Why won't my Xbox work on my router but it work through my modem

[Leenobles]

Xbox 360 problems

 

[Batem4n]

Hi, Leenobles.

What type of router do you have? Also, are you connecting to your router via wireless or Ethernet?
If you connecting wirelessly, try an Ethernet cable. If you are connecting through Ethernet, try connecting wirelessly.

Try this first and see what happens.
Hope it helps.