At home I have a laptop (Win 7 Pro 64-bit) a desktop (Win XP Pro 32-bit). Up until a few days ago my home network was running fine--I could see each computer and the shared directories over the network. The computers were both members of a workgroup, WORKGROUP1 (not a homegroup). Then I took my laptop to another house, and changed my workgroup to theirs, WORKGROUP2. It worked fine and I could see their computers and shared files. When I got back home though, and back on WORKGROUP1, my home network did not work. When viewing the network from either computer, I can only see the local machine. When I try to ping one machine from the other using the DNS name, I get: Ping request could not find the host COMPUTER2. Please check the name and try again. When I try to ping one machine from the other using IP address, I get: Reply from 192.168.1.4: Destination host unreachable. --Both machines can ping the router (192.168.1.1), and can see the outside world (internet works fine). --Both computers are members of WORKGROUP1 --File and Printer sharing is turned on for both. --Network type of the Win 7 machine is "Home." But the same problems persist if I switch to "Work" or "Public." Any other thoughts, or diagnostics I can try? I'm out of ideas. I've obviously rebooted numerous times.

On Windows 7, the error "Destination host unreachable" is a bit misleading because in pre Vista systems, this error message meant that the computer did not have the appropriate information in the local routing table to get to the destination host. In Win 7, its the equivalent to Request Timed Out. The first think I would verify is if your issue is firewall related. Check both systems and make sure that ICMP is not being blocked. Since you mentioned that both can PING the router, the IP config on both machines is likely to be correct. However, just give it a second look at well. Make sure the subnet mask is correct on both computers. Visit: anITKB.com, an IT Knowledge Base.

If both machines can access Internet resources fine, but can't ping each other, it would indicate to me that their NICs are properly configured and working as expected. I assume this is a SOHO network so both computers are on the same subnet. Therefore, I still beleive that there must be some firewall software or filtering happening on either or both computers preventing ICMP from passing back and forth. Some AV client software packages also come with a firewall component as well. You may want to verify that. Visit: anITKB.com, an IT Knowledge Base.

Thanks for the reply. I forgot to mention that I disabled Windows Firewall on each machine, and removed all password requirements for logon. When I did so, and tried pinging one machine from the other, I got: Pinging COMPUTER1 (192.168.1.4) with 32 bytes of data: Request timed out Request timed out Request timed out Request timed out So the ping knew that COMPUTER1 had that IP address. However it did not reach it. The subnet masks are also the same for each. Any thoughts in light of this?

I'm using the free version of AVG on each machine, which does not have a firewall. And again, everything was working fine up until a few days ago when I took my laptop to a friend's house and got on their workgroup. I'm now back on my workgroup and can't see any computers on my home network. Curiously, when I take my laptop back to my friend's house, I can still see their network computers. Are there any other diagnostics, like pinging, that I can check? If not, is there a way to start over from scratch without re-installing Windows? I've tried taking each machine off the network, but that hasn't worked.

When dealing with ICMP results, there is no dependence on workgroup or domain membership. Try this.. Can the Win 7 computer ping the XP by its IP address? Can the XP computer ping the Win 7 by IP address? If you would like, please post the results of IPCONFIG /all from the Win 7 and Win XP to verify your settings.Visit: anITKB.com, an IT Knowledge Base.

I cannot succesfully ping either machine from the other. Here are ping results (by both name and IP address) from both Win 7 machine (desolace, 192.168.1.4) and the XP machine (westfall, 192.168.1.7). Of note is the "Connection-specific DNS Suffix . : home" line, which appends a 'home' to the end of each name when searching. Should this be? The name of my workgroup is 'azeroth.' Microsoft Windows [Version 6.1.7600] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Users\Snarl>ping westfall Pinging westfall.home [192.168.1.7] with 32 bytes of data: Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Ping statistics for 192.168.1.7: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), C:\Users\Snarl>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : desolace Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Broadcast IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : home Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : home Description . . . . . . . . . . . : Intel(R) Wireless WiFi Link 4965AGN Physical Address. . . . . . . . . : 00-1D-E0-89-3E-BF DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::21d:e0ff:fe89:3ebf%12(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.1.4(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Saturday, April 16, 2011 3:48:15 AM Lease Expires . . . . . . . . . . : Sunday, April 17, 2011 8:34:03 AM Default Gateway . . . . . . . . . : 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DHCPv6 IAID . . . . . . . . . . . : 352329184 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-AA-1C-58-00-1C-23-0E-56-34 DNS Servers . . . . . . . . . . . : 192.168.1.1 71.252.0.12 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.home: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : home Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Local Area Connection* 9: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:3c85:1ce2:52b6:54b4(Pref erred) Link-local IPv6 Address . . . . . : fe80::3c85:1ce2:52b6:54b4%15(Preferred) Default Gateway . . . . . . . . . : :: NetBIOS over Tcpip. . . . . . . . : Disabled C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl> C:\Users\Snarl>ping westfall Pinging westfall.home [192.168.1.7] with 32 bytes of data: Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Ping statistics for 192.168.1.7: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), C:\Users\Snarl>ping 192.168.1.7 Pinging 192.168.1.7 with 32 bytes of data: Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Reply from 192.168.1.4: Destination host unreachable. Ping statistics for 192.168.1.7: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), C:\Users\Snarl>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : desolace Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Broadcast IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : home Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : home Description . . . . . . . . . . . : Intel(R) Wireless WiFi Link 4965AGN Physical Address. . . . . . . . . : 00-1D-E0-89-3E-BF DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::21d:e0ff:fe89:3ebf%12(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.1.4(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Saturday, April 16, 2011 3:48:15 AM Lease Expires . . . . . . . . . . : Sunday, April 17, 2011 8:34:02 AM Default Gateway . . . . . . . . . : 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DHCPv6 IAID . . . . . . . . . . . : 352329184 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-AA-1C-58-00-1C-23-0E-56-34 DNS Servers . . . . . . . . . . . : 192.168.1.1 71.252.0.12 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.home: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : home Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Local Area Connection* 9: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:3c85:1ce2:52b6:54b4(Pref erred) Link-local IPv6 Address . . . . . : fe80::3c85:1ce2:52b6:54b4%15(Preferred) Default Gateway . . . . . . . . . : :: NetBIOS over Tcpip. . . . . . . . : Disabled C:\Users\Snarl> C:\Documents and Settings\Snarl>ping desolace Pinging desolace.home [192.168.1.4] with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for 192.168.1.4: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), C:\Documents and Settings\Snarl>ping 192.168.1.4 Pinging 192.168.1.4 with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for 192.168.1.4: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), C:\Documents and Settings\Snarl>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : westfall Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : home Ethernet adapter Wireless Network Connection 2: Connection-specific DNS Suffix . : home Description . . . . . . . . . . . : Microsoft Wireless Notebook Adapter MN-730 Physical Address. . . . . . . . . : 00-0D-3A-24-41-0C Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.1.7 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DNS Servers . . . . . . . . . . . : 192.168.1.1 71.252.0.12 Lease Obtained. . . . . . . . . . : Saturday, April 16, 2011 11:08:36 AM Lease Expires . . . . . . . . . . : Sunday, April 17, 2011 11:08:36 AM C:\Documents and Settings\Snarl>

Thanks for the time you've put into this. Windows Firewall is definitely disabled on each machine, and the only anti virus is AVG free edition, which has no firewall. The wireless router itself has a firewall. But this was all working perfectly fine until a week ago, and no changes were made. I tried plugging my XP machine directly into the router via ethernet cable. When I did so I got interesting results. Now I can succesfully ping each machine from the other, both by name and IP address. However when I view the network via explorer, I can only see the local machine. Again, both are part of the same workgroup. Thoughts? Edit: Upon reboot of both machines, the XP machine can ping the Win7 machine by both name and IP address. The Win7 machine can ping the XP machine only by IP address. It cannot find the host when I try to ping by name. Earlier, when I plugged the XP machine directly into the router, its IP address changed. Now, on the Win7 machine, when I do an nslookup on the XP machine name, it returns the *old* IP address it had for the XP machine. So I gather that, when I ping the XP machine by name, the Win7 machine still thinks it matches the old IP address. How can I remedy this?

Ok, so from an IP perspective, both of your computers are configured correctly. They both are configured as dhcp clients obtaining their configuration from the default gateway, which I am going to assume is your router. Since these computers can communicate without any issues with internet nodes, there is nothing preventing these two computers from communicating with each other, at least from a layer 2 networking perspective. they are both in the same subnet, same subnet mask. Based on what you have described, I still feel that the most likely culprit here is some type of filtering application on either or both computers. I would say that either the Windows firewall is enabeled, or you have 3rd party software running on either or both computers.Visit: anITKB.com, an IT Knowledge Base.

Ok, I had assumed that these systems were plugged into your router. Should have asked... To view the computers on the network via network explorer in your scenario, you'll need to enable the Computer Browser service on both systems. Its most likely set to Automated on your XP computer, but not likely on your Win 7 system. You can access the services via the Admin tools, or simply create an MMC console. Name Resolution; Since you are depending on your router for name resolution, you can log into the router and make sure that there arent any old information for the clients it has learned about (some routers have features such as this for local name resolution). Of course to clear the client's DNS cache, open a command prompt and type ipconfig /flushdns Visit: anITKB.com, an IT Knowledge Base.

Man the plot keeps getting thicker. 1. I verified that the Computer Browser service was running on both machines. 2. I tried to log into my router, but realized I don't know the login credentials. I am currently hunting them up. 3. I cleared the DNS cache on the XP machine, but still had the same problem. Actually here's the error I get when I try to ping the XP machine (192.168.1.6) from the Win 7 machine: > ping westfall. Server: westfall Address: 192.168.1.7 DNS request timed out. timeout was 2 seconds. DNS request timed out. timeout was 2 seconds. *** Request to westfall. timed-out More troublesome, 'ipconfig' used to work fine until *today.* But here's what happens when I try an ipconfig from the Win 7 machine: > ipconfig Server: Wireless_Broadband_Router.home Address: 192.168.1.1 ***Wireless_Broadband_Router.home can't find ipconfig: Non-existent domain AND, periodically I get an error message on the XP machine saying there's an IP address conflict with another computer on the network. I'd like to resolve this issue, but the "non-existent domain" problem is not allowing that, b/c it is preventing me from running things like 'ipconfig' and 'netstat.' What's going on here?

Embarassing. OK that's resolved. One curiousity is that when I run a netstat on the XP machine, it of course lists all the connections to the local machine. For each of those it lables the local address with the computer name, ie "westfall:XXXX." But when I run a netstat on the Win 7 machine: 1. It lables the local address with the IP address, ie "192.168.1.4.XXXX." 2. There are 5 connections that are to a different local address, "127.0.0.1.XXXX" Are these discrepancies anything to be concerned about? Regardeless, the main problem is that the Win 7 machine still thinks 'westfall' has a certain IP address, while it in fact has changed. How do I update the DNS records that the Win 7 machine checks when trying to ping a computer name?

the IPCONFIG error you got is easy to resolve. the problem is that you typed in "IPCONFIG" while still within the NSLOOKUP prompt. When you are done with NSLOOKUP, you need to type the word "exit" then hit enter. You'll be taken back to the command prompt. Visit: anITKB.com, an IT Knowledge Base.

I wouldnt be to concerned about the netstat with regard to troubleshooting this. Updating DNS depends on where DNS is. In your scenario, DNS is running on the router. So it depends on how that model of router handles DNS services. Normally, if you were running a standard implemnetation of DNS on a server, you would just open the DNS console and edit the static records. Have you checked that you do not have a static entry in your local HOSTS file. To check go to %systemroot%\system32\drivers\etc. open the file with notepad. make sure you do not have a static entry for that host. Regardless of the name resolution issue that you are trying to resolve, you would still be able to PING by IP without DNS. So until you resolve the ICMP issue, the rest of it is not important at this moment. Have you tried to introduce another computer on the network to see if you can replicate this issue on a totally different machine? If you are sure that there are no firewalls enabled, no filtering of any sort, then I would use a packet sniffer to see if the packets are actually on the network. This would take some know-how. Visit: anITKB.com, an IT Knowledge Base.

2 things: 1. I resolved the IP address conflict I mentioned earlier (roommate had a static IP set to that number) and I was able to ping and see all computers over the network *while the XP machine was cabled to the router.* 2. I had 2 wireless NICs in my XP machine. The old unused one used to give me problems where I would periodically lose connectivity, and I was experiencing some of those problems this time too. Even though it was disabled, I removed it from the machine entirely, and voila, everything started working perfectly. JM thanks for all your knowledge and patience. If you need anything just drop me a line and I'll definitely consider it.

no problem. Glad to hear that you worked out all of the issues... Visit: anITKB.com, an IT Knowledge Base.