Recent trouble connecting to SMB share from Windows client or Ubuntu client

I have an old PC that I use as a server. It mostly is used for serving up Plex and family photos/videos - just three SATA drives attached for storage. The machine runs Ubuntu Server 22.04.2 installed on SATA A ... personal files on SATA B and C. It is not connected to a display, so I use PuTTy to manage it from my Windows 11 PCs.

Everything was working on it perfectly for a year or more, when last week I lost the ability to mount SATA A or B using the "Map Network Drive" features from my Win11 machines. I started poking around, tried to use online forums and reddit posts to self diagnose, but I'm stuck. Here's what I know.

The /etc/samba/smb.conf file seems to be setup correctly. testparm dumps this

user@optiserver990:~$ testparmLoad smb config files from /etc/samba/smb.confLoaded services file OK.Weak crypto is allowedServer role: ROLE_STANDALONEPress enter to see a dump of your service definitions# Global parameters[global]        auto services = global        bind interfaces only = Yes        client max protocol = SMB3        interfaces = lo eno1        log file = /var/log/samba/log.%m        logging = file        map to guest = Bad User        max log size = 1000        obey pam restrictions = Yes        pam password change = Yes        panic action = /usr/share/samba/panic-action %d        passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .        passwd program = /usr/bin/passwd %u        server role = standalone server        server string = %h server (Samba, Ubuntu)        unix password sync = Yes        usershare allow guests = Yes        idmap config * : backend = tdb[printers]        browseable = No        comment = All Printers        create mask = 0700        path = /var/spool/samba        printable = Yes[print$]        comment = Printer Drivers        path = /var/lib/samba/printers[TERADRIVE]        path = /media/TERADRIVE        read only = No[DECATERA]        path = /media/DECATERA        read only = No[HOME]        comment = user's home directory on Optiserver990        path = /home/user        read only = No

I cannot connect to any of the defined 'TERADRIVE''DECATERA' or 'HOME' shares. When I am connected via SSH, I can use smbclient to list shares and I get this.

user@optiserver990:~$ smbclient -L 10.0.0.5Password for [WORKGROUP\user]:        Sharename       Type      Comment        ---------       ----      -------        print$          Disk      Printer Drivers        TERADRIVE       Disk        DECATERA        Disk        HOME            Disk      user's home directory on Optiserver990        IPC$            IPC       IPC Service (optiserver990 server (Samba, Ubuntu))SMB1 disabled -- no workgroup available

I noticed the line SMB1 disabled -- no workgroup available, so I poked around and saw various people online say to enable SMB1 protocol on the Windows client side via "Enable Optional Features" ... that did not fix my problem. Other people said to add lines to /etc/samba/smb.conf setting various max and min SMB protocol versions. That also did not fix my problem.

One thing I can do is I seem to be able to use smbclient to connect to the share. Now, that is all via PuTTy'ing into the server, so maybe it's just that I'm connecting the server to itself?

Anyhow, this is what I get and I thought it at least verified that Samba is up and configured properly.

user@optiserver990:~$ smbclient \\\\10.0.0.5\\DECATERA -m SMB3Password for [WORKGROUP\user]:Try "help" to get a list of possible commands.smb: \> dir  .                                   D        0  Sun Jul  2 10:08:41 2023  ..                                  D        0  Mon Oct 17 14:16:51 2022  SABnzbd complete                    D        0  Fri Dec 15 19:54:02 2023  Movies                              D        0  Fri Nov 17 21:46:43 2023  TV-Shows                            D        0  Fri Oct  6 21:00:00 2023  HelloWorld.txt                      A      242  Wed May 17 22:52:05 2023  lost+found                          D        0  Mon Oct 17 14:24:57 2022  SABnzbd incomplete                  D        0  Fri Dec 15 19:54:02 2023                7751273184 blocks of size 1024. 4576001592 blocks available

It also works if I leave off the -m SMB3 option, or if I pass -m SMB2. I tried -m SMB1 and it said:

WARNING: Ignoring invalid value 'SMB1' for parameter 'client max protocol'.

When I'm connected this way, it does show up as an active connection inside of Webmin's Samba panel.

Confusingly, if I pass smbstatus --shares I get a bunch of nothing.

user@optiserver990:~$ sudo smbstatus --shares[sudo] password for user:Service      pid     Machine       Connected at                     Encryption   Signing---------------------------------------------------------------------------------------------

Lastly, I tried to connect from an Ubuntu client, just to isolate the issue. It also did not work.

ubuntu@ubuntu:~$ smbclient -U user //10.0.0.5/TERADRIVEPassword for [WORKGROUP\user]:do_connect: Connection to 10.0.0.5 failed (Error NT_STATUS_IO_TIMEOUT)

Everything else is working well - I can use other machines to connect to programs like Webmin, Sabnzbd, etc. Plex is playing movies. SSH is working.

I just don’t have GUI access to mounted shares from the Windows client side.