OT: Question about Windows 7...

[snowsnowsnow]

(Yes, totally off-topic, but this group can use the traffic)

I have a home network with a router and a couple dozen attached machine - some wired, some wireless.  A collection of Windows and Linux (and Android, etc) machines.

Everything works fine (except as noted below) - all the machine can ping each other and can reference each other by name (i.e., you can ping by machine name and the router will resolve it (it is the DNS server for the network)).

Most of the Windows machines run the stable Windows version (XP) and everything works as expected.  But one of them is running Windows 7 and it cannot ping the other machines, nor can they ping it.  The machine can ping to and/or connect to outside machines, but not to anything on the internal network.

Notes:
1) This has been and on-and-off problem for a long time, but now seems to have become permanent.  In the past, I was usually able to get it working by doing enough "pushing" (usually just a lot of pinging - until things started working again).  Now, that doesn't seem to help.

2) It *sounds* like a firewall issue, but I don't think it is.  Firewalls are well-known for blocking ICMP, but the thing is, I tried turning the Windows Firewall off (off completely), but it didn't help or change anything.

I've tried Googling and got lots of suggestions, but none of them did any good.

Any other ideas?

[td]

No suggestions nor any ideas.  I have a home network that sound similar to yours.  It has Windows 10, Windows 7 and Windows 2012R systems.  It also has several networked media, phone, IOT,  and printer devices. I think about 20 devices total.  That is not to mention several virtual machines running Linux and other versions of Windows on one of the Windows 10 systems.   Except for the virtual machines, they are all on the same subnet using switches and a WiFi router.  Assuming you mean 'ping' literally, I have no problems pinging any of the Windows devices form any of the other Windows devices.   I can image scenarios were  it might not work but it doesn't seem to apply in your case.

[snowsnowsnow]

I do remember reading somewhere that Windows 7, by design, doesn't "interoperate" with earlier (I think by "earlier", I mean, pre-Vista - since that's about where they changed everything) versions of Windows.  Has something to do with the "Homegroup" or something like that - but clearly, this is (at least from my point of view) just plain breakage.

In that reading, various possible fixes to this breakage are discussed, but (obviously, since I am still posting) none of them worked for me.

Given that you aren't running XP on your systems, you probably don't see this happening (i.e., all of your Windows systems are "post-breakage").

And if you are only running non-Windows systems (e.g., Linux) in virtual machines, then that also is consistent with the theory I am advancing.

Anyway, the beat goes on...

[td]

Since ping communicates over tcp/ip/ICMP, I don't know of any changes between OS's, other than firewall settings, that would prevent it from working between XP and Windows 7.  I have Windows XP 32 and 64 bit running in virtual machines at my home and the command shell ping command works between them (assuming it is allowed by firewall settings) and the physical Windows 10 and Windows 7 machines.  On the other hand, it does require a bit of fiddling to get MSFT's file sharing to work properly because MSFT changed the default configuration and the SMB protocol. 

As you might imagine the WindowWare in-house network has many machines running many different versions of Windows - including 'retired' versions of Windows like XP and 2003. I do know that I can ping the 'retired' systems from my Windows 10 notebook computer because scripts I use on the notebook do exactly that.  File sharing also works between those systems and Windows 10.

I am sure you already considered this but a network hardware problems can sometimes look like something else.  I had a wi-fi router causing inter machine communication problems awhile back.  It only appeared to affect one machine so I thought it was a port issue and switching ports seemed to help.  However, after a month or so the problem jumped to a wireless only video streaming device.  A bright shiny new router fixed the problem.   

[td]

To avoid any misunderstandings it should be noted that the ping command using NETBOIS names does not work across subnets unless WINS is enabled.  Obviously, you can use it with FQDNs and IP addresses without WINS.

[snowsnowsnow]

I think I've at least partially figured this out.

I should have mentioned at the outset that at least one machine *did* interop with the Window 7 machine.  But only one, until...

Note: The Win 7 machine is connected via wireless.

I did some more testing today and found that I could ping most of the wireless connected machines, but none of the wired machines.  Now, I note that many modern routers do implement some kind of isolation between the wired and the wireless clients; essentially, each group is kept separate from the other.  This is a feature in that if you have guests, you can give them your wireless password without giving them full access to your network.  That is, they can access the outside world and can access other wireless clients, but not your wired machines.  This is the behavior that I am seeing.

But here's the thing: it seems to be an interaction between features of the router and features of Windows 7 (and later) versions of Windows - i.e., post-breakage versions.  Because this "feature" doesn't kick in for any of my other machines (either non-Windows or Windows-but-pre-breakage).

As far as solutions go, I think there is a setting on the router to turn this "feature" off, but I haven't investigated this yet.  But it'd be better if there was a way to turn it off in Win 7 instead.  Note that thus must, at least in principle, be possible to do, since, as noted, only the Win 7 machine exhibits the behavior.

Another solution, of course, would be to connect the Win 7 machine wired instead of wireless, but I'd rather not do that.

[td]

You may already know all of this so please forgive if the following is just a waste of perfectly good electromagnetic radiation.  Generally, modern Wi-Fi routers have at least 2 SSIDs; some have 3 or more.  For example, my home Wi-Fi router is currently providing 3 SSIDs.  Two are for the 2.4 ghz and 5 ghz radios with full access to the wireless home network and the third is for the wireless guest network. 

It could be the case that your Windows 7 machine simply connected to the wrong SSID and therefore, the guest isolated virtual network instead of your full access network.   IIRC, Windows 7 does have automatic Wi-Fi connection features to assist the non computer networking savvy user base and you could have fallen prey to this 'helpful feature.' 

[td]

Another possibility is that if you happen to have Comcast as your ISP and use a Comcast gateway, you likely have their 'Hotspot' feature enabled.  Comcast Hotspot allows any Comcast customer in range of your device with an active Comcast account and a wireless device to use your bandwidth in isolation from your home network.  If you inadvertently connect to the hotspot instead of one of your home network SSIDs, you would have Internet access but not home network access.

[snowsnowsnow]

It could be the case that your Windows 7 machine simply connected to the wrong SSID and therefore, the guest isolated virtual network instead of your full access network.   IIRC, Windows 7 does have automatic Wi-Fi connection features to assist the non computer networking savvy user base and you could have fallen prey to this 'helpful feature.'

Yes, this turns out to have been it (modulo some details which I won't go into at the moment).  So, this thread wasn't a waste of time after all...

The root problem is that by default, the router has all the networks named the same, so it's random (at least in theory) which actual network a machine will connect to.  When I changed the names (SSIDs) so that they were all distinct, the problem went away.

Still, it seems odd that only the Win 7 machine was affected - which made me think it was something unique to Win 7 - but now I'm beginning to think it was something specific to the hardware upon which Win 7 was running, rather than Win 7 itself, that caused the problem.  That said, I do also think that your comment about "falling prey" to this "helpful feature" is relevant as well.

P.S.  Re: Comcast.  No, I don't have Comcast, but I am familiar with the "Hotspot" feature to which you refer.

[td]

At least you got it figured out.