XP network

[Pannonian]

I have a desktop, running XP Home, which is connected to the internet. I have a laptop, running XP Pro, which I want to connect to the internet via the desktop. I have a switch, and 2 ethernet cables. I have run the network setup wizard on both computers, and both are now members of the workgroup Mshome. However, they appear to be members of different workgroups called Mshome, for they can see themselves in the workgroup, but not each other. They can ping themselves, but not each other. Both computers are logged on under administrator accounts. The desktop is running Sygate personal firewall, which isn't noted for blocking network connections (unlike Norton). The laptop is running Windows firewall.

Any suggestions as to what might be going wrong?

[caravel]

Set up the desktop with a static IP address of 192.168.0.1 and subnet mask of 255.255.255.0 and set that up with a shared connection and windows firewall disabled.

The workgroup is irrelevant as it is only used for file and printer sharing. If you do want file and print sharing and it's not working then it is highly likely that your firewall is blocking it.

Set up the laptop with another static address of 192.168.0.2 and subnet 255.255.255.0 with windows firewall also disabled.

You will only need to run the personal firewall on the desktop and this box will act as the firewall and nat router for the laptop - which will now be the most secure of the two.

You may also need to enter the primary and secondary DNS servers in the network configuration of the laptop. In fact I recommend you do this anyway. You can find them by opening a terminal on the dekstop and doing "ipconfig /all" look for the primary and secondary DNS server entries near the bottom and copy these into your network config for the laptop. Another way to do this if you can't find these is to enter the address of the dekstop PC (192.168.0.1) into the primary DNS field only for the laptop. This will also work.

It's worth noting that you don't actually need the switch for connecting two NICs together, only a crossover cable is required.

[Mouzafphaerre]

.
An irrelevant question (having caught a nerd defenseless ):

I want to clear my DNS cache (ipconfig /flushdns) but it returns an error:

Windows IP Configuration

Could not flush the DNS Resolver Cache: Function failed during execution.

It can't flush it via the maintainance tab either. What are the possible reasons and solutions?

XP Pro, modem has router onboard, no windows firewall.


.

[caravel]

Check that the dns client service is running. From a terminal do "net start dnscache".

[Mouzafphaerre]

.

net start dnscache
The DNS Client service is starting.
The DNS Client service was started successfully.

ipconfig /flushdns

Windows IP Configuration

Successfully flushed the DNS Resolver Cache.

Thank you!

Flushing the DNS cache didn't help bypass the state censorship but I learned something new.
.

[caravel]

You now need to do "sc config dnscache start= auto"

(Note the space between the "=" and the "a")

Or you can leave it on manual and start it up when needed (to flush the cache) using "net start dnscache", then flush the dns resolver cache and stop the service again by doing "net stop dnscache" - to avoid having it running all the time. Personally I find the DNS Cache to be useful and have it set to automatic.

[R'as al Ghul]

The desktop is running Sygate personal firewall, which isn't noted for blocking network connections (unlike Norton). The laptop is running Windows firewall.

Any suggestions as to what might be going wrong?

Both Firewalls block the other computer. Try to disable the laptop firewall and you'll see the laptop from the desktop-PC.
You can configure the sygate firewall on your desktop-PC by using advanced rules. You can enter the IP or, better, the MAC address, to be allowed to connect.

[Pannonian]

Just to wrest things back to the original problem, I've set the IP addresses and subnet masks as per Caravel's suggestion, but left the preferred and alternate DNS servers empty as they were before, and now my laptop can see the desktop in the workgroup, but the desktop cannot see the laptop. Also, when I double click on the desktop, it tells me network path not found. The laptop can't access the internet, and it takes a while to update the window whenever I refresh the view of Mshome. Judging by the blinking on the switch, it's probably testing the connection. I've switched off Windows Firewall on the laptop, but kept the Sygate on the desktop.

BTW, I changed the IP on my network connection as per Caravel's suggestion, but left the internet IP the same as before, with a subnet mask of 255.0.0.0. Would changing it help?

Edit: I've jigged Advanced rules as per R'as al Ghul's suggestion to allow traffic to and from the laptop, and now it can access my desktop! My desktop still can't see the laptop though, and the laptop still can't access the internet.

Edit 2: Agh, too soon. The workgroup is inviible again on the laptop.

Edit 3: Why can't I shut up and just watch? Now both computers can see each other. Still no internet connection for the laptop though.

[caravel]

Edit 3: Why can't I shut up and just watch? Now both computers can see each other. Still no internet connection for the laptop though.

Manually enter the primary and secondary DNS servers in the network config for the laptop or enter the IP address of the desktop as the laptop's primary DNS server.

[Pannonian]

Manually enter the primary and secondary DNS servers in the network config for the laptop or enter the IP address of the desktop as the laptop's primary DNS server.

Still no joy re: laptop internet connection.

IP addres: 192.168.0.2
Subnet mask: 255.255.255.0
Default gateway:
Preferred DNS server:

For the latter two, I tried first one, then the other, with 192.168.0.1, which is the network IP of the desktop, and a.a.a.a, which is the internet IP of the desktop, and any combination thereof, but the laptop still can't connect to the internet, with the error "Cannot find server". The laptop can ping both 192.168.0.1 and a.a.a.a.

Sygate on the desktop allows all traffic using all protocols from 192.168.0.2, while the laptop's network connection isn't firewalled.

[caravel]

Still not properly configured.

The Default gateway and Preferred (Primary) DNS Server both should be the address of the desktop machine (192.168.0.1), do not use the public address. If this still doesn't work then manually enter the primary and secondary DNS server addresses in network config for the laptop.

This is my NIC config with the gateway and primary DNS the same.


-Edit: Test when you've done this and post the result of "ipconfig /all" from the laptop if it still fails to connect.

[Pannonian]

Laptop setup

Windows IP Configuration

Hostname: pannlap
Primary Dns Suffix:
Node type: Unknown
IP Routing Enabled: No
WINS Proxy Enabled: No

Ethernet adapter Local Area Connection

Connection-specific DNS Suffix:
Description: Ethernet
Physical Address: a.a.a.a.a.a
Dhcp Enabled: No
IP Address: 192.168.0.2
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.0.1
DNS Servers: 192.168.0.1

Edit: Having looked at this, I still can't see any problem with the client's setup, so here's the host's setup as well.

Windows IP Configuration

Hostname: panndesk
Primary Dns Suffix:
Node type: Hybrid
IP Routing Enabled: Yes
WINS Proxy Enabled: No

Ethernet adapter Local Area Connection

Connection-specific DNS Suffix:
Description: Ethernet
Physical Address: a.a.a.a.a.a
Dhcp Enabled: No
IP Address: 192.168.0.1
Subnet Mask: 255.255.255.0
Default Gateway:

Internet

Connection-specific DNS Suffix:
Description: WAN interface
Physical Address: a.a.a.a.a.a
Dhcp Enabled: No
IP Address: b.b.b.b
Subnet Mask: 255.255.255.255
Default Gateway: b.b.b.b
DNS Servers: c.c.c.c
d.d.d.d
NetBIOS over Tcpip: Disabled

[caravel]

And still not working? Have you tried manually inputting your DNS server addresses into the primary and secondary fields for the laptop?

[Pannonian]

And still not working? Have you tried manually inputting your DNS server addresses into the primary and secondary fields for the laptop?

No joy. From the laptop, I can ping 192.168.0.1 and b (which is the IP my desktop presents to the outside world), but neither c nor d. Strangely enough, the desktop can't ping c or d either, even though they're listed as its DNS servers, and even though the desktop has no problems connecting to the internet.

[Blodrast]

No joy. From the laptop, I can ping 192.168.0.1 and b (which is the IP my desktop presents to the outside world), but neither c nor d. Strangely enough, the desktop can't ping c or d either, even though they're listed as its DNS servers, and even though the desktop has no problems connecting to the internet.

Not necessarily strange - they may simply not accept ICMP packets, only DNS queries.

[Pannonian]

If this helps, I can repair the LAN connection on the laptop, but repairing the LAN connection on the desktop produces the following error.

The following steps of the repair operation failed:
Refreshing all DHCP leases and re-registering DNS names.

[caravel]

Hmmm... try manually entering the DNS servers on the desktop and then for the primary DNS of the laptop enter 192.168.0.1 and nothing for the secondary. Reboot, then try again.

[Pannonian]

Hmmm... try manually entering the DNS servers on the desktop and then for the primary DNS of the laptop enter 192.168.0.1 and nothing for the secondary. Reboot, then try again.

Desktop's internet connection was automatically obtaining an IP and DNS address. I left the IP automatic, but manually entered the 2 DNS addresses. I then entered the gateway and primary DNS for the laptop as 192.168.0.1. Tried IE on laptop, failed, rebooted laptop. Tried laptop IE again, failed, rebooted desktop. Tried laptop IE again, failed, rebooted laptop. Tried laptop IE again, failed. Throughout this, the filesharing has been working OK, and the desktop can connect to the internet.

So basically the laptop can't connect to a DNS, for whatever reason.

[caravel]

Desktop's internet connection was automatically obtaining an IP and DNS address. I left the IP automatic, but manually entered the 2 DNS addresses. I then entered the gateway and primary DNS for the laptop as 192.168.0.1. Tried IE on laptop, failed, rebooted laptop. Tried laptop IE again, failed, rebooted desktop. Tried laptop IE again, failed, rebooted laptop. Tried laptop IE again, failed. Throughout this, the filesharing has been working OK, and the desktop can connect to the internet.

So basically the laptop can't connect to a DNS, for whatever reason.

What is the desktop's internet connection? Is this a cable modem connection, a dsl/cable router or a DSL modem?

[Pannonian]

What is the desktop's internet connection? Is this a cable modem connection, a dsl/cable router or a DSL modem?

DSL modem.

[Xiahou]

Probably not what you want to hear, but I'd get a hardware router- you'll be much happier and more secure as well. You can get Linksys cable/dsl routers for less than $50....

[caravel]

DSL modem.

What type of DSL modem? USB? If so what make and model?

[Pannonian]

What type of DSL modem? USB? If so what make and model?

ADSL modem, sorry.

The SpeedTouch 330 is a bus powered USB ADSL modem suitable for connecting one PC or Apple Mac to a standard broadband line.

The latest driver version is v4.1 UK (April 2007). The driver is common to all hardware variants of the ST-330 and ST-USB: SpeedTouch USB, SpeedTouch 330 Bordeaux, SpeedTouch 330 Platinum and SpeedTouch 330 Blue.

This may be the problem, according to wiki.

Being a USB modem, and not an Ethernet modem, drivers and software must be installed in order for the Speedtouch USB to work. The absence of an Ethernet interface also means that a Local Area Network, or LAN, cannot be built using this modem, even with the use of a USB capable router or a USB Hub. Unless you use a computer with Windows Server and configure NAT (Network Address Translation) or load MS ISA server and use the modem as the external interface. You can also use other NAT/routing capable OS, like GNU/Linux or BSD.

It's not entirely 100% though, as technically speaking I'm not building a LAN using the modem, but accessing the outside world using it, while the LAN is taken care of by another NIC.

[caravel]

On the Desktop PC in network connections you should have two connections: "Local Area Connection" and something like "Speedtouch Connection" or something like "Connection <My ISP>". Leace the ISP connection alone and work on the local Area Connection only and set that ones IP to 192.168.0.1 and it's DNS servers to your DNS servers which you can discover by doing ipconfig /all.

You also need to share the speedtouch connection or other PCs won't be able to make use of it.

[R'as al Ghul]

Isn't it enough to enable "Internet Connection Sharing" for the network connection that your desktop PC uses to connect to the Internet?
Have you tried that?

[Pannonian]

Isn't it enough to enable "Internet Connection Sharing" for the network connection that your desktop PC uses to connect to the Internet?
Have you tried that?

The network setup wizard did that automatically at the start, and I've checked it since.

On the desktop's internet connection's Advanced tab, I have all 3 options checked under Internet Connection Sharing, plus the Internet Connection Firewall.

On the desktop's LAN connection's TCP/IP tab, I have:
IP address: 192.168.0.1
Subnet mask: 255.255.255.0
Default gateway:

Preferred DNS server: a.a.a.a
Alternate DNS server: b.b.b.b

Where a and b are the DNS addresses used by the internet connection. I've resetted first the laptop, then the desktop, but the same error persists when I try to look outside on the laptop: DNS not found. File sharing works, but the laptop can't access the outside world.

[Blodrast]

I don't know much Windows stuff, but I have a couple of ideas. Currently, it's not clear to me what exactly the problem is. Yes, you can't connect, but why exactly ? Where does the chain break ?
So far, the advice you were given covers everything I would have thought of (and then some), so I don't know what else to add. But maybe we can figure out what exactly the problem is.

So, one thing to try is to ping from the laptop some host in the outside world; do this _without_ resolving names (dunno if this is default on XP, it is on the 2k box I'm typing this atm; if not, it should have a switch to tell it not to resolve names). If the ping works, then we've narrowed down the problem to some DNS issue; if it doesn't, we can stop trying to fix the DNS, since it's a lower level problem.

Another thing we could try is, like I said earlier, to figure out where exactly it stops. I'll assume that the firewall rules for allowing the laptop outside are correct (on all existing firewalls). If your firewalls allow you to do logging, please enable it, and see if something gets recorded when you try to access the outside world from the laptop. Do this with all the firewalls involved (laptop, desktop, modem if applicable).

If your firewalls do not allow logging, or not to a sufficient extent, what we can try is to use something like Ethereal (ethereal.com). Don't panic at the idea of "network analyzer", it's extremely intuitive and easy to setup and use. And it's free and multi-platform. You can set this up first on the desktop, and sniff packets from the laptop - preferably on the WAN interface, to see if the packets even make it all the way there. Hopefully, they don't, so we know that the problem is somewhere before that point. In either case, this will narrow down the possibilities and help us localize the problem.

If anybody else has other ideas, please feel free to correct me or suggest better approaches.

[Caius]

Help guys, and sorry for such hijacking of thread.

In home, we have 2 pc's. We both need Internet connection, but we have just one modem. The thing is, we need to share Internet, but we cant. a WMI error is ******* our red and it won't allow me to share Internet. I need help on what to do.

[caravel]

Caius, I'd advise you to start your own thread or this one is going to get very confusing.



/On topic: Pannonian

I'm not entirely sure what it causing the problem with this network. I think you should try what Blodrast has suggested but it may help to try and break it down a little and it may not but here goes.

The desktop PC (and USB Speedtouch Modem) are functioning as the NAT router/gateway (the windows ICS/Firewall service is exactly this). That is that this PC should have one NIC installed configured as 192.168.0.1 with the subnet of 255.255.255.0. The next step is to go into network connections and share the connection so that other Users can access it. If you don't do this then it won't be available. This PC can then be connected directly to an ethernet hub or with a crossover cable directly to another PC (or in your cace a laptop).

The Laptop needs to be set up as the next address along (or any other address in the same range 192.168.0.x) from the Desktop. So this is 192.168.0.2 with the same subnet mask. For this Laptop's Primary DNS server enter the address of the Dekstop (192.168.0.1). The final step is to go to Internet Options in the control panel and click on the connections tab. Select Never dial a connection or if this is greyed out, disregard. Then click on the LAN Settings button and uncheck all boxes and close.

Go to the console and do "ping totalwar.org". The output should show replies as below, if it isn't then a firewall on the laptop may be blocking it. Go to network connections on the laptop again and ensure that the Windows Firewall is not enabled on the LAN connection. If there is any other Firewall software running on the laptop, disable it, and test again.

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\>ping totalwar.org

Pinging totalwar.org [0.0.0.0] with 32 bytes of data:

Reply from 208.111.158.12: bytes=32 time=135ms TTL=49
Reply from 208.111.158.12: bytes=32 time=134ms TTL=49
Reply from 208.111.158.12: bytes=32 time=134ms TTL=49
Reply from 208.111.158.12: bytes=32 time=135ms TTL=49

Ping statistics for 208.111.158.12:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 134ms, Maximum = 135ms, Average = 134ms

C:\>