Detecting Network nodes w/ Cain

Big picture:

3 PCs(A, B, C)
All connected via DLink Wireless Router
A is running a server (java process). Tank Simulation Module
B is running a client (java process). Tank AI.
C is running Cain.

Ultimate goal: Communication between A nd B needs to be modified. I would like to have control over what is sent to the server(A) from B. This could include MITH attack with APR.The data is XML. I'm decent on the Java side so I could write a parser which would handle the modification of the data from B to the server during the MITM attack.

Current problem:

Installed Cain on PC C. Clicked on "Sniffer" tab. Clicked on "Add to List". Clicked OK on the "Add MAC Address" window. Used defaults(192.168.0.1 is my routers IP), and nothing is found. I connect to the Router(via browser) and notice PC C(192.168.0.101) and PC A(192.168.0.102) in the Routers "Client List"(PC B is getting a fresh OS install as I type). Point is, I would think Cain should pick up the router and PC A.

Any help would truly be appreciated.

Cain can be 5 kinds of flaky on wireless, depending on what card/chipset you are using. If you want to modify the content, you may want to look into using Ettercap filters instead.

Thanks for the direction.

I've installed ettercap and seem to have the same problem of not being able to detect any hosts while performing a scan of the subnet. My non-educated guess is either the network card capabilities or an ettercap configuration issue. I can ping both the wireless router and PC A. Thoughts?

BTW, the filter is exactly what I was looking for.

Update: When I physically connect to the wireless router I can see the other nodes on the subnet. Seems to be specifically connecting via wireless.

I never had a problem with that when I was on wireless. As long as they are on the same subnet it should be able to see it fine. I would try installing/reinstalling the newest copy of winpcap since that is the library that is used for both of those programs I believe.

I had this exact issue and discovered that the wireless interface needed to be set within cain to not run in promiscious mode under the part where you select the interface to run on. It can be disabled by unchecking the box.
Give that a shot, it was instant for me (worked straight away after disabling it). Hope this is what you were looking for.

I guess it depends on your card then. I just had a cheap linksys usb b card. It supported promiscuous mode I guess.