How to redirect traffic from one interface to another?

Question

linux

Hello. Faced the following problem.
There is nginx on the machine, the site is hosted on it.
On the local grid, I can access my site on ip - 172.16.8.170 from ip - 172.16.8.191 (another machine on the LAN).
But from the outside world I can’t by ip - 217.149.177.16.

$ ifconfig
enp1s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.16.8.170  netmask 255.255.0.0  broadcast 172.16.255.255
        inet6 fe80::c288:74b0:fad4:d907  prefixlen 64  scopeid 0x20<link>
        ether 44:8a:5b:8e:c7:35  txqueuelen 1000  (Ethernet)
        RX packets 15304850  bytes 19034375292 (19.0 GB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9759984  bytes 924136878 (924.1 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Локальная петля (Loopback))
        RX packets 121893  bytes 16842812 (16.8 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 121893  bytes 16842812 (16.8 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1400
        inet 217.149.177.16  netmask 255.255.255.255  destination 10.111.111.1
        ppp  txqueuelen 3  (Протокол PPP (Point-to-Point Protocol))
        RX packets 13931448  bytes 18720267169 (18.7 GB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 8841915  bytes 602120766 (602.1 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

I have been looking for an answer to this question on the Internet for 4 days. Basically they write that everything is solved through iptables, but no matter what manipulations I did, it refuses to work.

Answer 1

In general, the problem was that the provider can block "standard" ports (such as 22, 80 ... ). As a result, the solution to the problem was to change the "standard" port.

Answer 2

If you have a white IP, then add to the nginx listen config with the desired IP:PORT and that's it, no redirects are needed