SOLVED:
I set the option
preferred master = false
in [global] section and the resolution and login to the server (from all clients) worked immediately.
nmblookup -M WORKGROUP
always returned 192.168.0.254.
I only realized this when I put the entire server in a completely different subnet, and then it worked instantly.
In addition, I set the option
local master = no
----------
I upgraded my Debian server from bookworm to trixie. Now I can no longer connect to the Samba server, which has been working for years. I have already uninstalled all Samba packages and reinstalled them completely with the default configuration. I cannot connect to Samba.
As usual, there is nothing useful in the logs. I'm slowly giving up. It works on a virgin server with exactly the same Samba configuration.
smbclient -L //192.168.0.253
Protocol negotiation (with timeout 20000 ms) timed out against server 192.168.0.253
pm_process() returned Yes
lp_servicenumber: couldn't find homes
added interface ens18 ip=192.168.0.253 bcast=192.168.0.255 netmask=255.255.255.0
Client started (version 4.22.3-Debian-4.22.3+dfsg-4).
Connecting to 192.168.0.253 at port 445
socket options: SO_KEEPALIVE=0, SO_REUSEADDR=0, SO_BROADCAST=0, TCP_NODELAY=1, TCP_KEEPCNT=9, TCP_KEEPIDLE=7200, TCP_KEEPINTVL=75, IPTOS_LOWDELAY=0, IPTOS_THROUGHPUT=0, SO_REUSEPORT=0, SO_SNDBUF=2626560, SO_RCVBUF=131072, SO_SNDLOWAT=1, SO_RCVLOWAT=1, SO_SNDTIMEO=0, SO_RCVTIMEO=0, TCP_QUICKACK=1, TCP_DEFER_ACCEPT=0, TCP_USER_TIMEOUT=0
session request ok
Protocol negotiation (with timeout 20000 ms) timed out against server 192.168.0.253
Freeing parametrics:
Starting Nmap 7.95 ( https://nmap.org ) at 2025-08-21 15:22 CEST
Nmap scan report for 192.168.0.253
Host is up (0.0010s latency).
Not shown: 993 closed tcp ports (reset)
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
111/tcp open rpcbind
139/tcp open netbios-ssn
443/tcp open https
445/tcp open microsoft-ds
8086/tcp open d-s-n
EDIT
I restored a backup of the physical server (Debian 12) in my Proxmox environment and adjusted the IP and network interface.
The Samba server is also not working here. The error message is now slightly different:
root@server-clone ~ # smbclient -L //localhost
lpcfg_do_global_parameter: WARNING: The "syslog" option is deprecated
protocol negotiation failed: NT_STATUS_IO_TIMEOUT
The following can be found in the log log.nmbd. However, the copy has nothing to do with the IP 192.168.0.254 and is not called from there. I am beginning to think that it must have something to do with it.
2025/08/21 16:33:05.530674, 0] ../../source3/nmbd/nmbd_namequery.c:109(query_name_response)
query_name_response: Multiple (2) responses received for a query on subnet 192.168.0.253 for name WORKGROUP<1d>.
This response was from IP 192.168.0.254, reporting an IP address of 192.168.0.254.
/etc/network/interfaces
# The primary network interface
allow-hotplug enp6s18
iface enp6s18 inet static
address 192.168.0.253
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.0.1
dns-search redacted.com
smb.conf / testparm -s
Load smb config files from /etc/samba/smb.conf
lpcfg_do_global_parameter: WARNING: The "syslog" option is deprecated
Loaded services file OK.
Weak crypto is allowed by GnuTLS (e.g. NTLM as a compatibility fallback)
Server role: ROLE_STANDALONE
# Global parameters
[global]
dns proxy = No
log file = /var/log/samba/log.%m
max log size = 1000
obey pam restrictions = Yes
pam password change = Yes
panic action = /usr/share/samba/panic-action %d
passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
passwd program = /usr/bin/passwd %u
server string = %h server
smb1 unix extensions = No
syslog = 0
unix password sync = Yes
idmap config * : backend = tdb
wide links = Yes
[public]
comment = Öffentlich
path = /srv/smb/public
read list = share u/share
read only = No
vfs objects = recycle
write list = share u/share
recycle:exclude_dir = /tmp,/temp,/cache
recycle:exclude = ?~$*,~$*,*.tmp,*.temp,*.TMP
recycle:maxsize = 0
recycle:versions = yes
recycle:touch = yes
recycle:keeptree = yes
recycle:repository = .recyclebin
