5 ms·
Doesn't it help if two people are sitting right next to each other behind the same NAT?
by cbhl 11y ago
Doesn't it help if two people are sitting right next to each other behind the same NAT?
- makomk 11y agoIt's necessary if the NAT device doesn't support hairpinning. Unfortunately, historically many didn't, so users couldn't connect to other users on the same NAT using their public IPs, even with techniques that worked fine for connecting to other identical NAT setups elsewhere.
- MichaelGG 11y agoIs it necessary? You could do a broadcast on the LAN if the public IP is the same.
- nitrogen 11y agoThat same-subnet local IPs behind one public IP can reach each other is probably not a safe assumption to make.
- MichaelGG 11y agoYou only send a broadcast to attempt to reach the other party. If it does not work, you fallback to the public IP. This is sorta what ICE does already.
- profmonocle 11y agoIt's not safe to assume that multiple clients behind the same public IP are on the same LAN. At my office, wired and wireless clients NAT to the same public IP, despite being on different subnets. Plus, thanks to IPv4 depletion there might be multiple layers of NAT involved, because ISPs are having to deploy carrier-grade NAT.