The vagaries of networking

I am not sure if I really expect an answer to this as I am not providing any useful information to help someone do so! Call it a frustration post!

Can anyone explain why I can get the three PC/laptops to talk to each other one day, yet another day one or other has the sulks and hides, and today, none of them can see a network at all. I haven't touched anything - honest!

WiFi works, internet works, individual PCs/laptops work, I work, even the dog does.

It's just this B.....y network that doesn't.

I think I need Harry Potter. Networking is a black art

The standard items to check are:
1. Four services that need to be started automatically (as of v1809 this should be the default)
>> Function Discovery Host Provider
>> Function Discovery Resource Publication [this is set as "Automatic (Trigger Start)]
>> SSDP Discovery
>> UPnP Device Host

2. If you still have issues, then:
>> Go to "Control Panel" > "Programs and Features" > "Turn Windows features on or off"
>> Under "SMB 1.0/CIFS File Sharing Support", make sure that "SMB 1.0/CIFS Client" is checked.
>> Restart router, then all systems.

3. If issues still persist and your router has the capability of serving as the "Master Browser", set the router as such and restart everything.

JohnD

Basically it's simple windows doesn't look for network PC's it asks the master browser on the network for a list. The mb is just any PC on the network normally the first one turned on that day it will scan the local subnet for PCs to add to the list. It may not find any as you turn on another PC it may take 20mins before the mb rescans in the meantime it won't be seen.

The secret is that only applies to PC via name if you try and connect via IP it goes direct and works

Thank you both. Samuria's comment is particularly interesting as my wife usually switches on her PC earlier than I do. If this is an issue then John's suggestion re making my router master browser may help. It's the standard BT issue so will need to check to see if it has that capability.

I'll also check out the other suggestions.

Sorry - In the UK BT would automatically be assumed to mean the UK telephone system supplier British Telecom. They supply broadband and a router when you pay them enough money!

Compumind said:

@Sigurd -
1) Are the version numbers of Windows 10 all the same on each PC?
2) Have you "cold" rebooted your Modem and Router? Turn off all PC's first. Cold reboot Modem and then your Router. Then restart one PC at a time.
3) Are any of those machines "locked down" corporate laptops with McAfee Endpoint Security or Norton Endpoint Security?

1 - Yes
2 - I haven't tried that - will do.
3 - These are all personal machines with my having total access.

- - - Updated - - -

Berton said:

Thanks, I missed seeing your flag.

As I missed yours and assumed we spoke the same language.

To quote GB Shaw "Two countries separated by a common language"!

You are beating a dead horse...SMBv1.

Microsoft has been recommending that you disable the vulnerable SMBv1 protocol for ages. Recent ransomware outbreaks underscore the need to take this important step. This is OLD news.
Master Browser needs SMBv1 to run. Microsoft deprecated the SMBv1 protocol in 2014, and (if installed and depending on the installation of Win10) will remove it if not used for 15 days. Because the Computer Browser service relies on SMBv1, the service is uninstalled if the SMBv1 client or server is uninstalled. This means that Network Explorer can no longer display Windows computers through the legacy NetBIOS datagram browsing method. You can re-install SMBv1 and play Russian Roulette.

See Solving Network and Sharing Problem Window 10 v1803 OS Build 17134.137 - Microsoft Community

Microsoft now suggests an alternate method that uses the WS-DISCOVERY protocol. Now it turns out that this protocol is also horribly insecure - it's a UDP-based protocol, meaning the packet destination can be spoofed and can be abused to amplify distributed denial-of-sevice (DDoS) attacks. This is fresh news - this month.

So they give you 2 choices you can theoretically use, neither of which works well.

Microsoft evidently does not want you to have a local network that functions easily and simply. They want you to use their cloud as your network and pay for the 'privilege'.