Yesterday I was rebooting my machine after installing a new monitor, and noticed that my Tomato router giving errors about not being able to access its CIFS/Samba mount on my desktop, which is where I have it store its logs. The error I kept getting was:

kernel:  CIFS VFS: cifs_mount failed w/return code = -5

Turns out that at some point, Samba changed the default minimum allowed server protocol to allow only newer clients. This is probably fine for 99.99% of use cases out there, but for someone like me running old Tomato on my poor Linksys WRT54GL, it caused a problem.

The particular setting in question was server min protocol changing its default from NT1 to SMB_02. So in my smb.conf, my [global] section now has these two extra lines for backwards compatibility with Tomato:

    ntlm auth = ntlmv1-permitted
    server min protocol = NT1

In case anyone cares what a share setting for Tomato’s CIFS mounting might look like:

    comment = tomato router
    path = /home/tomato
    valid users = tomato
    read only = no