From: Łukasz Stelmach Date: Thu, 21 Aug 2025 10:38:40 +0000 (+0200) Subject: doc: Add a note about route_localnet sysctl X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=refs%2Fheads%2Fmaster;p=thirdparty%2Fnftables.git doc: Add a note about route_localnet sysctl See ip_route_input_slow() in net/ipv4/route.c in the Linux kernel sources. Signed-off-by: Łukasz Stelmach Signed-off-by: Florian Westphal --- diff --git a/doc/statements.txt b/doc/statements.txt index 4aeb0a73..6226713b 100644 --- a/doc/statements.txt +++ b/doc/statements.txt @@ -459,6 +459,11 @@ netfilter and therefore no reverse translation will take place. The optional *prefix* keyword allows to map *n* source addresses to *n* destination addresses. See 'Advanced NAT examples' below. +If the 'address' for *dnat* is an IPv4 loopback address +(i.e. 127.0.0.0/8) the "net.ipv4.conf.*.route_localnet" sysctl for the +input interface needs to be set to 1. Otherwise packets will be +dropped by the routing code as "martians". + .NAT statement values [options="header"] |==================