Redirect port 80 to 8080 and make it work on local machine

Question

I redirected traffic for port 80 to 8080 on my machine with

sudo iptables -A PREROUTING -t nat -p tcp --dport 80 -j REDIRECT --to-ports 8080

It works fine for all the world except my own machine. I am a developer and I need to redirect port 80 to 8080 for myself.

My IP is 192.168.0.111

My web server runs on port 8080

I wish to open website from http://192.168.0.111/ instead of http://192.168.0.111:8080/ from same machine where server runs.

Solution 1

You need to use the OUTPUT chain as the packets meant for the loopback interface do not pass via the PREROUTING chain. The following should work; run as root:

iptables -t nat -A OUTPUT -o lo -p tcp --dport 80 -j REDIRECT --to-port 8080

Solution 2

Simple just use iptables allowing both port 80 and 8080 then redirect 80 to 8080 make sure you are assigning to the correct nic.. in example I use eth0

iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 8080 -j ACCEPT
iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080

Solution 3

This worked for me.

$ sudo iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080

Solution 4

Instead of the iptables, You could try: sudo ssh -gL 80:127.0.0.1:8080 localhost

View more solutions

Comments

[ma11hew28]

Excuse me for the abberation, but what is the purpose of forwarding port 80 to 8080?

[Christian]

@mattdipasquale, normal users can't access port 80 so you couldn't run a web service like python flask as a normal user.

[David Foerster]

Why don't you just bind the web server to port 80?

[Pavel K.]

i'd guess its because non-root user cannot bind to ports 80/443 and he doesnt want to run his web service as root..

[Max]

That is an option but it is not exactly what I want because I already have web server on port 80. I will prefer to do it with iptables and keep web server on port 80 running. I guess I just have to apply rule to different step instead of PREROUTING

[cgseller]

Yes - this will cause a port conflict if you have something listening that you are port forwarding to as Max suggested. The above answer is the more general case.

[alper]

Does port 80 required to be gloabally accesible? I tried your solution, my port number 8080 is accessible but 80 is not hence it did not worked. @heemayl

[diyoda_]

This did not work, not sure why this is voted up

[heemayl]

@Diyoda_ Please define did not work.

[Jerry U]

@Alper I think you didn't read the OPs question.

[Ahmed Hamdy]

I can confirm that this doesn't work on ubuntu 18.04

[Christopher Bradshaw]

Didn't work for me on Ubuntu 18.10

[Vladimir Ishenko]

Thanks! It's working on Ubuntu 19

[Vladimir Ishenko]

After would be nice to save iptable changes sudo apt-get install iptables-persistent

[hanshenrik]

+1 works for me on Ubuntu 18.04 (at least for TCP), did port 7000->7001 and servers listening on port 7001 received incoming connections from port 7000 :)

[hanshenrik]

make sure to use the correct network interface tho, it isn't called eth0 on all systems

[mitchus]

I get a "Connection refused" when attempting this solution.

[M. Volf]

how to stop this forwarding? EDIT - FOUND IT: replace -A with -D in that command

[user3757405]

@mitchus it sounds like you don't have an SSH service. Try sudo apt install openssh-server.

[Nisharg Shah]

works perfectly in 20.04

[Sunding Wei]

not working on ubuntu 20.04 LTS

[Sunding Wei]

Works for me on ubuntu 20.04 LTS

[Dimitar II]

Probably we should first enable the port forwarding: sysctl net.ipv4.ip_forward=1 (or sysctl net.ipv6.conf.all.forwarding=1). Then make the change persistent, by uncommenting these lines in '/etc/sysctl.conf'.