Comment on Chaining routers and GUA IPv6 addresses
2xsaiko@discuss.tchncs.de 2 weeks ago
Not a professional networking guy either but here’s my opinion.
What I would do is use the ISP router as is, open all ports on it (except to itself, hopefully it doesn’t do that…), and put a firewall in between the router and everything else that controls the actual access to everything behind it (in bridge mode between the two network interfaces of the firewall, so you only have the one network).
Could a potential second router also assign addresses to devices in that globally routable space directly?
Devices in IPv6 assign addresses themselves via SLAAC, you just need one device advertising the prefix which the ISP router should already do. The firewall should be able to just purely be there for packet filtering. If you need fixed addresses for public facing servers I would just assign them manually to the respective boxes as you likely also need to add them to public DNS manually anyway.
robber@lemmy.ml 2 weeks ago
Thank you! Do you have an example for such a firewall device? Could something like the TP-Link Archer AX55 in IPv6 “pass-through” mode do the job? Or would you go for a standalone firewall? My budget is around a hundret bucks.
maxwellfire@lemmy.world 2 weeks ago
I’d recommend something that you can put openwrt or opnsense/pfsense on. I think the tplink archers support openwrt at least.
The ISP router opening things at a port level instead of a host level is kinda insane. Do they only support port forwarding? Or when you open a port range can you actually send packets from the WAN to any LAN address at that port.
Can you just buy your own modem, and then also use your own router? (If the reason you need the ISP router is that it also acts as a modem).
Does the ISP router also provide your WiFi? If it does you should definitely go with a second router/access point and then disable the one on the ISP router.
robber@lemmy.ml 2 weeks ago
And openwrt is capable enough?
Yeah it’s insane right? Every address is reachable when I open a port range. And it’s like there are ~ 10 predefined services (HTTP/S, SMTP, …) and the category “All other ports” where also 22 is part of. So I really have the choice to either keep everything shut or leave everything wide open.
I think I can’t use my own modem but I’ll have to double check with my ISP. But yes the Wi-Fi is also provided by that router and it’s also quite crappy.
maxwellfire@lemmy.world 2 weeks ago
Yeah openwrt should be great. It uses nftables as a firewall on a Linux distribution. You can configure it through a pretty nice ui, but you also have ssh access to configure everything directly if you want.
The challenge is going to be what the ISP router supports. If it supports bridge mode then things are easy. You just put your router downstream of it and pretend like it’s a modem. Then you configure openwrt like it’s the only router in the network.
If you don’t have bridge mode then things are harder. There’s some helpful information here forum.openwrt.org/t/…/19 even though the situation is slightly different since they also don’t want a firewall. But you probably need to configure your upstream side on the openwrt router similarly.
2xsaiko@discuss.tchncs.de 2 weeks ago
Most computers with (at least) two network interfaces will do. If it’s something too crappy your throughput will be limited by CPU speed but I can’t tell you exact recommendations here. Here’s OPNsense’s hardware recommendations for example, they’re not high at all. Off-the-shelf devices that allow you to do this should probably be fine too.
I’d put Linux on it and use nftables but BSD PF seems to be very popular for firewalls (OPNsense/pfSense are built on this) which I have never used so consider that too.
robber@lemmy.ml 2 weeks ago
Thank you! I’ll evaluate and report back.