NAT Type still strict after opening

[ItsMystic]

I'm trying to connect to a server I have on one of my network devices. I've forwarded the correct port, set NAT to open, enabled/disabled UPnP, all to no avail. I cannot access said server from any outside network, regardless of which port or setting I use.

My router is directly plugged into the wall port, no other 2nd NAT that I'm aware of. The IP for the internet port begins in 172.16.x.x

[antinode · Accepted solution]

> [...] that goes to the buildings' switch. [...]

   Which goes to what?  I sure don't know.  ("building's"?  Or two
buildings, one switch?)

> [...] AFAIK there's no carrier nat, [...]

   That "172.16.x.x" is coming from something; _I_'m not doing it.

> In the case there's actually a CGN on a router upstream of mine, is
> there anything I can do to avoid it? [...]

   If it's caused by equipment which is out of your control, then you'd
need to complain to the people in whose control it is.  You can't jump
over it.  In some cases, when the ISP's responsible, you can get a real
public address by asking.  In other cases, crossing the right palm with
silver is required.

   As is often the case, blame assignment is Job One.  In this case, it
would seem to lie some place between your ISP and your wall port, but
who's responsible for what in that chain is (like so many things) beyond
my ken.

[antinode]

> My router is directly plugged into the wall port, [...]

   Swell.  I, for one, don't know what's behind that wall.  Do you?

   Normally, I'd direct you to the usual problems with port forwarding:

      https://community.netgear.com/t5/x/x/m-p/1859106

But you seem to have included all the required information, already.

> [...] no other 2nd NAT that I'm aware of. [...]

   You just don't recognize it.

> [...] The IP [address] for the internet port begins in 172.16.x.x

   Plug that address into the form at: https://whois.arin.net/ , and get
the bad news.  One possibility:

      https://en.wikipedia.org/wiki/Carrier-grade_NAT

But other things (routers) behind that wall could produce the same
effect.

[ItsMystic]

The wall port is patched to a cat6 cable, and that goes to the buildings' switch. AFAIK there's no carrier nat, I called my ISP earlier today and the rep insisted that they don't have a CGN and I'd have to do my NAT configuration thru my own router. He sounded snarky though, so I doubt he put any actual effort into getting the right information lol

In the case there's actually a CGN on a router upstream of mine, is there anything I can do to avoid it? Using a vpn isn't exactly a feasable option for me.

[antinode · Accepted solution]

> [...] that goes to the buildings' switch. [...]

   Which goes to what?  I sure don't know.  ("building's"?  Or two
buildings, one switch?)

> [...] AFAIK there's no carrier nat, [...]

   That "172.16.x.x" is coming from something; _I_'m not doing it.

> In the case there's actually a CGN on a router upstream of mine, is
> there anything I can do to avoid it? [...]

   If it's caused by equipment which is out of your control, then you'd
need to complain to the people in whose control it is.  You can't jump
over it.  In some cases, when the ISP's responsible, you can get a real
public address by asking.  In other cases, crossing the right palm with
silver is required.

   As is often the case, blame assignment is Job One.  In this case, it
would seem to lie some place between your ISP and your wall port, but
who's responsible for what in that chain is (like so many things) beyond
my ken.

[ItsMystic]

Just one building. There are two switches trunked together (I believe) to cover the 48 wall outlets in the building. If I remember correctly that is. One of the switches may turn out to be a router. Oh well, case closed though, nothing on my end. Thanks for your help