Question: what is triggering port 5678 via UDP ?

Hello,

may i know is there any active app on virtualmin server which trigger port 5678 via UDP ?

the reason i ask is my firewall log is showing IP 10.10.120.1 and 0.0.0.0 are trying to open the port:

Apr 26 14:33:47 customer kernel: Firewall: *UDP_IN Blocked* IN=em1 OUT= MAC=ff:ff:ff:ff:ff:ff:00:0c:29:6f:46:ba:08:00 SRC=10.10.120.1 DST=255.255.255.255 LEN=125 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=UDP SPT=35685 DPT=5678 LEN=105 Apr 26 14:33:47 customer kernel: Firewall: *UDP_IN Blocked* IN=em1 OUT= MAC=ff:ff:ff:ff:ff:ff:00:0c:29:f6:38:32:08:00 SRC=0.0.0.0 DST=255.255.255.255 LEN=125 TOS=0x00 PREC=0x00 TTL=64 ID=0 PROTO=UDP SPT=5678 DPT=5678 LEN=105 Apr 26 14:33:47 customer kernel: Firewall: *UDP_IN Blocked* IN=em1 OUT= MAC=ff:ff:ff:ff:ff:ff:00:0c:29:f6:38:3c:08:00 SRC=0.0.0.0 DST=255.255.255.255 LEN=125 TOS=0x00 PREC=0x00 TTL=64 ID=0 PROTO=UDP SPT=5678 DPT=5678 LEN=105

That will most probably be a MikroTik device in the network sending out “neighbour discovery” packets to look for other MikroTik devices.
Depending on you network setup (where is this server located?) this could be from your ISPs’ network, I suppose.

Best regards,
Christian