update plugin docs

[l2tpns.git] / Docs / manual.html

diff --git a/Docs/manual.html b/Docs/manual.html
index 59d6dbc..2458391 100644 (file)
--- a/Docs/manual.html
+++ b/Docs/manual.html
@@ -52,9 +52,11 @@ H3 {
     <LI><A HREF="#Interception">Interception</A></LI>
     <LI><A HREF="#Authentication">Authentication</A></LI>
     <LI><A HREF="#Plugins">Plugins</A></LI>
     <LI><A HREF="#Interception">Interception</A></LI>
     <LI><A HREF="#Authentication">Authentication</A></LI>
     <LI><A HREF="#Plugins">Plugins</A></LI>

-    <LI><A HREF="#Walled Garden">Walled Garden</A></LI>
+    <LI><A HREF="#WalledGarden">Walled Garden</A></LI>
+    <LI><A HREF="#Filtering">Filtering</A></LI>

     <LI><A HREF="#Clustering">Clustering</A></LI>
     <LI><A HREF="#Routing">Routing</A></LI>
     <LI><A HREF="#Clustering">Clustering</A></LI>
     <LI><A HREF="#Routing">Routing</A></LI>

+    <LI><A HREF="#AvoidingFragmentation">Avoiding Fragmentation</A></LI>

     <LI><A HREF="#Performance">Performance</A></LI>
 </OL>
 
     <LI><A HREF="#Performance">Performance</A></LI>
 </OL>
 


@@ -66,7 +68,7 @@ L2TP (Layer 2 Tunneling Protocol) is designed to allow any layer 2
 protocol (e.g. Ethernet, PPP) to be tunneled over an IP connection.  l2tpns
 implements PPP over L2TP only.<P>
 
 protocol (e.g. Ethernet, PPP) to be tunneled over an IP connection.  l2tpns
 implements PPP over L2TP only.<P>
 

-There are a couple of other L2TP imlementations, of which <A
+There are a couple of other L2TP implementations, of which <A

 HREF="http://sourceforge.net/projects/l2tpd">l2tpd</A> is probably the
 most popular.  l2tpd also will handle being either end of a tunnel, and
 is a lot more configurable than l2tpns.  However, due to the way it works,
 HREF="http://sourceforge.net/projects/l2tpd">l2tpd</A> is probably the
 most popular.  l2tpd also will handle being either end of a tunnel, and
 is a lot more configurable than l2tpns.  However, due to the way it works,


@@ -190,39 +192,52 @@ user, both a primary and a secondary.  If either is set to 0.0.0.0, then that
 one will not be sent.
 </LI>
 
 one will not be sent.
 </LI>
 

-<LI><B>save_state</B> (boolean)<BR>
-When l2tpns receives a STGTERM it will write out its current
-ip_address_pool, session and tunnel tables to disk prior to exiting to
-be re-loaded at startup.  The validity of this data is obviously quite
-short and the intent is to allow an sessions to be retained over a
-software upgrade.
-</LI>
-

 <LI><B>primary_radius</B> (ip address)
 <LI><B>secondary_radius</B> (ip address)<BR>
 <LI><B>primary_radius</B> (ip address)
 <LI><B>secondary_radius</B> (ip address)<BR>

-Sets the radius servers used for both authentication and accounting. 
-If the primary server does not respond, then the secondary radius
-server will be tried.
+Sets the RADIUS servers used for both authentication and accounting. 
+If the primary server does not respond, then the secondary RADIUS
+server will be tried.<br>
+<strong>Note:</strong> in addition to the source IP address and
+identifier, the RADIUS server <strong>must</strong> include the source
+port when detecting duplicates to supress (in order to cope with a
+large number of sessions comming on-line simultaneously l2tpns uses a
+set of udp sockets, each with a seperate identifier).

 </LI>
 
 <LI><B>primary_radius_port</B> (short)
 <LI><B>secondary_radius_port</B> (short)<BR>
 </LI>
 
 <LI><B>primary_radius_port</B> (short)
 <LI><B>secondary_radius_port</B> (short)<BR>

-Sets the authentication ports for the primary and secondary radius
+Sets the authentication ports for the primary and secondary RADIUS

 servers.  The accounting port is one more than the authentication
 servers.  The accounting port is one more than the authentication

-port.  If no radius ports are given, the authentication port defaults
+port.  If no RADIUS ports are given, the authentication port defaults

 to 1645, and the accounting port to 1646.
 </LI>
 
 <LI><B>radius_accounting</B> (boolean)<BR>
 to 1645, and the accounting port to 1646.
 </LI>
 
 <LI><B>radius_accounting</B> (boolean)<BR>

-If set to true, then radius accounting packets will be sent.  This
+If set to true, then RADIUS accounting packets will be sent.  This

 means that a Start record will be sent when the session is
 successfully authenticated, and a Stop record will be sent when the
 session is closed.
 </LI>
 
 <LI><B>radius_secret</B> (string)<BR>
 means that a Start record will be sent when the session is
 successfully authenticated, and a Stop record will be sent when the
 session is closed.
 </LI>
 
 <LI><B>radius_secret</B> (string)<BR>

-This secret will be used in all radius queries.  If this is not set then
-radius queries will fail.
+This secret will be used in all RADIUS queries.  If this is not set then
+RADIUS queries will fail.
+</LI>
+
+<LI><B>radius_authtypes</B> (string)</BR>
+A comma separated list of supported RADIUS authentication methods
+(<B>pap</B> or <B>chap</B>), in order of preference (default <B>pap</B>).
+</LI>
+
+<LI><B>radius_dae_port</B> (short)<BR>
+Port for DAE RADIUS (Packet of Death/Disconnect, Change of Authorization)
+requests (default: <B>3799</B>).
+</LI>
+
+<LI><B>allow_duplicate_users</B> (boolean)</BR>
+Allow multiple logins with the same username.  If false (the default),
+any prior session with the same username will be dropped when a new
+session is established.

 </LI>
 
 <LI><B>bind_address</B> (ip address)<BR>
 </LI>
 
 <LI><B>bind_address</B> (ip address)<BR>


@@ -276,10 +291,6 @@ second.  Even if this is disabled, you can see this information by running
 the <EM>uptime</EM> command on the CLI.
 </LI>
 
 the <EM>uptime</EM> command on the CLI.
 </LI>
 

-<LI><B>cleanup_interval</B> (int)<BR>
-Interval between regular cleanups (in seconds).
-</LI>
-

 <LI><B>multi_read_count</B> (int)<BR>
 Number of packets to read off each of the UDP and TUN fds when
 returned as readable by select (default:  10).  Avoids incurring the
 <LI><B>multi_read_count</B> (int)<BR>
 Number of packets to read off each of the UDP and TUN fds when
 returned as readable by select (default:  10).  Avoids incurring the


@@ -301,6 +312,13 @@ Keep all pages mapped by the l2tpns process in memory.
 Maximum number of host unreachable ICMP packets to send per second.
 </LI>
 
 Maximum number of host unreachable ICMP packets to send per second.
 </LI>
 

+<LI><B>packet_limit</B> (int><BR>
+Maximum number of packets of downstream traffic to be handled each
+tenth of a second per session.  If zero, no limit is applied (default: 
+0).  Intended as a DoS prevention mechanism and not a general
+throttling control (packets are dropped, not queued).
+</LI>
+

 <LI><B>cluster_address</B> (ip address)<BR>
 Multicast cluster address (default:  239.192.13.13).  See the section
 on <A HREF="#Clustering">Clustering</A> for more information.
 <LI><B>cluster_address</B> (ip address)<BR>
 Multicast cluster address (default:  239.192.13.13).  See the section
 on <A HREF="#Clustering">Clustering</A> for more information.


@@ -319,6 +337,11 @@ Cluster heartbeat timeout in tenths of a second.  A new master will be
 elected when this interval has been passed without seeing a heartbeat
 from the master.
 </LI>
 elected when this interval has been passed without seeing a heartbeat
 from the master.
 </LI>

+
+<LI><B>cluster_master_min_adv</B> (int)<BR>
+Determines the minumum number of up to date slaves required before the
+master will drop routes (default: 1).
+</LI>

 </UL>
 
 <P>BGP routing configuration is entered by the command:
 </UL>
 
 <P>BGP routing configuration is entered by the command:


@@ -338,6 +361,42 @@ Where <I>peer</I> specifies the BGP neighbour as either a hostname or
 IP address, <I>as</I> is the remote AS number and <I>keepalive</I>,
 <I>hold</I> are the timer values in seconds.
 
 IP address, <I>as</I> is the remote AS number and <I>keepalive</I>,
 <I>hold</I> are the timer values in seconds.
 

+<P>Named access-lists are configured using one of the commands:
+<DL>
+  <DD><B>ip access-list standard</B> <I>name</I>
+  <DD><B>ip access-list extended</B> <I>name</I>
+</DL>
+
+<P>Subsequent lines prefixed with <B>permit</B> or <B>deny</B>
+define the body of the access-list.  Standard access-list syntax:
+<DL>
+  <DD>{<B>permit</B>|<B>deny</B>}
+    {<I>host</I>|<I>source source-wildcard</I>|<B>any</B>}
+    [{<I>host</I>|<I>destination destination-wildcard</I>|<B>any</B>}]
+</DL>
+
+Extended access-lists:
+
+<DIV STYLE="margin-left: 4em; text-indent: -2em">
+  <P>{<B>permit</B>|<B>deny</B>} <B>ip</B>
+    {<I>host</I>|<I>source source-wildcard</I>|<B>any</B>}
+    {<I>host</I>|<I>destination destination-wildcard</I>|<B>any</B>} [<B>fragments</B>]
+  <P>{<B>permit</B>|<B>deny</B>} <B>udp</B>
+    {<I>host</I>|<I>source source-wildcard</I>|<B>any</B>}
+       [{<B>eq</B>|<B>neq</B>|<B>gt</B>|<B>lt</B>} <I>port</I>|<B>range</B> <I>from</I> <I>to</I>]
+    {<I>host</I>|<I>destination destination-wildcard</I>|<B>any</B>}
+       [{<B>eq</B>|<B>neq</B>|<B>gt</B>|<B>lt</B>} <I>port</I>|<B>range</B> <I>from</I> <I>to</I>]
+       [<B>fragments</B>]
+  <P>{<B>permit</B>|<B>deny</B>} <B>tcp</B>
+    {<I>host</I>|<I>source source-wildcard</I>|<B>any</B>}
+       [{<B>eq</B>|<B>neq</B>|<B>gt</B>|<B>lt</B>} <I>port</I>|<B>range</B> <I>from</I> <I>to</I>]
+    {<I>host</I>|<I>destination destination-wildcard</I>|<B>any</B>}
+       [{<B>eq</B>|<B>neq</B>|<B>gt</B>|<B>lt</B>} <I>port</I>|<B>range</B> <I>from</I> <I>to</I>]
+       [{<B>established</B>|{<B>match-any</B>|<B>match-all</B>}
+           {<B>+</B>|<B>-</B>}{<B>fin</B>|<B>syn</B>|<B>rst</B>|<B>psh</B>|<B>ack</B>|<B>urg</B>}
+           ...|<B>fragments</B>]
+</DIV>
+

 <H3 ID="users">users</H3>
 
 Usernames and passwords for the command-line interface are stored in
 <H3 ID="users">users</H3>
 
 Usernames and passwords for the command-line interface are stored in


@@ -500,19 +559,19 @@ IP Address      Used  Session User
 </LI>
 
 <LI><B>show radius</B><BR>
 </LI>
 
 <LI><B>show radius</B><BR>

-Show a summary of the in-use radius sessions.  This list should not be very
-long, as radius sessions should be cleaned up as soon as they are used.  The
+Show a summary of the in-use RADIUS sessions.  This list should not be very
+long, as RADIUS sessions should be cleaned up as soon as they are used.  The

 columns listed are:
 <TABLE>
 columns listed are:
 <TABLE>

-       <TR><TD><B>Radius</B></TD><TD>The ID of the radius request.  This is
-       sent in the packet to the radius server for identification.</TD></TR>
+       <TR><TD><B>Radius</B></TD><TD>The ID of the RADIUS request.  This is
+       sent in the packet to the RADIUS server for identification.</TD></TR>

        <TR><TD><B>State</B></TD><TD>The state of the request - WAIT, CHAP,
        AUTH, IPCP, START, STOP, NULL.</TD></TR>
        <TR><TD><B>State</B></TD><TD>The state of the request - WAIT, CHAP,
        AUTH, IPCP, START, STOP, NULL.</TD></TR>

-       <TR><TD><B>Session</B></TD><TD>The session ID that this radius
+       <TR><TD><B>Session</B></TD><TD>The session ID that this RADIUS

        request is associated with</TD></TR>
        <TR><TD><B>Retry</B></TD><TD>If a response does not appear to the
        request, it will retry at this time.  This is a unix timestamp.</TD></TR>
        request is associated with</TD></TR>
        <TR><TD><B>Retry</B></TD><TD>If a response does not appear to the
        request, it will retry at this time.  This is a unix timestamp.</TD></TR>

-       <TR><TD><B>Try</B></TD><TD>Retry count.  The radius request is
+       <TR><TD><B>Try</B></TD><TD>Retry count.  The RADIUS request is

        discarded after 3 retries.</TD></TR>
 </TABLE>
 <P>
        discarded after 3 retries.</TD></TR>
 </TABLE>
 <P>


@@ -553,7 +612,7 @@ current session for that username will be forwarded to the given
 host/port.  Specify <EM>no snoop username</EM> to disable interception
 for the session.<P>
 
 host/port.  Specify <EM>no snoop username</EM> to disable interception
 for the session.<P>
 

-If you want interception to be permanent, you will have to modify the radius
+If you want interception to be permanent, you will have to modify the RADIUS

 response for the user.  See <A HREF="#Interception">Interception</A>.
 <P>
 </LI>
 response for the user.  See <A HREF="#Interception">Interception</A>.
 <P>
 </LI>


@@ -564,7 +623,7 @@ session.  Specify <EM>no throttle username</EM> to disable throttling
 for the current session.<P>
 
 If you want throttling to be permanent, you will have to modify the
 for the current session.<P>
 
 If you want throttling to be permanent, you will have to modify the

-radius response for the user.  See <A HREF="#THrottling">Throttling</A>.
+RADIUS response for the user.  See <A HREF="#Throttling">Throttling</A>.

 <P>
 </LI>
 
 <P>
 </LI>
 


@@ -642,16 +701,15 @@ killall -HUP l2tpns
 </PRE>
 
 The signals understood are:
 </PRE>
 
 The signals understood are:

-<UL>
-<LI>SIGHUP - Reload the config from disk and re-open log file<P></LI>
-<LI>SIGTERM / SIGINT - Shut down for a restart.  This will dump the current
-state to disk (if <EM>save_state</EM> is set to true).  Upon restart, the
-process will read this saved state to resume active sessions.<P>
-<LI>SIGQUIT - Shut down cleanly.  This will send a disconnect message for
-every active session and tunnel before shutting down.  This is a good idea
-when upgrading the code, as no sessions will be left with the remote end
-thinking they are open.</LI>
-</UL>
+<DL>
+<DT>SIGHUP</DT><DD>Reload the config from disk and re-open log file.</DD>
+<DT>SIGTERM, SIGINT</DT><DD>Stop process.  Tunnels and sessions are not
+terminated.  This signal should be used to stop l2tpns on a
+<A HREF="#Clustering">cluster node</A> where there are other machines to
+continue handling traffic.</DD>
+<DT>SIGQUIT</DT><DD>Shut down tunnels and sessions, exit process when
+complete.</DD>
+</DL>

 
 <H2 ID="Throttling">Throttling</H2>
 
 
 <H2 ID="Throttling">Throttling</H2>
 


@@ -660,7 +718,7 @@ desire.  You must first enable the global setting <EM>throttle_speed</EM>
 before this will be activated.<P>
 
 If you wish a session to be throttled permanently, you should set the
 before this will be activated.<P>
 
 If you wish a session to be throttled permanently, you should set the

-Vendor-Specific radius value <B>Cisco-Avpair="throttle=yes"</B>, which
+Vendor-Specific RADIUS value <B>Cisco-Avpair="throttle=yes"</B>, which

 will be handled by the <EM>autothrottle</EM> module.<P>
 
 Otherwise, you can enable and disable throttling an active session using
 will be handled by the <EM>autothrottle</EM> module.<P>
 
 Otherwise, you can enable and disable throttling an active session using


@@ -684,7 +742,7 @@ and <EM>no snoop username</EM> CLI commands.  These will enable interception
 immediately.<P>
 
 If you wish the user to be intercepted whenever they reconnect, you will
 immediately.<P>
 
 If you wish the user to be intercepted whenever they reconnect, you will

-need to modify the radius response to include the Vendor-Specific value
+need to modify the RADIUS response to include the Vendor-Specific value

 <B>Cisco-Avpair="intercept=yes"</B>.  For this feature to be enabled,
 you need to have the <EM>autosnoop</EM> module loaded.<P>
 
 <B>Cisco-Avpair="intercept=yes"</B>.  For this feature to be enabled,
 you need to have the <EM>autosnoop</EM> module loaded.<P>
 


@@ -694,11 +752,11 @@ Whenever a session connects, it is not fully set up until authentication is
 completed.  The remote end must send a PPP CHAP or PPP PAP authentication
 request to l2tpns.<P>
 
 completed.  The remote end must send a PPP CHAP or PPP PAP authentication
 request to l2tpns.<P>
 

-This request is sent to the radius server, which will hopefully respond with
+This request is sent to the RADIUS server, which will hopefully respond with

 Auth-Accept or Auth-Reject.<P>
 
 If Auth-Accept is received, the session is set up and an IP address is
 Auth-Accept or Auth-Reject.<P>
 
 If Auth-Accept is received, the session is set up and an IP address is

-assigned.  The radius server can include a Framed-IP-Address field in the
+assigned.  The RADIUS server can include a Framed-IP-Address field in the

 reply, and that address will be assigned to the client.  It can also include
 specific DNS servers, and a Framed-Route if that is required.<P>
 
 reply, and that address will be assigned to the client.  It can also include
 specific DNS servers, and a Framed-Route if that is required.<P>
 


@@ -708,7 +766,7 @@ walled garden module is loaded, in which case the user still receives the
 PPP AUTHACK, but their session is flagged as being a garden'd user, and they
 should not receive any service.<P>
 
 PPP AUTHACK, but their session is flagged as being a garden'd user, and they
 should not receive any service.<P>
 

-The radius reply can also contain a Vendor-Specific attribute called
+The RADIUS reply can also contain a Vendor-Specific attribute called

 Cisco-Avpair.  This field is a freeform text field that most Cisco
 devices understand to contain configuration instructions for the session.  In
 the case of l2tpns it is expected to be of the form
 Cisco-Avpair.  This field is a freeform text field that most Cisco
 devices understand to contain configuration instructions for the session.  In
 the case of l2tpns it is expected to be of the form


@@ -758,39 +816,39 @@ supplied structure:
 <TABLE CELLSPACING=1 CELLPADDING=3>
        <TR BGCOLOR=LIGHTGREEN><TH><B>Event</B></TH><TH><B>Description</B></TH><TH><B>Parameters</B></TH></TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>pre_auth</B></TD>
 <TABLE CELLSPACING=1 CELLPADDING=3>
        <TR BGCOLOR=LIGHTGREEN><TH><B>Event</B></TH><TH><B>Description</B></TH><TH><B>Parameters</B></TH></TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>pre_auth</B></TD>

-               <TD>This is called after a radius response has been
+               <TD>This is called after a RADIUS response has been

                received, but before it has been processed by the
                code.  This will allow you to modify the response in
                some way.
                </TD>
                <TD>
                received, but before it has been processed by the
                code.  This will allow you to modify the response in
                some way.
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-                       <LI>username</LI>
-                       <LI>password</LI>
-                       <LI>protocol (0xC023 for PAP, 0xC223 for CHAP)</LI>
-                       <LI>continue_auth - Set to 0 to stop processing authentication modules</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+                       <DT>username
+                       <DT>password
+                       <DT>protocol<DD>0xC023 for PAP, 0xC223 for CHAP
+                       <DT>continue_auth<DD>Set to 0 to stop processing authentication modules
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>post_auth</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>post_auth</B></TD>

-               <TD>This is called after a radius response has been
+               <TD>This is called after a RADIUS response has been

                received, and the basic checks have been performed.  This
                is what the garden module uses to force authentication
                to be accepted.
                </TD>
                <TD>
                received, and the basic checks have been performed.  This
                is what the garden module uses to force authentication
                to be accepted.
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-                       <LI>username</LI>
-                       <LI>auth_allowed - This is already set to true or
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+                       <DT>username
+                       <DT>auth_allowed<DD>This is already set to true or

                        false depending on whether authentication has been
                        allowed so far.  You can set this to 1 or 0 to force
                        false depending on whether authentication has been
                        allowed so far.  You can set this to 1 or 0 to force

-                       allow or disallow authentication</LI>
-                       <LI>protocol (0xC023 for PAP, 0xC223 for CHAP)</LI>
-               </UL>
+                       allow or disallow authentication
+                       <DT>protocol<DD>0xC023 for PAP, 0xC223 for CHAP
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>packet_rx</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>packet_rx</B></TD>


@@ -799,12 +857,12 @@ supplied structure:
                seriously slow down the system.</FONT>
                </TD>
                <TD>
                seriously slow down the system.</FONT>
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-                       <LI>buf - The raw packet data</LI>
-                       <LI>len - The length of buf</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+                       <DT>buf<DD>The raw packet data
+                       <DT>len<DD>The length of buf
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>packet_tx</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>packet_tx</B></TD>


@@ -813,12 +871,12 @@ supplied structure:
                seriously slow down the system.</FONT>
                </TD>
                <TD>
                seriously slow down the system.</FONT>
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-                       <LI>buf - The raw packet data</LI>
-                       <LI>len - The length of buf</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+                       <DT>buf<DD>The raw packet data
+                       <DT>len<DD>The length of buf
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>timer</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>timer</B></TD>


@@ -827,9 +885,9 @@ supplied structure:
                you do is reentrant.
                </TD>
                <TD>
                you do is reentrant.
                </TD>
                <TD>

-               <UL>
-                       <LI>time_now - The current unix timestamp</LI>
-               </UL>
+               <DL>
+                       <DT>time_now<DD>The current unix timestamp
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>new_session</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>new_session</B></TD>


@@ -837,10 +895,10 @@ supplied structure:
                session is now ready to handle traffic.
                </TD>
                <TD>
                session is now ready to handle traffic.
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>kill_session</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>kill_session</B></TD>


@@ -848,25 +906,37 @@ supplied structure:
                This may be called multiple times for the same session.
                </TD>
                <TD>
                This may be called multiple times for the same session.
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>radius_response</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>radius_response</B></TD>

-               <TD>This is called whenever a radius response includes a
+               <TD>This is called whenever a RADIUS response includes a

                Cisco-Avpair value.  The value is split up into
                <EM>key=value</EM> pairs, and each is processed through all
                modules.
                </TD>
                <TD>
                Cisco-Avpair value.  The value is split up into
                <EM>key=value</EM> pairs, and each is processed through all
                modules.
                </TD>
                <TD>

-               <UL>
-                       <LI>t - Tunnel ID</LI>
-                       <LI>s - Session ID</LI>
-                       <LI>key</LI>
-                       <LI>value</LI>
-               </UL>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+                       <DT>key
+                       <DT>value
+               </DL>
+               </TD>
+       </TR>
+       <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>radius_reset</B></TD>
+               <TD>This is called whenever a RADIUS CoA request is
+               received to reset any options to default values before
+               the new values are applied.
+               </TD>
+               <TD>
+               <DL>
+                       <DT>t<DD>Tunnel
+                       <DT>s<DD>Session
+               </DL>

                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>control</B></TD>
                </TD>
        </TR>
        <TR VALIGN=TOP BGCOLOR=WHITE><TD><B>control</B></TD>


@@ -875,21 +945,13 @@ supplied structure:
                required.
                </TD>
                <TD>
                required.
                </TD>
                <TD>

-               <UL>
-                       <LI>buf - The raw packet data</LI>
-                       <LI>l - The raw packet data length</LI>
-                       <LI>source_ip - Where the request came from</LI>
-                       <LI>source_port - Where the request came from</LI>
-                       <LI>response - Allocate a buffer and put your response in here</LI>
-                       <LI>response_length - Length of response</LI>
-                       <LI>send_response - true or false whether a response
-                       should be sent.  If you set this to true, you must
-                       allocate a response buffer.</LI>
-                       <LI>type - Type of request (see nsctl.c)</LI>
-                       <LI>id - ID of request</LI>
-                       <LI>data - I'm really not sure</LI>
-                       <LI>data_length - Length of data</LI>
-               </UL>
+               <DL>
+                       <DT>iam_master<DD>Cluster master status
+                       <DT>argc<DD>The number of arguments
+                       <DT>argv<DD>Arguments
+                       <DT>response<DD>Return value: NSCTL_RES_OK or NSCTL_RES_ERR
+                       <DT>additional<DD>Extended response text
+               </DL>

                </TD>
        </TR>
 </TABLE>
                </TD>
        </TR>
 </TABLE>


@@ -901,7 +963,7 @@ Walled Garden is implemented so that you can provide perhaps limited service
 to sessions that incorrectly authenticate.<P>
 
 Whenever a session provides incorrect authentication, and the
 to sessions that incorrectly authenticate.<P>
 
 Whenever a session provides incorrect authentication, and the

-radius server responds with Auth-Reject, the walled garden module
+RADIUS server responds with Auth-Reject, the walled garden module

 (if loaded) will force authentication to succeed, but set the flag
 <EM>garden</EM> in the session structure, and adds an iptables rule to
 the <B>garden_users</B> chain to force all packets for the session's IP
 (if loaded) will force authentication to succeed, but set the flag
 <EM>garden</EM> in the session structure, and adds an iptables rule to
 the <B>garden_users</B> chain to force all packets for the session's IP


@@ -926,6 +988,14 @@ command:
 iptables -t nat -L garden -nvx
 </PRE>
 
 iptables -t nat -L garden -nvx
 </PRE>
 

+<H2 ID="Filtering">Filtering</H2>
+
+Sessions may be filtered by specifying <B>Filter-Id</B> attributes in
+the RADIUS reply.  <I>filter</I>.<B>in</B> specifies that the named
+access-list <I>filter</I> should be applied to traffic from the
+customer, <I>filter</I>.<B>out</B> specifies a list for traffic to the
+customer.
+

 <H2 ID="Clustering">Clustering</H2>
 
 An l2tpns cluster consists of of one* or more servers configured with
 <H2 ID="Clustering">Clustering</H2>
 
 An l2tpns cluster consists of of one* or more servers configured with


@@ -973,6 +1043,22 @@ ibgp" for IBGP.  If this is not supported by your IOS revision, you
 can use "maximum-paths" (which works for EBGP) and set
 <B>as_number</B> to a private value such as 64512.<P>
 
 can use "maximum-paths" (which works for EBGP) and set
 <B>as_number</B> to a private value such as 64512.<P>
 

+<H2 ID="AvoidingFragmentation">Avoiding Fragmentation</H2>
+
+Fragmentation of encapsulated return packets to the LAC may be avoided
+for TCP sessions by adding a firewall rule to clamps the MSS on
+outgoing SYN packets.
+
+The following is appropriate for interfaces with a typical MTU of
+1500:
+
+<pre>
+iptables -A FORWARD -i tun+ -o eth0    \
+    -p tcp --tcp-flags SYN,RST SYN     \
+    -m tcpmss --mss 1413:1600          \
+    -j TCPMSS --set-mss 1412
+</pre>
+

 <H2 ID="Performance">Performance</H2>
 
 Performance is great.<P>
 <H2 ID="Performance">Performance</H2>
 
 Performance is great.<P>