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Revision: 1.2
Committed: Mon Mar 24 15:20:24 2003 UTC (21 years, 2 months ago) by pcg
Branch: MAIN
Changes since 1.1: +15 -15 lines
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# Content
1 =head1 NAME
2
3 vped.conf - vpe daemon configuration file
4
5 =head1 SYNOPSIS
6
7 udp-port = 407
8 mtu = 1492
9 ifname = vpn0
10
11 node = branch1
12 hostname = 1.2.3.4
13
14 node = branch2
15 hostname = www.example.net
16 udp-port = 500 # this host uses a different udp-port
17
18 node = branch3
19 connect = ondemand
20
21 =head1 DESCRIPTION
22
23 The vpe config file consists of a series of lines that contain C<variable
24 = value> pairs. Empty lines are ignored. Comments start with a C<#> and
25 extend to the end of the line. They can be used on their own lines, or
26 after any directives. Spaces are allowed before or after the C<=> sign or
27 after values, but not within the variable names or values themselves.
28
29 The only exception to the above is the "on" directive that can prefix any
30 C<name = value> setting and will only "execute" it on the named node, or
31 (if the nodename starts with "!") on all nodes except the named one.
32
33 name = value
34 on branch1 loglevel = noise
35 on !branch2 connect = ondemand
36
37 All settings are executed "in order", that is, later settings of the same
38 variable overwrite earlier ones.
39
40 =head1 ANATOMY OF A CONFIG FILE
41
42 Usually, a config file starts with global settings (like the udp port to
43 listen on), followed by node-specific sections that begin with a C<node =
44 nickname> line.
45
46 Every node that is part of the network must have a section that starts
47 with C<node = nickname>. The number and order of the nodes is important
48 and must be the same on all hosts. It is not uncommon for node sections to
49 be completely empty - if the default values are right.
50
51 Node-specific settings can be used at any time. If used before the first
52 node section they will set the default values for all following nodes.
53
54 =head1 CONFIG VARIABLES
55
56 =head2 GLOBAL SETTINGS
57
58 Global settings will affect the behaviour of the running vped daemon, that
59 is, they are in some sense node-specific (config files can set different
60 values on different nodes using C<on>), but will affect the behaviour of
61 the vped daemon and all connections it creates.
62
63 =over 4
64
65 =item loglevel = noise|trace|debug|info|notice|warn|error|critical
66
67 Set the logging level. Connection established messages are logged at level
68 C<info>, notable errors are logged with C<error>. Default is C<info>.
69
70 =item node = nickname
71
72 Not really a config setting but introduces a node section. The nickname is
73 used to select the right configuration section and must be passed as an
74 argument to the vped daemon.
75
76 =item private-key = relative-path-to-key
77
78 Sets the path (relative to the config directory) to the private key
79 (default: C<hostkey>). This is a printf format string so every C<%> must
80 be doubled. A single C<%s> is replaced by the hostname, so you could
81 use paths like C<hostkeys/%s> to fetch the files at the location where
82 C<vpectrl> puts them.
83
84 Since only the private key file of the current node is used and the
85 private key file should be kept secret per-host to avoid spoofings, it is
86 not recommended to use this feature.
87
88 =item ifpersist = yes|no
89
90 Should the tun/tap device be made persistent, that is, should the device
91 stay up even when vped exits? Some versions of the tunnel device have
92 problems sending packets when vped is restarted in persistent mode, so
93 if the connections can be established but you cannot send packets from
94 the local node, try to set this to C<off> and do an ifconfig down on the
95 device.
96
97 =item ifname = devname
98
99 Sets the tun interface name to the given name. The default is OS-specific
100 and most probably something like C<tun0>.
101
102 =item rekey = seconds
103
104 Sets the rekeying interval in seconds (default: C<3600>). Connections are
105 reestablished every C<rekey> seconds.
106
107 =item keepalive = seconds
108
109 Sets the keepalive probe interval in seconds (default: C<60>). After this
110 many seconds of inactivity the daemon will start to send keepalive probe
111 every 5 seconds until it receives a reply from the other end. If no reply
112 is received within 30 seconds, the peer is considered unreachable and the
113 connection is closed.
114
115 =item mtu = bytes
116
117 Sets the maximum MTU that should be used on outgoing packets (basically
118 the MTU of the outgoing interface) The daemon will automatically calculate
119 maximum overhead (e.g. udp header size, encryption blocksize...) and pass
120 this information to the C<if-up> script.
121
122 Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
123
124 This value must be the minimum of the mtu values of all hosts.
125
126 =item if-up = relative-or-absolute-path
127
128 Sets the path of a script that should be called immediately after the
129 network interface is initialized (but not neccessarily up). The following
130 environment variables are passed to it (the values are just examples):
131
132 =over 4
133
134 =item CONFBASE=/etc/vpe
135
136 The configuration base directory.
137
138 =item IFNAME=vpn0
139
140 The interface to initialize.
141
142 =item MTU=1436
143
144 The MTU to set the interface to. You can use lower values (if done
145 consistently on all hosts), but this is usually ineffective.
146
147 =item MAC=fe:fd:80:00:00:01
148
149 The MAC address to set the interface to. The script *must* set the
150 interface MAC to this value. On GNU/Linux you will most likely use this:
151
152 ip link set $IFNAME address $MAC mtu $MTU up
153
154 =item NODENAME=branch1
155
156 The nickname of the current node, as passed to the vped daemon.
157
158 =item NODEID=1
159
160 The numerical node id of the current node. The first node mentioned in the
161 config file gets ID 1, the second ID 2 and so on.
162
163 =back
164
165 Here is a simple if-up script:
166
167 #!/bin/sh
168 ip link set $IFNAME address $MAC mtu $MTU up
169 [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME
170 [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME
171 ip route add 10.0.0.0/8 dev $IFNAME
172
173 More complicated examples (using routing to reduce arp traffic) can be
174 found in the etc/ subdirectory of the distribution.
175
176 =item node-up = relative-or-absolute-path
177
178 Sets a command (default: no script) that should be called whenever a
179 connection is established (even on rekeying operations). In addition
180 to the variables passed to C<if-up> scripts, the following environment
181 variables will be set:
182
183 =over 4
184
185 =item DESTNODE=branch2
186
187 The name of the remote node.
188
189 =item DESTID=2
190
191 The node id of the remote node.
192
193 =item DESTIP=188.13.66.8
194
195 The numerical IP address of the remote host (vped accepts connections from
196 everywhere, as long as the other host can authenticate itself).
197
198 =item DESTPORT=407 # deprecated
199
200 The UDP port used by the other side.
201
202 =item STATE=UP
203
204 Node-up scripts get called with STATE=UP, node-down scripts get called
205 with STATE=DOWN.
206
207 =back
208
209 Here is a nontrivial example that uses nsupdate to update the name => ip
210 mapping in some dns zone:
211
212 #!/bin/sh
213 {
214 echo update delete $DESTNODE.lowttl.example.net. a
215 echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP
216 echo
217 } | nsupdate -d -k $CONFBASE:key.example.net.
218
219 =item node-down = relative-or-absolute-path
220
221 Same as C<node-up>, but gets called whenever a connection is lost.
222
223 =back
224
225 =head2 NODE SPECIFIC SETTINGS
226
227 The following settings are node-specific, that is, every node can have
228 different settings, even within the same vped instance. Settings that are
229 executed before the first node section set the defaults, settings that are
230 executed within a node section only apply to the given node.
231
232 =over 4
233
234 =item udp-port = port-number
235
236 Sets the port number used by the UDP protocol (default: C<407>, not
237 officially assigned by IANA!).
238
239 =item router-priority = positive-number
240
241 Sets the router priority of the given host (default: C<0>, disabled). If
242 some host tries to connect to another host without a hostname, it asks
243 the router host for it's IP address. The router host is the one with the
244 highest priority that is currently reachable. Make sure all clients always
245 connect to the router hosts, otherwise conencting to them is impossible.
246
247 =item connect = ondemand|never|always|disabled
248
249 Sets the connect mode (default: C<always>). It can be C<always> (always
250 try to establish and keep a conenction to the given host), C<never>
251 (nevr initiate a connection to the given host, but accept connections),
252 C<ondemand> (try to establish a connection on the first packet sent, and
253 take it down after the keepalive interval) or C<disabled> (node is bad,
254 don't talk to it).
255
256 =item inherit-tos = yes|no
257
258 Wether to inherit the TOS settings of packets sent to the tunnel when
259 sending packets to this node (default: C<yes>). If set to C<yes> then
260 outgoing tunnel packets will have the same TOS setting as the packets sent
261 to the tunnel device, which is usually what you want.
262
263 =item compress = yes|no
264
265 Wether to compress data packets sent to this host (default: C<yes>,
266 compression is really cheap even on slow computers and has no size
267 overhead at all).
268
269 =back
270
271 =head1 CONFIG DIRECTORY LAYOUT
272
273 The default (or recommended) directory layout for the config directory is:
274
275 =over 4
276
277 =item vped.conf
278
279 The config file.
280
281 =item if-up
282
283 The if-up script
284
285 =item node-up, node-down
286
287 If used the node up or node-down scripts.
288
289 =item hostkey
290
291 The private key (taken from C<hostkeys/nodename>) of the current host.
292
293 =item pubkey/nodename
294
295 The public keys of the other nodes, one file per node.
296
297 =back
298
299 =head1 SEE ALSO
300
301 vpe(8), vped(8), vpectrl(8).
302
303 =head1 AUTHOR
304
305 Marc Lehmann <vpe@plan9.de>
306