From: Gert Doering Date: Fri, 25 Apr 2014 19:19:15 +0000 (+0200) Subject: Rewrite manpage section about --multihome X-Git-Tag: v2.4_alpha1~438 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abe18c69a61b42e5ac68b77f66198fc15be99e31;p=thirdparty%2Fopenvpn.git Rewrite manpage section about --multihome Part of the information was confusing, part was outdated, and part was just not making sense. Pointed out in trac#348. Also add note about Linux IPv4-mapped issues as per trac#306. Signed-off-by: Gert Doering Acked-by: Arne Schwabe Message-Id: <1398453555-19706-1-git-send-email-gert@greenie.muc.de> URL: http://article.gmane.org/gmane.network.openvpn.devel/8635 --- diff --git a/doc/openvpn.8 b/doc/openvpn.8 index ae3a4e0e2..f4925f185 100644 --- a/doc/openvpn.8 +++ b/doc/openvpn.8 @@ -2343,18 +2343,22 @@ is NOT specified. .\"********************************************************* .TP .B \-\-multihome -Configure a multi-homed UDP server. This option can be used when -OpenVPN has been configured to listen on all interfaces, and will -attempt to bind client sessions to the interface on which packets -are being received, so that outgoing packets will be sent out -of the same interface. Note that this option is only relevant for -UDP servers and currently is only implemented on Linux. - -Note: clients connecting to a -.B \-\-multihome -server should always use the -.B \-\-nobind -option. +Configure a multi-homed UDP server. This option needs to be used when +a server has more than one IP address (e.g. multiple interfaces, or +secondary IP addresses), and is not using +.B \-\-local +to force binding to one specific address only. This option will +add some extra lookups to the packet path to ensure that the UDP reply +packets are always sent from the address that the client is +talking to. This is not supported on all platforms, and it adds more +processing, so it's not enabled by default. + +Note: this option is only relevant for UDP servers. + +Note 2: if you do an IPv6+IPv4 dual-stack bind on a Linux machine with +multiple IPv4 address, connections to IPv4 addresses will not work +right on kernels before 3.14, due to missing kernel support for the +IPv4-mapped case. .\"********************************************************* .TP .B \-\-echo [parms...]