Access to Samba from one of the configured VLANs is not possible or very sluggish.
You UCS server has configured multiple VLANs and clients are located in these VLANs.
Make sure your Samba knows about the additional interfaces and is configured to use it by UCR variables:
samba/interfaces/bindonly: samba/interfaces: lo <interfaces/primary> eth0.201 eth0.202 samba/register/exclude/interfaces: docker0
testparm commando presented the correct settings, too.
But Samba service itself was not listening to the configured interfaces:
root@ucs:~ # netstat -anp| grep ":389" tcp 0 0 10.250.200.100:389 0.0.0.0:* LISTEN 1926/samba: task[ld tcp 0 0 127.0.0.1:389 0.0.0.0:* LISTEN 1926/samba: task[ld tcp6 0 0 ::1:389 :::* LISTEN 1926/samba: task[ld udp 0 0 10.250.200.100:389 0.0.0.0:* 1933/samba: task[cl udp 0 0 127.0.0.1:389 0.0.0.0:* 1933/samba: task[cl udp 0 0 127.0.0.1:51341 127.0.0.1:389 VERBUNDEN 1266/nmbd udp6 0 0 ::1:389 :::* 1933/samba: task[cl
The configuration of Samba did not match the one which Samba was currently running as in the above example not additional IPs (or interfaces) are bound to the samba processes.
Restart Samba to re-initialize the configuration from the configuration file: