slight update

[rrq/rrqnet.git] / rrqnet-ifupdown.sh.8.adoc

diff --git a/rrqnet-ifupdown.sh.8.adoc b/rrqnet-ifupdown.sh.8.adoc
index bcca6a097e47e5181f49c47af9bea2082a6ef4f6..a922977223b18df3cba30524f0a55b610e4ec9f3 100644 (file)
--- a/rrqnet-ifupdown.sh.8.adoc
+++ b/rrqnet-ifupdown.sh.8.adoc
@@ -5,20 +5,20 @@ rrqnet-ifupdown.sh(8)
 
 NAME
 ----
-rrqnet-ifupdown.sh - an ifupdown script to uphold *rrqnet* cables by
-configuration in +/etc/network/interfaces+.
+rrqnet-ifupdown.sh - an ifupdown script to uphold rrqnet cables with
+iup and ifdown
 
 SYNOPSIS
 --------
-/etc/network/if-post-down.d/rrqnet -> /etc/rrqnet/ifupdown.sh
-/etc/network/if-pre-up.d/rrqnet -> /etc/rrqnet/ifupdown.sh
+ ln -s /etc/rrqnet/ifupdown.sh /etc/network/if-post-down.d/rrqnet
+ ln -s /etc/rrqnet/ifupdown.sh /etc/network/if-pre-up.d/rrqnet
 
 DESCRIPTION
 -----------
 
 */etc/rrqnet/ifupdown.sh* is a utility script for upholding +rrqnet+
 virtual cables via +/etc/network/interfaces+. The script is set up
-both as "pre-up" and "post-down" scripts for handling the associated
+as both "pre-up" and "post-down" scripts for handling the associated
 +rrqnet+ configurations to bring up and tear down virtual cable plugs
 over +tap+ interfaces.
 
@@ -55,7 +55,9 @@ configuration options ([-4] [-B n] [-T n] [-m mcast]). Refer to the
 
 This IFACE option is used for declaring the log level as one of +-v+,
 +-vv+ or +-vvv+, and to nominate the log file. If omitted, all the
-+rrqnet+ process output will be directed to +/dev/null+.
++rrqnet+ process output will be directed to +/dev/null+. If
+__pathname_ is of the form "facility.priority", then stderr is sent to
++syslog+. Otherwise, stderr is appended to the nominated file.
 
 *rrqnet_bridge* _bridge_::
 
@@ -74,7 +76,7 @@ iface mynet0 inet static
     address 10.0.0.2/24
     broadcast 10.0.0.255
     rrqnet_port 3636
-    rrqnet_options -4
+    rrqnet_options -4 -B 10 -T 1
     rrqnet_remote 111.222.333.444:3636=/sec/mynet.key
     rrqnet_log -v /var/log/mynet0.log
 ----
@@ -84,7 +86,9 @@ for UDP tunneling through host +111.222.333.444+, port +3636+, where
 the local +tap+, named +mynet0+, has ipv4 address +10.0.0.2+. The
 +rrqnet_port+ option is understood to identify the stanza as a virtual
 cabling set up which then is duly handled by +rrqnet-ifupdown.sh+, and
-all its options are used for declaring that tunneling.
+all its options are used for declaring that tunneling. The
++rrqnet_options+ in the example tells the +rrqnet+ process to use an
+ipv4-only socket, 10 packet buffers and a single delivery thread.
 
 NOTES
 -----
@@ -97,18 +101,18 @@ supervision.
 Note that the +rrqnet+ virtual cable requires real networking for its
 UDP tunnel traffic. The real packets will have a UDP header in
 addition to the orignal packet, which means that it grows packets with
-24 or 48 bytes (for ipv4 and ipv6 respectively). This may cause packet
-fragmentation of the tunneling packets unless the associated +tap+ is
-configured with that much smaller MTU than the real traffic.
+some 28/48 (ipv4/6) bytes. This may cause packet fragmentation of the
+tunneling packets which might be mitigated by configuring the
+associated +tap+ that much smaller MTU.
 
 SEE ALSO
 --------
 
-*interfaces(5)* - network interface configuration for ifup and ifdown
-*rrqnet(8)* - packet tunneling over UDP, multiple channels
-*brctl(8)* - ethernet bridge administration
-*daemon(1)* - turns other processes into daemons
-
+ *brctl(8)* - ethernet bridge administration
+ *daemon(1)* - turns other processes into daemons
+ *interfaces(5)* - network interface configuration for ifup and ifdown
+ *rrqnet(8)* - packet tunneling over UDP, multiple channels
+ 
 AUTHOR
 ------
 Ralph Rönnquist <ralph.ronnquist@gmail.com>