Very weird problem accessing Synology NAS using Windows File Explorer

[MrJim]

I changed ISP a while ago, and ever since then, I've not been able to access the files on the NAS using Windows File Explorer. Before changing ISP, file access was working fine.

I'd actually pretty much forgotten about the problem, as these days I don't need file access all that often. Just out of curiosity, I tried accessing the files from File Explorer just now, & it worked! Then I realised that I had my VPN (Private Internet Access) switched on. So I switched the VPN off, and now I can't access the files once again! The network error box pops up saying that Windows can't access \\diskstation, with the error code '0x80070035'.

Checking the network settings in DSM 6.2, the network is obviously connected (I can access the NAS through the web interface without problems). I have the internal IP address manually set to 192.168.0.2, and the router (default gateway) is set to 192.168.0.1 using IPv4. I don't have the NAS set up for external access as I don't need it.

Can anyone shed any light on what's going on? I'm a bit bemused!

[[GSV]Trig]

Havent used DSM, but do you have SMB enabled on your machine?

[Jonatron]

Does \\192.168.0.2 work instead of \\diskstation ?

[MrJim]

Havent used DSM, but do you have SMB enabled on your machine?

Yes, SMB is enabled in 'File Services'.

Does \\192.168.0.2 work instead of \\diskstation ?

Using \\distsation in Windows File Explorer doesn't work, unless the VPN is active. Otherwise, I get the error I described previously, & in Chrome I get a 'Your file couldn't be accessed' message. Using just the IP address in both File Explorer & Chrome brings up the web interface to the NAS.

[[GSV]Trig]

Yes, SMB is enabled in 'File Services'.

I didn't mean in services on the NAS, I meant on your machine, a few years back I think it was SMB was disabled by default, you have to add it as a feature now within Windows.

[Apex]

change of isp = change of router ?

[MrJim]

I didn't mean in services on the NAS, I meant on your machine, a few years back I think it was SMB was disabled by default, you have to add it as a feature now within Windows.

Ah, sorry I misunderstood. Yes it is enabled - as I said, when the VPN is active I can access the files on the NAS using Windows File Explorer without issues.

change of isp = change of router ?

Yes it was a change of router. Although when I said 'change of ISP', it was really just a change of service; I stayed with BT, and change the router for what seems to be an identical one. I thought I'd kept all the settings to same as before.

Just out of curiosity, what exactly doe activating a VPN do? I thought all it did was to change the external IP address to whichever country you select, & encrypt the data you exchange thereafter? I just wonder what else could be changing to might affect file access to my NAS?

[Jonj1611]

Doesn't it also change the DNS?

[Jonatron]

Yes, SMB is enabled in 'File Services'.



Using \\distsation in Windows File Explorer doesn't work, unless the VPN is active. Otherwise, I get the error I described previously, & in Chrome I get a 'Your file couldn't be accessed' message. Using just the IP address in both File Explorer & Chrome brings up the web interface to the NAS.

There's a difference between putting \\192.168.0.2 and 192.168.0.2 in file explorer. What does the former do?

[[GSV]Trig]

Yes it was a change of router.

Erm, does your machine think that you have connected to a different network and has firewall setup for a public network so its turned off and/or blocked access to stuff...

[MrJim]

There's a difference between putting \\192.168.0.2 and 192.168.0.2 in file explorer. What does the former do?

Oh well that's interesting - putting \\192.168.0.2 worked! Thank you so much! Just out of curiosity, what difference does the \\ make?

[Jonatron]

I needed to google path formats, but according to https://learn.microsoft.com/en-us/do...mats#unc-paths :

UNC paths

Universal naming convention (UNC) paths, which are used to access network resources, have the following format:

A server or host name, which is prefaced by \\. The server name can be a NetBIOS machine name or an IP/FQDN address (IPv4 as well as v6 are supported).
A share name, which is separated from the host name by \. Together, the server and share name make up the volume.
A directory name. The directory separator character separates subdirectories within the nested directory hierarchy.
An optional filename. The directory separator character separates the file path and the filename.

The following are some examples of UNC paths:
Path Description
\\system07\C$\ The root directory of the C: drive on system07.
\\Server2\Share\Test\Foo.txt The Foo.txt file in the Test directory of the \\Server2\Share volume.

UNC paths must always be fully qualified. They can include relative directory segments (. and ..), but these must be part of a fully qualified path. You can use relative paths only by mapping a UNC path to a drive letter.

[MrJim]

I needed to google path formats, but according to https://learn.microsoft.com/en-us/do...mats#unc-paths :

UNC paths

Universal naming convention (UNC) paths, which are used to access network resources, have the following format:

A server or host name, which is prefaced by \\. The server name can be a NetBIOS machine name or an IP/FQDN address (IPv4 as well as v6 are supported).
A share name, which is separated from the host name by \. Together, the server and share name make up the volume.
A directory name. The directory separator character separates subdirectories within the nested directory hierarchy.
An optional filename. The directory separator character separates the file path and the filename.

The following are some examples of UNC paths:
Path Description
\\system07\C$\ The root directory of the C: drive on system07.
\\Server2\Share\Test\Foo.txt The Foo.txt file in the Test directory of the \\Server2\Share volume.

UNC paths must always be fully qualified. They can include relative directory segments (. and ..), but these must be part of a fully qualified path. You can use relative paths only by mapping a UNC path to a drive letter.

Thanks very much for going to the trouble of looking up the convention for UNC paths. The odd thing is, typing \\diskstation wasn't working initially (without the VPN working), but once I tried \\192.168.0.2 as you suggested, it does now work. I don't quite understand why that should be the case, but I'm happy it's working all the same!

[Jonatron]

Guessing based on "The server name can be a NetBIOS machine name or an IP/FQDN address (IPv4 as well as v6 are supported)." that NetBIOS is disabled.
There's a few windows settings that need to be right, and matching on different machines for windows to be able to find the IP address of \\diskstation
There's a whole bunch of different things in different places in windows to check: https://superuser.com/questions/1240...can-by-localho

[Apex]

NetBIOS turned off on the new router, the master browser election not working till you went to it via the ip and then it decided to sort itself out; frankly the fact any of it works at any time is a blessing.

[badass]

NetBIOS turned off on the new router, the master browser election not working till you went to it via the ip and then it decided to sort itself out; frankly the fact any of it works at any time is a blessing.

I'd be highly surprised if a home router has anything to do with NetBIOS. Realistically the only setting a home router might influence is via DHCP - however I doubt those DHCP options will be present as configurable. If the option is missing, Windows defaults to on (certainly my Windows 10 does. Win11 might not)