Hello.
Has anybody ever set up the Flint 2 router with an Xfinity cable modem?
Needing to know if Xfinity’s cable modem are double NAT or CGNAT.
Xfinity usually give you a public ip. It’s not behind a CGNAT.
Seeing some comments on your post about Wireguard VPN but you never explicitly said you wanted that. Are you just trying to replace your Xfinity router?
And yeah Xfinity doesn’t use CGNAT. Not from what I’ve seen anyway through both personal experience and setting up others’.
Setup dozens. Xfinity does not use CGNAT. After you connect your Flint2 to one of the LAN ports, you will have to use the Xfinity app to login to your modem and setup a port forward for 51820 UDP (for wireguard) to your Flint2.
Thanks.
So do I simply hook up the Flint 2 and that’s it?
Thanks. That is good to know.
I am not looking to replace my Xfinity router. What I’m looking to do is set up a Flint 2 router here that I can connect my Beryl travel router to when I am abroad.
PS - Comcast’s download speeds are great, but the upload is typically capped at 40 or 50 even on the highest plans, so that will limit your VPN speeds when connecting from outside your home.
I’d recommend putting the XFINITY gateway, as they like to call it, in bridge mode
Ok, so you are looking to host a VPN server. Just a heads up, these devices are routers and they aren’t always used as VPNs. So it’s best not to assume we know what you’re trying to do 
With that said, I recommend reading through this and the resources that are linked in it: Digital Nomad VPN Tutorial using Wireguard or Tailscale
Ok.
What I’m looking to do is set up a Flint 2 router here that I can connect my Beryl travel router to when I am abroad.
On that upload being capped, is that specifically for Xfinity routers?
Ok. Gonna have to figure out how to do that.
What I’m looking to do is set up a Flint 2 router here that I can connect my Beryl travel router to when I am abroad.
Understood. Sorry about that.
I will definitely read what you linked today. Definitely appreciate that.
It’s typical of any CATV provider. The DOCSIS protocol is very asymmetrical. If you can find a fiber optic ISP in your area they’ll usually provide equal download/upload.
50mbps is actually plenty for working remotely though. A work laptop doing email, voip and video calls rarely uses more than 20mbps.
No worries! That should answer all your questions between the written content and the linked GL.iNet Docs. If you need more help, give the subreddit a search. Port forwarding is quite easy to setup, especially on Xfinity because of the mobile app which makes it possible to complete in 10 seconds.
Good deal. I appreciate that.
Good deal. Much appreciated.
In the equipment portion, it says the Brume 2 is recommended. I have the Flint 2, so I’ll have to get the Brume 2 ordered today.
Thanks again.
No, your Flint 2 is perfectly fine. In fact it’s better (supports faster Wireguard speeds).
The Brume 2 is only recommended because it’s the most cost effective option (no Wi-Fi), and also comes in an aluminum casing which helps heat.