Repair button and got the message:

"Windows could not finish repairing the problem because the following action
cannot be completed: Renewing your IP address."

Any ideas?

Thanks,

Neil

Neil,

The "limited or no connectivity" and subsequent "could not repair the
connection" are happening because your computer is not getting a DHCP address
assigned by the router.

Is this the wireless computer reporting this problem?
http://www.microsoft.com/technet/community/columns/cableguy/cg0804.mspx

Have you enabled the File and Printer Sharing exception in Windows Firewall on
both computers?

Please provide ipconfig information for each computer.
Start - Run - "cmd". Type "ipconfig /all >c:\ipconfig.txt" into the command
window - Open c:\ipconfig.txt in Notepad, copy and paste into your next post.
Identify operating system (by name and version) with each ipconfig listing.

Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.

 

[Neil Ginsberg]

See below.

Neil,

The "limited or no connectivity" and subsequent "could not repair the
connection" are happening because your computer is not getting a DHCP
address
assigned by the router.

Looking at the Wireless Connection Status for the wireless computer, I see
an IP of 192.169.2.2, with a subnet mask of 255.255.255.0, and a default
gateway of 192.168.2.1 -- which is what they've always been.

On the wired computer, I see 192.168.2.3, 255.255.255.0, and 192.168.2.1 --
which, again, is what they've always been on that computer.

So if Wireless Connection Status and Local Area Connection Status dialog
boxes are any indication, the PCs seem to be getting IPs.

Is this the wireless computer reporting this problem?
http://www.microsoft.com/technet/community/columns/cableguy/cg0804.mspx

Both computers are reporting the same problem. I upgraded to SP2 several
weeks ago and didn't have a problem. This started all of a sudden yesterday.

Note that the "limited or no connectivity" problem only happened when I
connected the two PCs directly, peer-to-peer. When I have them connected
through the router (as is the case with the IPs I noted above), I don't ge
that error, but the dialog box says, "Windows did not detect problems with
this connection."

Have you enabled the File and Printer Sharing exception in Windows
Firewall on
both computers?

I believe I disabled the Windows Firewall altogether (am using Norton
Firewall). So unless the SP2 upgrade turned it back on, it should be off
completely. However, I can't even get into the firewall to check. When I go
to Control Panel, I can't get into anything. Double-clicking on an item in
Control Panel causes the hourglass to come up for a split second; then it
disappears, and that's it. So I can't check it. That's on the wired
(desktop) computer.

On the wireless (laptop) computer, I am able to get into Control Panel
items, and, indeed, the Windows Firewall was on. I turned it off. But I
still can't get into the computer from the other one.

Please provide ipconfig information for each computer.
Start - Run - "cmd". Type "ipconfig /all >c:\ipconfig.txt" into the
command
window - Open c:\ipconfig.txt in Notepad, copy and paste into your next
post.
Identify operating system (by name and version) with each ipconfig
listing.

Both PCs are Win XP Home SP2. Below are for while connected through router
(usual configuration).

For desktop (wired):

Windows IP Configuration


Host Name . . . . . . . . . . . . : D23

Primary Dns Suffix . . . . . . . :

Node Type . . . . . . . . . . . . : Mixed

IP Routing Enabled. . . . . . . . : No

WINS Proxy Enabled. . . . . . . . : No



Ethernet adapter Local Area Connection:



Connection-specific DNS Suffix . :

Description . . . . . . . . . . . : Broadcom 440x 10/100 Integrated
Controller

Physical Address. . . . . . . . . : 00-08-74-BE-F6-5F

Dhcp Enabled. . . . . . . . . . . : Yes

Autoconfiguration Enabled . . . . : Yes

IP Address. . . . . . . . . . . . : 192.168.2.3

Subnet Mask . . . . . . . . . . . : 255.255.255.0

Default Gateway . . . . . . . . . : 192.168.2.1

DHCP Server . . . . . . . . . . . : 192.168.2.1

DNS Servers . . . . . . . . . . . : 192.168.2.1

Lease Obtained. . . . . . . . . . : Wednesday, September 22, 2004
3:15:52 PM

Lease Expires . . . . . . . . . . : Thursday, September 23, 2004
3:15:52 PM



PPP adapter Earthlink:



Connection-specific DNS Suffix . :

Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface

Physical Address. . . . . . . . . : 00-53-45-00-00-00

Dhcp Enabled. . . . . . . . . . . : No

IP Address. . . . . . . . . . . . : 4.131.92.136

Subnet Mask . . . . . . . . . . . : 255.255.255.255

Default Gateway . . . . . . . . . : 4.131.92.136

DNS Servers . . . . . . . . . . . : 207.69.188.187

207.69.188.186


For laptop (wireless):


Windows IP Configuration


Host Name . . . . . . . . . . . . : D51

Primary Dns Suffix . . . . . . . :

Node Type . . . . . . . . . . . . : Mixed

IP Routing Enabled. . . . . . . . : No

WINS Proxy Enabled. . . . . . . . : No



Ethernet adapter Local Area Connection:



Media State . . . . . . . . . . . : Media disconnected

Description . . . . . . . . . . . : Broadcom 440x 10/100 Integrated
Controller

Physical Address. . . . . . . . . : 00-0D-56-B5-C7-53



Ethernet adapter Wireless Network Connection:



Connection-specific DNS Suffix . :

Description . . . . . . . . . . . : Dell TrueMobile 1300 WLAN PC
Card

Physical Address. . . . . . . . . : 00-10-C6-32-2A-84

Dhcp Enabled. . . . . . . . . . . : Yes

Autoconfiguration Enabled . . . . : Yes

IP Address. . . . . . . . . . . . : 192.168.2.2

Subnet Mask . . . . . . . . . . . : 255.255.255.0

Default Gateway . . . . . . . . . : 192.168.2.1

DHCP Server . . . . . . . . . . . : 192.168.2.1

DNS Servers . . . . . . . . . . . : 192.168.2.1

Lease Obtained. . . . . . . . . . : Wednesday, September 22, 2004
3:31:57 PM

Lease Expires . . . . . . . . . . : Thursday, September 23, 2004
3:31:57 PM


Thanks,

Neil

 

[Chuck]

Looking at the Wireless Connection Status for the wireless computer, I see
an IP of 192.169.2.2, with a subnet mask of 255.255.255.0, and a default
gateway of 192.168.2.1 -- which is what they've always been.

On the wired computer, I see 192.168.2.3, 255.255.255.0, and 192.168.2.1 --
which, again, is what they've always been on that computer.

So if Wireless Connection Status and Local Area Connection Status dialog
boxes are any indication, the PCs seem to be getting IPs.


Both computers are reporting the same problem. I upgraded to SP2 several
weeks ago and didn't have a problem. This started all of a sudden yesterday.

Any idea what you were doing yesterday to trigger this?

Note that the "limited or no connectivity" problem only happened when I
connected the two PCs directly, peer-to-peer. When I have them connected
through the router (as is the case with the IPs I noted above), I don't ge
that error, but the dialog box says, "Windows did not detect problems with
this connection."

You have dialup (PPPoE?) on D23.

Are you using the router to share the dialup service? Or are you sharing the
service with ICS, and using the router to just connect the two computers? If
you're using ICS, have you disabled the router functionality?

To use a router as a hub, with an ICS server, you have to:
1) Disable DHCP on the router.
2) Connect the ICS server (D23), and all ICS clients (D51 etc), as peers to the
LAN side of the router.
3) Change the LAN address of the router from 192.168.0.1 to something like
192.168.0.99 (gotta keep it on 192.168.0/24 subnet).
4) Setup the LAN interface on the ICS server as 192.168.0.1.
5) Setup any ICS clients to use DHCP for all settings (obtain IP address and
DNS servers automatically).
6) If you're going to do file sharing, either disable ICF on the ICS LAN
connection (not recommended for a wireless router), or enable the FPS exception
in WF. Or disable WF, and configure NPF properly.

I believe I disabled the Windows Firewall altogether (am using Norton
Firewall). So unless the SP2 upgrade turned it back on, it should be off
completely. However, I can't even get into the firewall to check. When I go
to Control Panel, I can't get into anything. Double-clicking on an item in
Control Panel causes the hourglass to come up for a split second; then it
disappears, and that's it. So I can't check it. That's on the wired
(desktop) computer.

On the wireless (laptop) computer, I am able to get into Control Panel
items, and, indeed, the Windows Firewall was on. I turned it off. But I
still can't get into the computer from the other one.

Yuck. Norton Personal Firewall is know for NOT reacting well to being disabled.
The only solution here is to either un install NPF (using religiously all
instructions from Symantec), or enable it and configure it properly.

That is #1 on my list of causes of your problem.

<SNIP>

Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.

 

[Neil Ginsberg]

Both computers are reporting the same problem. I upgraded to SP2 several

Any idea what you were doing yesterday to trigger this?

No -- but the day before yesterday I was trying to fiddle with the IPs. D23
used to be 192.168.2.2 and D51 used to be 2.3. Then I moved a few days ago
and when I resetup my network, D51 got the 2.2 slot (since it connected
first, I guess). Since I had my PCAnywhere remotes set up with their old
IPs, I tried to get D23 to be 2.2 again -- mostly by clicking Repair and by
unplugging, rebooting, etc, with D51 turned off. But nothing worked. So I
accepted the new IPs and changed my PCA settings instead.

That was a couple of days ago, and everything was still working fine. Then,
yesterday, no more. So maybe the thing from two days ago had something to do
with it. I don't know.

You have dialup (PPPoE?) on D23.

Yes, that has to do with my move. I had DSL, with both computers accessing
it through the router. I'm currently using dial-up, but am still using the
router to connect the two PCs, with each PC dialing up directly (which,
BTW -- and thankfully -- neither one has problems with).

Are you using the router to share the dialup service? Or are you sharing
the
service with ICS, and using the router to just connect the two computers?
If
you're using ICS, have you disabled the router functionality?

Not sure what ICS is. But hopefully my response above answers that question.
If not, let me know.

To use a router as a hub, with an ICS server, you have to:
1) Disable DHCP on the router.
2) Connect the ICS server (D23), and all ICS clients (D51 etc), as peers
to the
LAN side of the router.
3) Change the LAN address of the router from 192.168.0.1 to something
like
192.168.0.99 (gotta keep it on 192.168.0/24 subnet).
4) Setup the LAN interface on the ICS server as 192.168.0.1.
5) Setup any ICS clients to use DHCP for all settings (obtain IP address
and
DNS servers automatically).
6) If you're going to do file sharing, either disable ICF on the ICS LAN
connection (not recommended for a wireless router), or enable the FPS
exception
in WF. Or disable WF, and configure NPF properly.


Yuck. Norton Personal Firewall is know for NOT reacting well to being
disabled.
The only solution here is to either un install NPF (using religiously all
instructions from Symantec), or enable it and configure it properly.

That is #1 on my list of causes of your problem.

A couple of thoughts on that.

First, in the past, whenever I've had network problems (a few, over the past
few years), it's either not been from NPF; or, if it was, it was cleared up
when NPF was disabled. Thus, I'm not very optimistic that NPF is the
problem.

Second, this thing about not being able to open anything from Control Panel
(and some shortcuts) is a serious thing. Something is screwed up there, and
my hunch is that whatever it is might be somehow related to the network
problem. Maybe not, but it seems very possible.

Thanks,

Neil

 

[Chuck]

First, in the past, whenever I've had network problems (a few, over the past
few years), it's either not been from NPF; or, if it was, it was cleared up
when NPF was disabled. Thus, I'm not very optimistic that NPF is the
problem.

Second, this thing about not being able to open anything from Control Panel
(and some shortcuts) is a serious thing. Something is screwed up there, and
my hunch is that whatever it is might be somehow related to the network
problem. Maybe not, but it seems very possible.

Neil,

I too am speaking from experience when I mention NPF and other third party
firewalls as being a possible problem. Keep an open mind please.

As to the latter concern, I know of two possible causes.
- Corrupted system program code.
- Trojan / virus intentionally interfering with system functions.

if you simply have corrupted code, "sfc /scannow" should check for that.

If you have a trojan or virus interfering with control panel functions, you need
to do a thorough security scan.

How current is your virus protection? Try one or more of these free online
virus scans, which should complement your current protection:
<http://www.bitdefender.com/scan/license.php>
<http://www.pandasoftware.com/activescan>
<http://www.ravantivirus.com/scan/>
<http://security.symantec.com/ssc/home.asp>
<http://housecall.trendmicro.com/housecall/start_corp.asp>

Now check for, and learn to defend against, additional problems - adware,
crapware, spyware.

Start by downloading each of the following additional free tools:
AdAware <http://www.lavasoftusa.com/>
CWShredder <http://www.majorgeeks.com/download4086.html>
CoolWWWSearch.SmartSearch (v1/v2) MiniRemoval
<http://www.majorgeeks.com/download4113.html>
HijackThis <http://www.majorgeeks.com/download.php?det=3155>
LSP-Fix and WinsockXPFix <http://www.cexx.org/lspfix.htm>
Spybot S&D <http://www.safer-networking.org/index.php?page=download>
Stinger <http://us.mcafee.com/virusInfo/default.asp?id=stinger>

Create a separate folder for HijackThis, such as C:\HijackThis - copy the
downloaded file there. AdAware and Spybot S&D have install routines - run them.
The other downloaded programs can be copied into, and run from, any convenient
folder.

First, run Stinger. Have it remove any problems found.

Next, close all Internet Explorer and Outlook windows, and run
CoolWWWSearch.SmartSearchMiniRemoval, then CWShredder. Have the latter fix all
problems found.

Next, run AdAware. First update it ("Check for updates now"), configure for
full scan (<http://www.lavahelp.com/howto/fullscan/>), then scan. When scanning
finishes, remove all Critical Objects found.

Next, run Spybot S&D. First update it ("Search for updates"), then run a scan
("Check for problems"). Trust Spybot, and delete everything ("Fix Problems")
that is displayed in Red.

Then, run HijackThis ("Scan"). Do NOT make any changes immediately. Save the
HJT Log.
<http://forums.spywareinfo.com/index.php?showtopic=227>

Finally, have your HJT log interpreted by experts at one or more of the
following security forums (and please post a link to your forum posts, here):
Aumha: <http://forum.aumha.org/index.php>
Net-Integration: <http://forums.net-integration.net/>
Spyware Info: <http://forums.spywareinfo.com/>
Spyware Warrior: <http://spywarewarrior.com/index.php>
Tom Coyote: <http://forums.tomcoyote.org/>

If removal of any spyware affects your ability to access the internet (some
spyware builds itself into the network software, and its removal may damage your
network), run LSP-Fix and / or WinsockXPFIx.

Finally, improve your chances for the future.

Harden your browser. There are various websites which will check for
vulnerabilities, here are three which I use.
http://www.jasons-toolbox.com/BrowserSecurity/
http://bcheck.scanit.be/bcheck/
https://testzone.secunia.com/browser_checker/

Block Internet Explorer ActiveX scripting from hostile websites (Restricted
Zone).
<https://netfiles.uiuc.edu/ehowes/www/main.htm> (IE-SpyAd)

Block known dangerous scripts from installing.
<http://www.javacoolsoftware.com/spywareblaster.html>

Block known spyware from installing.
<http://www.javacoolsoftware.com/spywareguard.html>

Make sure that the spyware detection / protection products that you use are
reliable:
http://www.spywarewarrior.com/rogue_anti-spyware.htm

Harden your operating system. Check at least monthly for security updates.
http://windowsupdate.microsoft.com/

Block possibly dangerous websites with a Hosts file. Three Hosts file sources I
use:
http://www.accs-net.com/hosts/get_hosts.html
http://www.mvps.org/winhelp2002/hosts.htm
(The third is included, and updated, with Spybot (see above)).

Maintain your Hosts file (merge / eliminate duplicate entries) with:
eDexter <http://www.accs-net.com/hosts/get_hosts.html>
Hostess <http://accs-net.com/hostess/>

Secure your operating system, and applications. Don't use, or leave activated,
any accounts with names or passwords with trivial (guessable) values. Don't use
an account with administrative authority, except when you're intentionally doing
administrative tasks.

Use common sense. Yours. Don't install software based upon advice from unknown
sources. Don't install free software, without researching it carefully. Don't
open email unless you know who it's from, and how and why it was sent.

Educate yourself. Know what the risks are. Stay informed. Read Usenet, and
various web pages that discuss security problems. Check the logs from the other
layers regularly, look for things that don't belong, and take action when
necessary.

Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.