4 ms·
Essentially, most NATs are symmetric, with some port forwarding rules, which operate in Full Cone mode. More interesting questions are "what happens when there
by richardwhiuk 3y ago
Essentially, most NATs are symmetric, with some port forwarding rules, which operate in Full Cone mode.
More interesting questions are "what happens when there's multiple NAT IPs?" "how long do the symmetric rules stay around for?" "what keeps them around?"
- lxgr 3y agoAt least most home routers (on connections that still get a public IPv4 address) are fortunately not symmetric, or STUN would not be working with them. (STUN only works if at least one endpoint is port-restricted or better, if I remember correctly; it might also have been both ends.) Many carrier-side NATs are indeed often symmetric, unfortunately.