Re: Redirect incoming connection on a given interface to the loopback interface

Le 07/04/2023 à 09꞉33, Olivier Sannier a écrit :
> So I tried this rule:
>
> DNAT:INFO:mqtt          loc     $FW:127.0.0.1:1883 tcp     1883    
> -       &enp4s0
>
> And it gives me the "martian sources" error that I already mentioned

Well, as it turns out, this is because I'm targeting a local IP address 
and the kernel considers 127/8 as a martian by default.
Setting net.ipv4.conf.all.route_localnet to 1 with sysctl allows local 
routing and then this rule works just fine.

I could not find a setting for this in shorewall.conf, but it's easy 
enough to have it applied at every boot, so I'm fine.