networking - How to see http requests made on a network?

I have an Android phone, which have an app. This app uses an API. Now, I want to know the URL of this API. I sure the mobile phone connects with the app using some HTTP requests. I also want to know what kind of HTTP requests and its parameters.

The easiest way to get that URL, I guess, is to connect my Android phone to my own private WiFi network, and then get a list of all HTTP requests made, and then pick out the one my phone is using.

So my question is: How do I see all HTTP requests made on my wifi network? Is it WireShark? And if so, how do I see the actual posts?

(Is this the right forum? It was definetely not StackOverflow and I guess this is a "network" question...)

Answer

WireShark will work, but you will have to get the requests routed to the computer running WireShark. Your WiFi router may have additional ports, but they are probably connected using an internal switch, so you won't see the WiFi traffic on those other ports.

The easiest would be if you have a Hub that you can connect between the router and your Internet source (perhaps a cable or DSL modem), then put your computer running WireShark on one of the other ports on the Hub.

If you have a computer with two ethernet ports, you may be able to route the traffic through that, and run WireShark to see the traffic.

ARP poisoning will probably also work, but is more involved. However, that is an option using just another computer on the WiFi network.

All of this assumes that you are using HTTP instead of HTTPS. With HTTPS, you won't be able to see the actual traffic contents, but should still be able to see the IP address of the destination, and might be able to see the initial DNS lookup.