Unable to port forward Linksys E1000 router after new Arris modem was installed.

[ButterMyToes]

So, here's my problem. I'm trying to start up a Minecraft server for a few friends and I, which I have done before. I used to have no problem doing this, until the modem was changed to an Arris modem. I'm almost 100% sure it is the modem, considering the problem only started happening after it was installed. If more information is needed, ask away. Thank you very much!

 

[Emerald]

Usually an Arris modem has a build in router; therefore, you will have to either port forward to the WAN IP of the Linksys in the Arris modem, or set the Arris modem in to bridge mode (modem only), or enter the WAN IP of the Linksys in to the DMZ on the Arris modem.