SMB 1.0 support in Windows 10

mikeymikec

Lifer
May 19, 2011
17,577
9,268
136
I just sorted a problem for a customer that had me scratching my head for quite a while: Small business, network-connected photocopier and a bunch of Windows PCs. The photocopier is set up to send scanned documents via Windows filesharing services to whichever PC the user wants. The copier worked with all the other PCs except one. That one PC is running Win10 1809, newer than any of the others (some 1803, some Win7). That PC had no problem allowing other clients to connect but not the copier ("The network path cannot be found", said copier).

Long story short, I ran a packet sniffer and found the copier was in fact connecting to the PC in question, sent a negotiation packet which didn't include SMB support (in response to the problem I had configured the copier to use NTLM and port 445), and the PC responded by closing the connection. I then read up on enabling SMB 1.0 support, which did the trick.

What I'm puzzled about those is why this has only just become a problem. From what I've read, 1709 removed SMB 1.0 support yet here are 1803 PCs without any prior problems with the copier. I thought it might have been an 1809 change, but the copier definitely worked with that PC after the 1809 update. I even removed a cumulative update that occurred after 1809 that coincided nicely with the problem starting, still nothing.

Any ideas what might have triggered the problem?
 

mxnerd

Diamond Member
Jul 6, 2007
6,799
1,100
126
Last edited:

Iron Woode

Elite Member
Super Moderator
Oct 10, 1999
30,854
12,353
136
I had to intall the old SMB in order to get file sharing to work properly with my Linux server running Samba.
 

mikeymikec

Lifer
May 19, 2011
17,577
9,268
136
https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-by-default-in-windows

  • Windows 10 Home and Windows 10 Professional still contain the SMBv1 client by default after a clean installation. If the SMBv1 client is not used for 15 days in total (excluding the computer being turned off), it automatically uninstalls itself.

Microsoft can always find a way to screw you. How fantastic, isn't it? o_O

Now it works, now it doesn't. :eek:

oh ffs. Good catch, thanks.

MS said:
Automatic removal of SMB1 after 15 days is a one-time operation. If an administrator re-installs SMB1, no further attempts will be made to uninstall it.

At least there's that.
 
  • Like
Reactions: Iron Woode

Ketchup

Elite Member
Sep 1, 2002
14,545
236
106
That one ticked me off as well. Thank you Microsoft for making my simple network look so "uncool." One question: is there a constant timer on this one? So, if I turn on SMB 1.0, don't "use" it (whatever triggers their usage tracker) for 30 days, will it turn off again?
 

mikeymikec

Lifer
May 19, 2011
17,577
9,268
136
That one ticked me off as well. Thank you Microsoft for making my simple network look so "uncool." One question: is there a constant timer on this one? So, if I turn on SMB 1.0, don't "use" it (whatever triggers their usage tracker) for 30 days, will it turn off again?

See my last post :)