On Fri, May 20, 2016 at 12:19 PM, WebDawg <[email protected]> wrote: > On Fri, May 20, 2016 at 11:06 AM, Moshe Katz <[email protected]> wrote: > > > If you have static IPs from Comcast, you cannot put the device in bridge > > mode. The way that Comcast static IPs work is that your Comcast device > > advertises itself to the rest of Comcast's network as the route to your > > static addresses. In effect, just pretend that this Comcast device is in > > Comcast's central office and that you can't change anything about it. > > > > Moshe > > > > Wow. > > No wonder there are issues. I have only seen a few good modems as of late > from any cable provider. > > Are there people having the same issues with the newer Arris Cable Modem? > I see the responses in the thread, will they issue static ip addresses with > just modems/Arris? > > Really, they will not let you bring your own device with a compatable Arris > modem? > > I hate the all in one devices that they give out. I had issues with one > until I put it into bridge mode. It would not NAT correctly. > > At another location, I demanded a modem. I was paying for their fastest > internet 100M down at the time and there was no way I was going to add all > that overhead to the connection and depend on garbage firmware. > > They will not let you bring your own modem if you have a static IP.
I wrote the last message on my tablet, so I had to keep it short, but I can explain further now. Basically, when you get static IPs from Comcast, they do not want to set up the routing for them upstream in the central office (like most other ISPs would do). Instead, they assign your "Business IP Gateway" device (which is a modem/router/firewall combination) a dynamic IP that is in the same block of IPs that the entire rest of your neighborhood has. After the Business IP Gateway has received its dynamic address, it advertises itself (I believe using RIP) as the next hop to the IP addresses that have been allocated to you. Additionally, the Gateway runs a DHCP server in the 10.x.x.x range. Any computer on your network that requests an address on DHCP will receive a private address from the Gateway and the Gateway will perform NAT. In effect, this allows you to have your public addresses and private addresses on a single connection to the Internet, with the public addresses routed and the private addresses NAT'ed. To make a long story short, not only will Comcast not allow you to use a simple Arris Surfboard modem for static IPs, the way their system is set up would not even work if you tried to use a plain modem, because your modem wouldn't be able to claim the addresses. In theory, Comcast could just allow you to set up your own RIP advertisements from your own hardware. I'm guessing that the reason they don't want to do that is because they'd rather have full control. Moshe -- Moshe Katz -- [email protected] -- +1(301)867-3732 _______________________________________________ pfSense mailing list https://lists.pfsense.org/mailman/listinfo/list Support the project with Gold! https://pfsense.org/gold
