Thanks for your suggestion. I don't know how to interpret this, but here it is:
root@Teltonika-TRB142:~# netstat -tupan
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Pro
gram name
tcp 0 0 0.0.0.0:4204 0.0.0.0:* LISTEN 23980/s
hellinaboxd
tcp 0 0 127.0.0.1:5037 0.0.0.0:* LISTEN 2510/ad
bd
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 2939/uh
ttpd
tcp 0 0 0.0.0.0:5555 0.0.0.0:* LISTEN 2510/ad
bd
tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 23221/d
nsmasq
tcp 0 0 192.168.2.1:53 0.0.0.0:* LISTEN 23221/d
nsmasq
tcp 0 0 100.86.177.93:53 0.0.0.0:* LISTEN 23221/d
nsmasq
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 2362/dr
opbear
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 2939/uh
ttpd
tcp 0 0 100.86.177.93:39603 222.154.29.214:1232 ESTABLISHED 4739/so
dog
tcp 0 407 192.168.2.1:4204 192.168.2.249:26187 ESTABLISHED 23980/s
hellinaboxd
tcp 0 0 100.86.177.93:39602 222.154.29.214:1232 ESTABLISHED 4739/so
dog
tcp 0 1 100.86.177.93:40007 222.154.29.214:1232 SYN_SENT 4739/so
dog
tcp 0 1 100.86.177.93:40006 222.154.29.214:1232 SYN_SENT 4739/so
dog
tcp 0 0 100.86.177.93:39600 222.154.29.214:1232 ESTABLISHED 4739/so
dog
tcp 0 210 192.168.2.1:4204 192.168.2.249:26103 ESTABLISHED 23980/s
hellinaboxd
tcp 0 0 192.168.2.1:80 192.168.2.249:26084 ESTABLISHED 2939/uh
ttpd
tcp 0 0 :::80 :::* LISTEN 2939/uh
ttpd
tcp 0 0 ::1:53 :::* LISTEN 23221/d
nsmasq
tcp 0 0 fd67:b215:b54::1:53 :::* LISTEN 23221/d
nsmasq
tcp 0 0 fe80::d09b:4dff:fec0:641e:53 :::* LISTEN 23
221/dnsmasq
tcp 0 0 fe80::728b:38ef:52ce:bcbb:53 :::* LISTEN 23
221/dnsmasq
tcp 0 0 :::22 :::* LISTEN 2362/dr
opbear
tcp 0 0 :::443 :::* LISTEN 2939/uh
ttpd
udp 0 0 100.86.177.93:59924 103.242.70.5:123 ESTABLISHED 4438/nt
pclient
udp 0 0 127.0.0.1:53 0.0.0.0:* 23221/d
nsmasq
udp 0 0 192.168.2.1:53 0.0.0.0:* 23221/d
nsmasq
udp 0 0 100.86.177.93:53 0.0.0.0:* 23221/d
nsmasq
udp 0 0 0.0.0.0:67 0.0.0.0:* 23221/d
nsmasq
udp 0 0 :::547 :::* 2692/od
hcpd
udp 0 0 ::1:53 :::* 23221/d
nsmasq
udp 0 0 fd67:b215:b54::1:53 :::* 23221/d
nsmasq
udp 0 0 fe80::d09b:4dff:fec0:641e:53 :::* 23
221/dnsmasq
udp 0 0 fe80::728b:38ef:52ce:bcbb:53 :::* 23
221/dnsmasq