Documented --ip-win32 adaptive.

git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@768 e7ae566f-a301-0410-adde-c780ea21d3b5

ChangeLog

@@ -11,7 +11,8 @@ $Id$
 * Moved easy-rsa 2.0 scripts to easy-rsa/2.0 to
   be compatible with 2.0.x distribution.
 * Documented --route-nopull.
-
+* Documented --ip-win32 adaptive.
+	
 2005.11.01 -- Version 2.1-beta6
 
 * Security fix (merged from 2.0.4) -- Affects non-Windows

openvpn.8

@@ -4169,7 +4169,7 @@ adapter manually and indicating the IP/netmask which
 OpenVPN expects the adapter to be set to.
 
 .B dynamic [offset] [lease-time] --
-(Default) Automatically set the IP address and netmask by replying to
+Automatically set the IP address and netmask by replying to
 DHCP query messages generated by the kernel.  This mode is
 probably the "cleanest" solution
 for setting the TCP/IP properties since it uses the well-known
@@ -4220,6 +4220,35 @@ that it works okay in practice.  If you use this option,
 it is best to leave the TCP/IP properties for the TAP-Win32
 adapter in their default state, i.e. "Obtain an IP address
 automatically."
+
+.B adaptive --
+(Default) Try
+.B dynamic
+method initially and fail over to
+.B netsh
+if the DHCP negotiation with the TAP-Win32 adapter does
+not succeed in 20 seconds.  Such failures have been known
+to occur when certain third-party firewall packages installed
+on the client machine block the DHCP negotiation used by
+the TAP-Win32 adapter.
+Note that if the
+.B netsh
+failover occurs, the TAP-Win32 adapter
+TCP/IP properties will be reset from DHCP to static, and this
+will cause future OpenVPN startups using the
+.B adaptive
+mode to use
+.B netsh
+immediately, rather than trying
+.B dynamic
+first.  To "unstick" the
+.B adaptive
+mode from using
+.B netsh,
+run OpenVPN at least once using the
+.B dynamic
+mode to restore the TAP-Win32 adapter TCP/IP properties
+to a DHCP configuration.
 .\"*********************************************************
 .TP
 .B --route-method m

options.c

@@ -499,8 +499,8 @@ static const char usage_message[] =
   "\n"
   "Windows Specific:\n"
   "--ip-win32 method : When using --ifconfig on Windows, set TAP-Win32 adapter\n"
-  "                    IP address using method = manual, netsh, ipapi, or\n"
-  "                    dynamic (default = ipapi).\n"
+  "                    IP address using method = manual, netsh, ipapi,\n"
+  "                    dynamic, or adaptive (default = adaptive).\n"
   "                    Dynamic method allows two optional parameters:\n"
   "                    offset: DHCP server address offset (> -256 and < 256).\n"
   "                            If 0, use network address, if >0, take nth\n"