SMB1 for HEOS on Ubuntu Focal

Last weekend I updated my ZFS NAS from Ubuntu 18.04.5 LTS (Bionic Beaver) to Ubuntu 20.04.1 LTS (Focal Fossa). However, after the update, my HEOS speakers refused to play any music. After some tinkering, I was able to resolve this by re-enabling SMB1 or actually NT1 support.

Cause

After some research, I quickly had a hunch that this was caused by the SMB upgrade which was, luckily, clearly mentioned in the Focal releasnotes.

Unfortunately, the HEOS documentation contained no indication that SMB2 or higher was unsupported. After a long search I ended up at forum about using HEOS with FreeNAS. Luckily the lack of support for more recent SMB versions was reported by other users as well and it even contained quoted feedback from the Denon support:

Response By Email (Michael M from Customer Service) (04/17/2020 09:45 AM)

Hello Bill,

Thank you for your email. The Network Shares feature from the HEOS App currently requires SMB 1.0 enabled on the PC or Media Server. We understand SMB 1.0 has depreciated and can pose a security risk, so we are planning on updating the SMB requirement in the near future via a firmware update.

Thank You, HEOS Support Team

Knowing the problem it was now time for a solution.

Solution

Luckily the release notes of Samba 4.11.0 included a hint in the section 'SMB1 is disabled by default'. The server min protocol had to be changed.

However, I had no idea what the correct option was. There is no option SMB1. Luckily in the example of the SMB-client parameters, there was another piece of information. Besides that, I found the following StackOverflow question about NT1 / SMB1 clients. Thus, NT1 should/could be used instead.

Therefore, I ended up with the following fragment in the [global] section of the config.

# Allow SMB1 for HEOS
server min protocol=NT1

After that a quick restart was executed:

$ sudo service smbd restart

Finally, I was able to enjoy my music again.

Conclusion

Denon is using an old/deprecated SBM version for there HEOS system and failed to document this properly. Luckily, both Ubuntu and Samba created decent release notes which allowed for a quick problem resolution.