Sonic wall Install

[Shawn Sullivan]

Hey guys,

I am trying to install a sonicwall tz105 behind a basic comcast modem. The modem is not the smc business gateway. Its the model that goes into most home consumer enviroments. From what I understand it cannot be put into full bridge mode(only virtual bridge mode), And from what I have been told I need to have the comcast modem in full bridge mode.
Now that being said, one of my offices already has a sonicwall tz100 behind the same type of comcast router that is not in any form of bridge mode that I can see and it also does not have DMZ enabled and set up. Yet this offices network is fully functional with the sonicwall in full command.

I cannot figure out why I cannot get the first office I mentioned (with the tz105) to get internet.

Please help. I can supply more information.
I am brand new to IT and just learning the field, So any patience given is much appreciated.

Thanks

 

[jeff-j]

I had almost the same type problem with ATT, their u-verse routers could no longer be put into bridge mode. I had the ATT Tech, his manager plus 2 people on the phone trying to figure it out. In the end the only solution was to put the firewall in the DMZ and assign an static IP to the firewall.

 

[Shawn Sullivan]

I had almost the same type problem with ATT, their u-verse routers could no longer be put into bridge mode. I had the ATT Tech, his manager plus 2 people on the phone trying to figure it out. In the end the only solution was to put the firewall in the DMZ and assign an static IP to the firewall.

I thought I had enabled the DMZ. It is most likely I did that improperly. Any chance you could walk me through that?