Problem switching from AT&T to Cox

  • I've been using my Amplifi HD with AT&T Uverse service for a few years and everything worked smooth as silk from day one. However, I decided to switch over to Cox to get Gigablast. I really wish there was reasonably priced fiber here in South Orange County. Now, I'm having difficulty getting my router to sync up with the Cox modem.

    The first thing I did once I connected the Cox modem to the wall jack, was to test internet and modem connectivity directly to a single laptop. Everything went well without making any setting changes to the laptop. I can connect to the modem config page and out to the internet.

    My AT&T setup was configured on my Aplifi HD router using DHCP with the Gateway address of the AT&T router/modem. I kept the DHCP setting and just moved my WAN cable from the AT&T router to the Cox modem, but the Amplifi router doesn't auto detect the new modem and it's relevant settings. It displays a No Internet Connection message on the display. Strangely, even though the only thing I have changed is the Internet Gateway, it seems to have affected the WiFi settings because I am then unable to connect to the router via the AmpliFi app on my Android phone that is connected locally to the same WiFi network. Eventually, I was able to connect to the AmpliFi via the web config page. I tried switching to Bridge mode, but that didn't seem to help either.

    I chatted with Cox support and their response was simply, plug it in to your router and it should work. The level 1 tech (I assume) could not provide any remotely technical info. Perhaps if I were starting with a factory fresh router, it would be that simple, but it's not that way for me now.

    One other note just in case it would suggest a specific approach in this new configuration. I am planning to run a Plex server over this connection and want to be able to establish direct connections with my family to watch movies from my collection. I did have to deal with a Double NAT situation on my AT&T setup due to conflicting local IP addresses by setting up a pinhole to direct a specific port to my Amplifi router and than to my Plex server.

    I'm actually pretty tech savvy, but I don't tinker with network settings very often, so it is very likely that I'm forgetting to do something here. I really thought this was gonna be a slam dunk once I had internet connectivity from my laptop, now I am tempted to do a factory reset of the AHD router and start from scratch. If I go that route, is there a way I can save some of the WiFi info that I have setup like customized Device names, icons, etc?

    Thanks in advance,


  • I decided to go ahead and factory reset the router and everything came up fine. It's a shame there isn't a more elegant way to tell the router to detect settings from a new gateway.

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