With your guidance I am experimenting with pfsense and ntopng. Today I saw a strange ip address 172.30.10.xx which was not part of my network.
ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.77 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::9b56:83b:a6d4:830 prefixlen 64 scopeid 0x20
ether 00:50:56:b2:ca:67 txqueuelen 1000 (Ethernet)
RX packets 37837 bytes 7257793 (7.2 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 21081 bytes 1583997 (1.5 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Further when I ping there is a reply, so I run nmap to see what else is there and I got this
abhay@pop-os:~$ nmap -sn 172.30.10.0/24
Starting Nmap 7.80 ( https://nmap.org ) at 2020-01-04 21:09 IST
Nmap scan report for 172.30.10.8
Host is up (0.0036s latency).
Nmap scan report for 172.30.10.11
Host is up (0.0038s latency).
Nmap scan report for 172.30.10.13
Host is up (0.067s latency).
Nmap scan report for 172.30.10.15
Host is up (0.0032s latency).
Nmap done: 256 IP addresses (4 hosts up) scanned in 7.21 seconds
and when I run traceroute I got this
On traceroute of 172.30.10.13 it shows my ISP gateway. When I disconnect my WAN I cannot ping those ipaddress. I dont know whats happening and how to I stop this, Please help.
note: I could only upload 1 image so had to cut and paste earlier one.