Using wifi router with combo cable modem/wifi router - IP address questions

[x509]

I want to use a separate wifi router with my Comcast cable modem that has a built-in wireless router. I want to improve speed and also use a better firewall.

Am I correct that if I put the Comcast cable modem into bridge mode, I can still address it via it's IP address, which for me is 192.168.1.1.

So should I set up the separate wireless router as 192.168.1.2? Will this device also get an external IP address on the Comcast WAN?

Thanks

 

[bloodypulp]

No. Most combo modem/routers will not be IP addressable in Bridge mode. The WAN[external] interface on your separate router will have the public IP address which was previously on the combo unit.
The LAN[internal] interface on your separate router will be 192.168.xxx.xxx or whatever private IP address range.
When you change the router for your internet service, notify the ISP that the router MAC address has changed.

 

[x509]

No. Most combo modem/routers will not be IP addressable in Bridge mode. The WAN[external] interface on your separate router will have the public IP address which was previously on the combo unit.
The LAN[internal] interface on your separate router will be 192.168.xxx.xxx or whatever private IP address range.
When you change the router for your internet service, notify the ISP that the router MAC address has changed.

The online help for the Comcast cable modem seems to say that even after being put into bridge mode, that device is still addressable. I had my doubts. Thank you for this confirmation.

 

[sirmonkey1985]

No. Most combo modem/routers will not be IP addressable in Bridge mode. The WAN[external] interface on your separate router will have the public IP address which was previously on the combo unit.
The LAN[internal] interface on your separate router will be 192.168.xxx.xxx or whatever private IP address range.
When you change the router for your internet service, notify the ISP that the router MAC address has changed.

you don't need to notify comcast of the mac address change since your ip is tied to your mac address. so if it changes you just get a new ip when you restart the modem.


also depending on which combo modem you have, i had the older version but i believe all their combo routers use 10.0.0.1 instead of 192.168.1.1 so you might still be able to access the router that way. but depending on which one you have you can also access the router settings remotely through your xfinity account on their website.

 

[pek]

I also have comcast, keep in mind that some comcast routers will only allow one device (unless you have business service) to have an ip address if the router is handing out ip's, the first device that it sees connect. What i did was get my own firewall, normally most brands allow you to do mac-mirroring so you can change the firewall untrust interface mac to the one that's registered on the router. I set my firewall (an older zywall usg-50) to do dhcp for my network. I also just set my wifi router to bridge mode (just don't use the "wan" interface of the router to connect to the firewall, use one of the other interfaces) so all my devices can talk to each other (all the same subnet). I could have set up the wifi router on another dmz interface on the firewall, but I never got around to it, and making up the rules to allow some devices on wifi to talk into my network was a kind of pain, I don't have a 'guest' network because I don't have guests.

 

[jardows]

Who manufactures your Comcast gateway? If it is an ARRIS product, I know that they can be accessed using 192.168.100.1 while in bridge mode. Your router/firewall may not allow it, since you are trying to access a private IP address through the WAN, so you may have to disconnect the router and connect a computer directly.

 

[x509]

Yes, my Comcast gateway is an ARRIS product. -1, no -2 to ARRIS for the worst-ever "user guide." A Netgear user guide is a wealth of information, in comparison. With the ARRIS user guide, once you connect up the cables, it's "Good luck, Charlie."