Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    CenturyLink BRAS LAN Subnetting w/ Static IP

    Scheduled Pinned Locked Moved Routing and Multi WAN
    6 Posts 3 Posters 764 Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • T
      techsalot
      last edited by

      I’m not sure where this post should go so I’ll start here.

      Physical: Fiber > ONT > Ethernet > pfsense WAN

      I have a fiber connection that uses CenturyLink CBRAS aka BRAS. I have been using DHCP and Eero but want to change things up a bit. I got a static IP and attempted to use it. The tech says I am required to use the CL “modem” and configure “LAN Subnetting” on it.

      I want to do this without the CL HW if possible.

      I have already configured pfsense to get the DHCP address from CL and that works as I am online, but where do I configure the static IP? Here are the details I was given for ref.

      Static IP
      Network Address 71.33.xxx.72/30
      Router/Client 71.33.xxx.73
      Gateway 71.33.xxx.74
      Broadcast 71.33.xxx.75
      DNS 1 205.171.3.26
      DNS 2 205.171.2.26
      Wildcard 0.0.0.3

      1 Reply Last reply Reply Quote 0
      • Z
        ZPrime
        last edited by

        You need to clarify with CLink how they want this done.
        With many providers, when you want a static IP, they require their own equipment to be in the path, and you then get a static IP behind it.

        If that's the case, their "BRAS" box would actually be 71.33.xx.74 (the "gateway"), and you'd set your pfSense WAN to use 71.33.xxx.73/30 (with a static default GW of .74). In this sort of situation, you'd probably want to change your "monitor IP" to something other than the gateway, because there's little point to monitoring a device that's just on the other end of your own c5e/c6 cable and on the same power as your router.

        This sort of thing is more common with the Telcos IME, but I've seen it with Comcast Enterprise (cable) as well. When you ask for a static, they take their coax modem/router device out of bridge mode and turn it into a router with a /30 facing you. If you request more IPs, they then just route a larger block to you over that /30 (so your router would get one side of the /30, and then they might issue a /29 or /28 with a bunch more IPs you can use on the "inside" of your own router).

        1 Reply Last reply Reply Quote 0
        • stephenw10S
          stephenw10 Netgate Administrator
          last edited by

          They route the /30 to you via a dhcp address.

          You may be able to use the complete /30 as VIPs. Almost certainly both .73 and .74 but .72 and .75 might be available.

          Add them as IPAliases and test.

          Steve

          1 Reply Last reply Reply Quote 0
          • T
            techsalot
            last edited by

            BTW..... This what their setup looks like: https://www.centurylink.com/home/help/internet/modems-and-routers/advanced-setup/cbras-setup.html

            1 Reply Last reply Reply Quote 0
            • T
              techsalot
              last edited by

              @techsalot said in CenturyLink BRAS LAN Subnetting w/ Static IP:

              BTW..... This what their setup looks like: https://www.centurylink.com/home/help/internet/modems-and-routers/advanced-setup/cbras-setup.html

              Someone else mentioned this: https://docs.netgate.com/pfsense/en/latest/book/routing/routing-public-ip-addresses.html

              I'll give it a try.

              T 1 Reply Last reply Reply Quote 0
              • T
                techsalot @techsalot
                last edited by

                @techsalot Didn't work

                1 Reply Last reply Reply Quote 0
                • First post
                  Last post
                Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.