SMB. protocol version mismatch between client and server

Authority mappings

Which work roles, knowledge units, and EWU courses this error pattern touches. Hover for context, click to drill in.

What the message means

The SMB handshake failed because client and server can't agree on a protocol version. Modern Samba defaults to SMB3 but some scoring engines or older clients only speak SMB1 (NT1). The fix is to widen your min protocol.

Why the service is down

• smb.conf sets `min protocol = SMB3` or similar. too restrictive.
• The scoring-engine client is stuck at an old version.
• Encryption setting forces a version the client doesn't support.

Commands in order

1. 1. 1. Check current min/max protocol

   copy testparm -s 2>/dev/null | grep -iE 'min protocol|max protocol|server min'

   Expect

   server min protocol = NT1 or SMB2

   Interpret and next

   If nothing printed, defaults are in effect (Samba 4.11+ defaults to SMB2).
2. 2. 2. Lower min protocol for compatibility

   copy # edit /etc/samba/smb.conf, under [global]: server min protocol = NT1 client min protocol = NT1

   Expect

   File saved without syntax error

   Interpret and next

   Re-run testparm. If errors: remove the new lines, check spelling.
3. 3. 3. Restart Samba and retest

   copy systemctl restart smbd smbclient -L //localhost -U keons

   Expect

   Share list appears without 'protocol error'

   Interpret and next

   Still fails = try removing `smb encrypt`/`smb signing` strict settings, or check `ntlm auth = yes`.

Decision tree

Answer each question to route to the right fix.

External references

• NCAE Cyber Games. official rules and scoring
• Samba smb.conf(5). protocol settings

Other patterns on this service

• 4,415.3 failure SMB operation failed: [Errno 111] Connection refused
• 1,705.6 partial SMB operation failed: Failed to get attributes for addict_with_a_pen.data on files: Unabl.
• 1,197.2 failure SMB operation failed: [Errno 113] Host is unreachable
• 525 partial 22 files have incorrect content
• 262.5 partial SMB operation failed: Failed to get attributes for cottonwood.data on files: Unable to op.
• 105.6 partial SMB operation failed: Failed to retrieve before_you_start_your_day.data on files: Unable .
• 68.1 partial SMB operation failed: Failed to get attributes for .choker.data on files: Unable to open .
• 63.9 partial SMB operation failed: Failed to get attributes for air_catcher.data on files: Unable to o.
• 63.9 failure Failed to connect to host: IP
• 56.9 partial SMB operation failed: Failed to get attributes for addict_with_a_pen.data on files: Unabl.