From 84dd22a4ebee19bfa07ec8eb9228fe2a4746cfa4 Mon Sep 17 00:00:00 2001 From: teastep Date: Mon, 11 Dec 2006 15:57:41 +0000 Subject: [PATCH] Add note about ISPs blocking SYN,ACK git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@5094 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb --- docs/FAQ.xml | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/FAQ.xml b/docs/FAQ.xml index 50a6dc9e0..92e7aa5ef 100644 --- a/docs/FAQ.xml +++ b/docs/FAQ.xml @@ -253,6 +253,15 @@ DNAT net:<address> loc:<local IP addr matches OUT=<dev> and DEST= <ip>from the REJECT/DROP log message. + + + If everything seems to be correct according to these tests + but the connection doesn't work, it may be that your ISP is + blocking SYN,ACK responses. This technique allows your ISP to + detect when you are running a server (in violation of your service + agreement) and to stop connections to that server from being + established. +