How to do port forwarding with iptables?

Question

linux

Hello everyone
. I know that the topic is hackneyed and there are a lot of such questions on the Internet (because I myself rummaged and checked everything in practice), but the problem still remains:
you need to make an elementary forwarding of incoming traffic from port 80 to port 8080. iptables is clean . that is, they are generally clean, nothing is written in any plate / chain ...
I do it like this:

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

nothing on port 80. nginx hangs on port 8080, which gives the nginx page
when a request is made to host ip: 80 from another machine, a connection refused occurs. on 8080, respectively, nginx
can’t figure out why it’s so ... tell me plz

Answer 1

And you did not try to specify the interface?
iptables -t nat -A PREROUTING -i ethN -p tcp --dport $srcPortNumber -j REDIRECT --to-port $dstPortNumber

Answer 2

tried. does not help :( and indicated both one at a time (as a result there were 3 rules, on eth0 eth1 b lo) and -i all

Answer 3

The port redirect rule is correct:
Add more forwarding rules:
#-A FORWARD -i eth0 -o eth1 -j ACCEPT
#-A FORWARD -i eth1 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i eth0 -d $LOCAL_IP -j ACCEPT
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
I also recommend reading https://www.opennet.ru/base/net/nat_redirect.txt.html