I have a raspberry pi 3 and I'm currently using it as a internet hotspot: I use a ethernet cable to get the connection, and the WiFi card to share it. (Eth0 --> Wlan0). The only problem with this is that I can't do any port forwarding with the devices connected to it... I have searched for many hours with no successful results, I tried 'iptables' (which i'm not familiar with...) with still no success...
So here are some infos that might help: (ifconfig on the raspberry pi)
pi@raspberrypi:~ $ ifconfig
eth0 Link encap:Ethernet HWaddr b8:27:eb:1b:c6:ec
inet addr:192.168.0.37 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: 2a01:e35:2f32:7120:ba27:ebff:fe1b:c6ec/64 Scope:Global
inet6 addr: fe80::ba27:ebff:fe1b:c6ec/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:789 errors:0 dropped:1 overruns:0 frame:0
TX packets:344 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:73638 (71.9 KiB) TX bytes:43983 (42.9 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:180 errors:0 dropped:0 overruns:0 frame:0
TX packets:180 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:12958 (12.6 KiB) TX bytes:12958 (12.6 KiB)
wlan0 Link encap:Ethernet HWaddr b8:27:eb:4e:93:b9
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:13 errors:0 dropped:13 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2775 (2.7 KiB) TX bytes:0 (0.0 B)
And 'ifconfig' on my PC:
nuf@nufPC ~ $ ifconfig
enp4s0f2 Link encap:Ethernet HWaddr 74:d0:2b:ba:93:db
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:1552790 errors:0 dropped:0 overruns:0 frame:0
TX packets:880671 errors:0 dropped:7 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1836089487 (1.8 GB) TX bytes:99384524 (99.3 MB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:1279658 errors:0 dropped:0 overruns:0 frame:0
TX packets:1279658 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:88890909 (88.8 MB) TX bytes:88890909 (88.8 MB)
wlp3s0 Link encap:Ethernet HWaddr 24:fd:52:3c:f6:ee
inet addr:10.0.0.17 Bcast:10.0.0.255 Mask:255.255.255.0
inet6 addr: fe80::675:363e:5f61:f10c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:71245 errors:0 dropped:0 overruns:0 frame:0
TX packets:49945 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:76745606 (76.7 MB) TX bytes:7135427 (7.1 MB)
So for exemple I would like to create a server which use the port 1337 I can't directly forward it to my box, I need to forward it to my Raspberry which forward it to my box I guess... I hope you can help me :)