Access Motorola Cable Modem through ASA 5505

Timothy Garay · ‎10-17-2016

I've seen some posts on this but the setup has always been a little different than mine.

I have TimeWarner Cable Internet with a Motorola Cable Modem connected to 0/1 of my ASA 5505 (9.1(6)) with ASDM 7.4(3) as the outside interface. To my knowledge the modem is in bridge mode but has Wi-Fi and I am able to ping the modem address (192.168.0.1) from my ASA. The outside interface of my ASA gets my public IP address from the ISP/modem.

Is there a way I can configure the ASA to allow me to access the Cable Modem (192.168.0.1) from the inside LAN? I can ping the address from the ASA. I can access the Cable Modem web GUI using it's Wi-Fi but I would like to be able to access it from my hard-wired PC and possibly some monitoring software.

I am basically familiar with Cisco CLI and the ASDM but [obviously] not with special configurations.

Any help would be greatly appreciated.

Thanks!

-TimG

Aundre Dudley · ‎10-17-2016

Hello Timothy,

If you are able to ping the cable modem's IP 192.168.0.1 from the ASA's outside interface, then the most likely culprit is NAT or routing. First ensure that your internal network has a default route that leads out through the ASA. You should remove the below NAT statement from the ASA as it appears to be misconfigured. Your ACLs and inspection rules look to allow this traffic so I would focus on routing and NAT. Also, verify that you are able to ping the cable modem's IP address from the outside interface.

ping outside 192.168.0.1

object network obj_any-01
 nat (inside,outside) dynamic obj-0.0.0.0

Timothy Garay · ‎10-24-2016

Thank you Aundre, I will give it a look next chance I have.

Currently I've swapped out my 5505 with and old router to troubleshoot other issue I've been experiencing with it so at the moment I don't have it hooked up to play around with it.

I will report back when I get more information. I do know that when I did a traceroute before, it was going out the Internet connection so I don't think the 5505 knows that the 192.168.0.1 address is actually local to it.

-TimG