Equipment (Modems,Gateways)
Modems, Gateways, and Networking Devices
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pfSence Behind an CBR-T Gateway and One Static WAN IP

I have used pfSence with Comcast Internet in the past with my own modem. However, it has always been with a DHCP WAN. I now have Comcast Buisness with an CBR-T (CGA4131COM) Gateway/Router and one Static WAN IP.


I have my assigned Static WAN IP as well as my WAN Subnet. My understanding is that within the pfSence WAN interface. I need to  change from DHCP to Static and input my Static IP into the WAN IP field. Then input my Static WAN IP Subnet into the Subnet field.


Next I believe I would have to call Comcast Business Support to have them put the CBR-T into a kind of Bridge mode. Is this it? Is there anything I'm missing to get the pfSence device connected?


Also, am I able to keep the stock LAN IP across both devices.

e.g.  CBR-T ( -> pfSence ( -> LAN PC (10.1.10.xx)

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Official Employee

Re: pfSence Behind an CBR-T Gateway and One Static WAN IP

If you're using a third-party device to delegate your internal network and, your firewall is configured with the usable Static IP address you can utilize the 10.1.10. X scheme from your firewall. You will want to disable the DHCP on the Comcast Business Modem. This is what we call a Virtual Bridge. You can do this by signing in to your Comcast Business modem using the address and the default username and password. If you wish to continue using the same DHCP on both devices, as long as the firewall handing out the 10.1.10. X LAN address is provisioned with the usable address, you should not run into any issues. It is best to utilize one DHCP server per network (or multiple ones working in a redundant configuration).  If you still need assistance, please send me a private message.

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