[Samba] Windows clients connecting to SMB share differently over IP than DNS

[Jeremy Allison]

On Thu, Apr 01, 2021 at 10:51:53AM -0700, Gavin Greenwalt via samba wrote:
>>It might help if the OP did two things:
>>Upgrade Samba, 4.4.16 is very old and EOL.
>>Post their smb.conf, at the moment we have no idea how they are running Samba.
>>
>>Rowland
>
>Unfortunately I'm locked into 4.4 because that's what Synology is
>using in DSM.  But my next step will be to spin up a fresh VM of
>Ubuntu and compare a clean installation of 4.4.16 to see if Synology
>DSM is somehow introducing the slowdown.
>
>smb.conf (sanitized) >
>[global]
>        printcap name=cups
>        winbind enum groups=yes
>        include=/var/tmp/nginx/smb.netbios.aliases.conf
>        password server=3.3.3.100
>        encrypt passwords=yes
>        admin users=@DOM\Domain Admins, at DOM\Enterprise Admins
>        min protocol=SMB2_10
>        security=ads
>        local master=no
>        realm=DOMAIN.COM
>        syno sync dctime=yes
>        passdb backend=smbpasswd
>        ldap timeout=60
>        printing=cups
>        max protocol=SMB3
>        winbind enum users=yes
>        load printers=yes
>        workgroup=DOM
>
>smbinfo.conf >
>[global]
>    rpc_server:mdssvc=external
>    prev domain=DOM
>    server signing=yes
>    veto files=
>    advanced_domain_option=yes
>    smb2 leases=yes
>    btrfs clone=no
>    winbind expand groups=1
>    register nic=bond1
>    rpc_daemon:mdssd=fork
>    enable nt4 enum=no
>    allow insecure widelinks=no
>    disable shadow copy=no
>
>smb.share.conf >
>[Share]
>        recycle bin admin only=yes
>        ftp disable modify=no
>        ftp disable download=no
>        write list=nobody,nobody
>        browseable=yes
>        mediaindex=no
>        hide unreadable=no
>        win share=yes
>        enable recycle bin=yes
>        invalid users=nobody,nobody
>        read list=nobody,nobody
>        ftp disable list=no
>        edit synoacl=yes
>        valid users=nobody,nobody
>        writeable=yes
>        guest ok=yes
>        path=/volume1/Share
>        skip smb perm=yes
>        comment="Share Directory"

There are some Synology-specific parameters
in there, which maeans you're running a modified
version of Samba.

I'm not sure if the problems you're seeing are
related to that, but this certainly isn't a stock
4.4.16.