====== Fedora 31 で protocol negotiation failed が発生する ======
Fedora 31 で Samba のファイル共有にアクセスできない場合は以下の確認を行ってみる。\\

===== smbclient コマンドによる確認 =====
<code>
$ smbclient -L 192.168.1.254 -U% -m SMB2
protocol negotiation failed: NT_STATUS_CONNECTION_DISCONNECTED
</code>

===== testparm コマンドによる確認(クライアント側 Fedora 31) =====
<code>
$ testparm -v | grep protocol
Load smb config files from /etc/samba/smb.conf
Loaded services file OK.
Server role: ROLE_STANDALONE

Press enter to see a dump of your service definitions

	client ipc max protocol = default
	client ipc min protocol = default
	client max protocol = default
	client min protocol = SMB2_02
	server max protocol = SMB3
	server min protocol = SMB2_02
</code>

===== クライアント側の Fedora 31 の設定変更 =====
Samba の設定に以下(**client min protocol = NT1**)を追記する。\\
<code>
$ sudo vi /etc/samba/smb.conf
</code>
<file /etc/samba/smb.conf>
[global]

;       max protocol = SMB2
        client min protocol = NT1

</file>
<code>
$ testparm -v | grep protocol
Load smb config files from /etc/samba/smb.conf
Loaded services file OK.
Server role: ROLE_STANDALONE

Press enter to see a dump of your service definitions

	client ipc max protocol = default
	client ipc min protocol = default
	client max protocol = default
	client min protocol = NT1
	server max protocol = SMB3
	server min protocol = SMB2_02
</code>

===== 再度 smbclient コマンドによる確認 =====
共有が確認できれば、アクセスエラーは回避できている。\\
<code>
$ smbclient -L 192.168.1.254 -U% -m SMB2

	Sharename       Type      Comment
	---------       ----      -------
	IPC$            IPC       IPC Service (GL-AR750S-d80)
	sd128gb         Disk      
Reconnecting with SMB1 for workgroup listing.

	Server               Comment
	---------            -------
	GL-AR750S            GL-AR750S-d80

	Workgroup            Master
	---------            -------
	MONSTERS-G           GL-AR750S
</code>

===== 参考文献 =====
[[https://ask.fedoraproject.org/t/fedora-31-fails-to-retrive-shares/4038/37|Fedora 31 fails to retrive shares - Discussions in English / on using Fedora - Ask Fedora]]\\