ipv4: Clarify in docs that accept_local requires rp_filter.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 99d0e0504d6eb9570cf064ee622de0cd7b2051f7..47b6c79e9b05a55823176be78125221613f35252 100644 (file)
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -857,9 +857,14 @@ accept_source_route - BOOLEAN
                FALSE (host)
 
 accept_local - BOOLEAN
-       Accept packets with local source addresses. In combination with
-       suitable routing, this can be used to direct packets between two
-       local interfaces over the wire and have them accepted properly.
+       Accept packets with local source addresses. In combination
+       with suitable routing, this can be used to direct packets
+       between two local interfaces over the wire and have them
+       accepted properly.
+
+       rp_filter must be set to a non-zero value in order for
+       accept_local to have an effect.
+
        default FALSE
 
 route_localnet - BOOLEAN