Cannot see anything except Win7 boxen in Explorer

[PeterD]

Hello all,
I have two severe issues that are related. One affects every Win7 machine, the second only one of them (which I made worse trying to troubleshoot the first issue from it and reversing the steps failed to solve it...more on this later).

The main issue is that I can't see anything except other Win7 machines when I go in to Explorer under NETWORK (within the "computers" section that is -- printers, media devices, scanners, etc, show up fine). This has been going on for months, and I'm betting a patch did something that screwed everything up.

What I should be seeing, in addition to the Win7 boxen, are my NAS server (running some variant of Linux), two Macs, a Linux media server and several servers running in VMs (2003 and 2008). I can't see any of these from any of the Windows 7 boxen.

In addition, on ONE of these machines, in my futile attempt to troubleshoot this problem, I now see nothing at all under "Network" in the explorer. No computers, no printers, scanners, media devices, nothing. Totally blank (i.e., in the image below, there would be nothing at all in there).

I've searched hi-and-low for answers and tried all the usual tricks. Namely:

1. DNS cache flushed
2. All networking-related services are started and running. I restarted the browser services on all machines.
3. permissions set for LM & NTLM, plus the requirement to use 128-bit encryption has been disabled in the local security policy.
4. Network discovery has been turned on in Advanced sharing settings, and a requirement for a password has been turned off in the same menu.
5. I even rebuilt the TCP/IP stack.
6. I left and rejoined the correct workgroup (HOME workgroup).

Nothing I've seen in other similar threads has worked.

I can ping everything on the network, I can connect using an IP Address and I can also connect if I put in the UNC path (\\server\media). I just cannot browse the network for anything other than Win7 computers. Here is a screenshot of my network, showing only three computers, where there should be at least 7 or 8 visible at any one time.

Thanks in advance. Any and all efforts are greatly appreciated.

 

[2xg]

Hi Peter and Welcome to Seven Forums,

Have you also verified that the Link Layer Topology Discovery (LLTD) protocol is enabled on the network adapters of the problematic computers?
You might also want to go through the troubleshooting tips from this link.

Please post an update.

 

[cyclic]

Have you thought of running the network setup wizard ?

 

[PeterD]

Hi Peter and Welcome to Seven Forums,

Have you also verified that the Link Layer Topology Discovery (LLTD) protocol is enabled on the network adapters of the problematic computers?
You might also want to go through the troubleshooting tips from this link.

Please post an update.

LLTD is enabled on all machines (both tick-boxes checked). All computers are connected to a private (home) network (i.e. not a "public" network for firewall purposes).

Where is the setup wizard located? I'm willing to try that, but I have my doubts <g>. I've run all the different troubleshooters and nothing seems amiss. If this was only happening on ONE machine I would be less concerned, but it's happening on all the Win7 boxen and my Win 2K8 server on the VM. EXCEPTION: One VM (server 2k3) sees everything, exactly as others should, but it's host (the machine I'm typing this on) cannot. Gaaaah.

I'm using a 192.168.0.x network with a 255.255.255.0 subnet. Desktops and VMs have static IPs. Laptops and printers have DCHP-assigned addresses, all assigned from one WRT-54g router. The only firewall present is whatever Windows configured when the OS was installed (it was never tinkered with).

Please, guys, help save what's left of my sanity. This is by far the most frustrating networking issue I've ever faced. Thanks in advance.

 

[Solidwave]

IIRC, Win7 won't see workgroup-style network shares if homegroup functionality is enabled. Homegroups are for pure Win7 LANs--they don't work with mixed networks. Leave the homegroup or disable both homegroup services and see if that helps.

 

[PeterD]

Tried it with Homegroups enabled and disabled and no change (reboots after each change).

 

[PeterD]

OK, progress!
It's a firewall issue for sure. I dropped the firewall on the one problem Windows7 PC (the one that had nothing in its Network window last night) and suddenly every machine can see most, if not all Workgroup resources. I re-enabled the Firewall, refreshed on all machines after about a half-hour and things were back to the way they were (except the problem machine got its Network icons back, although only for the Win7 computers).

So where, within the firewall settings, should I be looking? I obviously can't run without the Windows FW. And now I'm really curious as to which program or "fix" disabled the appropriate firewall settings?

 

[2xg]

I'll be looking what needs to be excluded in your Windows Firewall. Mine has File and Printer Sharing, Homegrop & Network Discovery excluded.

 

[PeterD]

I find the firewall interface a little beyond my grasp (which is why I've generally left it alone). Might I ask you to help me understand the settings in there a little better?

 

[2xg]

Here's the location: Control Panel\System and Security\Windows Firewall\Allowed Programs. Check the box on what's need to be excluded or to be allowed, as I've mentioned in my previous post.

 

[PeterD]

I have a lot more than those three in there, and all three of those mentioned were checked. I also activated the Netlogon Service (since one of the servers on the LAN will eventually become a Domain Controller, as I play around with and learn Active Directory over the next few months). I also allowed Peer to Peer Collaborations Foundation Properties. Everything saved, system rebooted and...SUCCESS.

I'm not sure what went wrong, but as of now it looks good from pretty well all my machines, including the home theatre box and both VMs.

Thanks to one and all. If anybody has an idea on what might have changed I'd like to make note of this as well. Happy 2012 all (and GO GIANTS <G>)

 

[2xg]

Great to hear that all is sorted.

You're Welcome Peter.

 

[PeterD]

Unfortunately, that wasn't the problem. Now 4 hours later everything's back the way it was. Once again I ran full scans and found nothnig.

However, something said a while ago looks like it may be an issue. IPv6. When I disable IPv6 I can see everything. It seems that the systems are looking first for an IPv6 connection and not going any further and also looking for IPv4 NICs. What's odd is that I disabled it earlier today and it's back now. What's even odder is that this one machine having IPv6 enabled buggers up the entire network. I've not changed any adapter settings on the other boxen, just this one.

Any thought on how to keep IPv6 support from re-enabling itself, why it IS re-enabling itself in the first place and why only one computer using this protocol is messing up all the other Win7 boxes on the LAN?

 

[Solidwave]

If you want to learn to be a professional sysadmin--which is the impression I get from your wanting to setup a domain to learn on--one of the skills you need to cultivate is knowing how to isolate complex issues into simple problems so know where to start when you're confronted with something that doesn't have a ready-made solution listed in the MS KB or on Technet.

Break this one down further to isolate where the problem is. If it was my network, I'd try a few things like this:

Can your XP boxes see each other? Can they see themselves on their own list of networked computers? If not, then the problem is on the XP boxes.

What happens if you connect one XP box and one W7 box using a crossover cable? Do they see each other? If so, then something else on your network is interfering with sharing.

What happens if you set up DHCP, DNS and WINS servers on the network instead of using static addressing?

What happens if you disconnect all computers that are going into IPv6 mode? Does that make the rest of the network work properly?

Troubleshoot why some of your computers are reenabling IPv6 autonomously.

What happens if you get two empty hard drives and swap out your existing HDs from two computers and install fresh copies of XP and W7 on two computers? If you connect the two new installs with a crossover cable, can they see each other? If they don't see each other out of the box, then you have either made a configuration error or the installation images you're using are damaged. What if you connect the two test PCs to your network switch? What if you start installing the software and utilities you usually install on all your systems without thinking about it too much? Do they stop seeing each other after you install a certain program?

If you do all of this, I'm pretty sure you'll be able to isolate the problem down from 'my network doesn't work' to 'my network doesn't work when ________,' and that's something much easier to solve.