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Computers refuse to access the Internet

Pookhal
Advisor

Computers refuse to access the Internet

I have a peer-to-peer workgroup environment set up at home with Windows 2000 Advanced Server on my desktop computer directly connected to my Windows XP HP laptop.

The cable modem is directly connected to the my laptop via a USB Ethernet adapter. So at the moment, the laptop is playing host.

When I check connectivity through the ping command, the desktop computer can get responses from the NIC from the laptop and the USB Ethernet adapter all fine and dandy.

HOWEVER, when the desktop tries to ping the default gateway of the USB adapter or any domain name on the Internet, the requests always timeout. =|

I've tried making the Win2K computer as the host but the same thing happens.

It seems like whichever computer is being the host kills any packets the client computer tries to send to the Internet.

Other info:
- Internet sharing IS on on the laptop/host.
- the workgroup names are correct
- I've configured static IPs for the desktop and laptop with NetBIOS enabled.
- The USB adapter connected to the is set to automatically obtain IP and DNS with the default NetBIOS setting.

I know it really shouldn't be this difficult to get the Internet to work on both machines but it seems like ever since I reinstalled Windows XP on the laptop, trying to get Internet Sharing to work has become a big pain.
5 REPLIES
Pookhal
Advisor

Re: Computers refuse to access the Internet

Oops. I neglected to mention that the cable connection always works fine with the host computer.
Fernando Santos_1
Occasional Advisor

Re: Computers refuse to access the Internet

Hi! If you are using ISC on the host you should use dynamic IP on the laptop. This is because ICS implement a small built-in dhcp server.

For more help look out this ms article: http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/WINDOWS2000/en/server/help/HowTo_share_conn.htm

best regards
Any tip can help. Helping or not!
Ron Kinner
Honored Contributor

Re: Computers refuse to access the Internet

Only registered IP addresses are allowed on the Internet. Your peer to peer network uses unregistered addresses - hopefully those in the public ranges: 10.0.0.0 -10.255.255.255, 172.16.0.0-172.31.255.255.255, 192.168.0.0-192.168.255.255.

Your host PC has to perform Network Address Translation (NAT) on the public addresses in order to get them to work on the Internet. NAT replaces the invalid source address with a valid registered IP address - in your case that assigned by your cable modem (which may be doing NAT too so you might not really have a valid address but double NAT is also possible tho not very nice). It is possible that NAT is working. XP being fairly simple minded probably assumes that the addresses given out by its own DHCP server are the only ones which need NAT. If you have assigned your own static IP's and they are not in the DHCP server's range then they are probably being sent out without NAT. I believe MS is fond of using 192.168.0.1 as the address of the host that has the internet connection. You should have an address on 192.168.0.2 mask 255.255.255.0 default gateway of 192.168.0.1 on your client or let it pick up the ip address with DHCP. Make sure that you do not have another default gateway address assigned on your client.

On the host the default gateway should point to the cable modem. Do not fill in a gateway on the NIC which goes to the client.

Since XP is NT based I assume you can check your connections with the command ipconfig /all
.

http://www.practicallynetworked.com/sharing/xp_ics/

One final possible problem. Since you are using static addresses you may not have the correct DNS servers set. You can copy the ones being used by the host and use them on the client.

Ron
Pookhal
Advisor

Re: Computers refuse to access the Internet

Actually, this is a little embarassing to say but it turns out the firewall program, Zone Alarm, was responsible for the problem.

I exited the program and the desktop computer was able to access the Internet.

The thing is, I WANT to keep Zone Alarm up on the laptop (as it's directly connected to the cable modem), but I can't figure out how to allow the Windows 2K machine out onto the Internet while it's up. =/
Ron Kinner
Honored Contributor

Re: Computers refuse to access the Internet

Zone Alarm: Security: Advanced

Make sure your have your local network checked. You may need to add the other computer to the list.

Then on Zone Alarm: Security:

If it still doesn't work then try moving the left slider down to low.

Ron