[Milhouse]

I mis-remembered the Samba version in FreeNAS 8.3.x, it is also Samba 3.6.12.

This version of Samba server only supports SMB2_02 which is a very old sub-protocol of SMB2. It certainly does not support SMB3.

When you configure SMB2 as the "Minimum protocol version" in the Kodi GUI (Settings > Services > SMB Client), this is configuring Samba with an alias (SMB2), which in Samba 4.x (ie. the version of the client Samba libraries used by LibreELEC) is mapped to sub-protocol SMB2_10 (SMB 2.10, Windows 7 SMB2 version) SMB2_02.

There are many versions of SMB sub-protocol, and the interpretation of the SMB2 alias may differ depending on the version of Samba client/server being used - for example SMB2 on your 3.x server maps to what became known as SMB2_02 (sub-protocols don't actually exist in 3.6.x).

Potted Samba history:

Samba 3.5.0 is the first 3.x release with experimental SMB2 support (sub-protocols weren't a thing at this time). There is no SMB3 support in 3.x.
Samba 4.0.0 introduces SMB2_10 (alias SMB2), the concept of sub-protocols (ie. SMB2_02), and initial SMB3/SMB3_00 support.
Samba 4.3.0 introduces SMB3_11 (the current default for the SMB3 alias).

When configuring a Samba 4.x client and Samba 3.6.x server to both use client/server min protocol = SMB2, the client will not be able to connect to the server - by selecting SMB2 you're selecting a sub-protocol on the client (SMB2_10) that is not supported by the server. The same is also true with SMB3 when mixing Samba 4.3.0+ client with a 4.x server version prior to 4.3.0.

Fortunately, the solution is fairly simple. Configure the min/max protocol in Kodi as follows:



This will default Samba to client min protocol = SMB2 and client max protocol = SMB3 (the default "most common"/"best" min/max supported by the underlying Samba 4.11.x libs in LibreELEC) without adding the options to /storage/.kodi/.smb/smb.conf (note that this step isn't essential, as the next step should override whatever minimum protocol is set, but makes life a bit easier).

Then create /storage/.kodi/.smb/user.conf with the following line:

text:


client min protocol = SMB2_02

which should allow a Kodi client to connect to a Samba 3.6.12 server using a minimum sub-protocol of SMB2_02.

Let me know if that helps...