ADSL Home Hub NAT Sessions

ADSL Home Hub NAT Sessions

During Covid working from home I can poll my Home hub to check out the NAT sessions.

We wanted t see what connections a Mobile Phone app made during the call.

Looking at NAT Sessions using a Raspberry Pi

I want to see what nodes my Smartphone App connects to.

I do not know how to log onto the Smartphone or the nodes.

I can use the NAT table to see what connections are set up and ripped down.

The new home hub I have does not offer this.

The Raspberry Pi foundation have a really good web page about setting up a Wireless Access point.

I can plug this into any Hub and I can log onto this WAP.

https://www.raspberrypi.org/documentation/configuration/wireless/access-point-routed.md

The diagram below is copied from the Raspberry Pi web page. My IP addresses are 192.168.1.x instead of 10.10.0.x :-

                                          +- RPi -------+
                                      +---+ 10.10.0.2   |          +- Laptop ----+
                                      |   |     WLAN AP +-)))  (((-+ WLAN Client |
                                      |   | 192.168.4.1 |          | 192.168.4.2 |
                                      |   +-------------+          +-------------+
                  +- Router ----+     |
                  | Firewall    |     |   +- PC#2 ------+
 (Internet)---WAN-+ DHCP server +-LAN-+---+ 10.10.0.3   |
                  |   10.10.0.1 |     |   +-------------+
                  +-------------+     |
                                      |   +- PC#1 ------+
                                      +---+ 10.10.0.4   |
                                          +-------------+

I added netstat-nat and iptstate to the Raspberry Pi to list the NAT connections.

https://www.cyberciti.biz/faq/display-iptables-router-nat-connections-using-netstat-nat/

https://tweegy.nl/projects/netstat-nat/

iptstate in real time:- https://www.phildev.net/iptstate/

I tried Wireshark but it was very confusing. There seemed to be a very large number of IP addresses being used.

I built this on a microSD for a Raspberry Pi 3 and on a fresh install of Raspberry Pi Desktop. https://www.raspberrypi.org/software/raspberry-pi-desktop/

I can use this to filter the connections I am interested in:

 date && sudo netstat-nat  -n | grep "62.239"