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Revision: 1.30
Committed: Tue Dec 4 10:29:43 2012 UTC (11 years, 5 months ago) by root
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124 .\" ========================================================================
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126 .IX Title "GVPE.CONF 5"
127 .TH GVPE.CONF 5 "2012-07-06" "2.24" "GNU Virtual Private Ethernet"
128 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
129 .\" way too many mistakes in technical documents.
130 .if n .ad l
131 .nh
132 .SH "NAME"
133 gvpe.conf \- configuration file for the GNU VPE daemon
134 .SH "SYNOPSIS"
135 .IX Header "SYNOPSIS"
136 .Vb 4
137 \& # global options for all nodes
138 \& udp\-port = 407
139 \& mtu = 1492
140 \& ifname = vpn0
141 \&
142 \& # first node is named branch1 and is at 1.2.3.4
143 \& node = branch1
144 \& hostname = 1.2.3.4
145 \&
146 \& # second node uses dns to resolve the address
147 \& node = branch2
148 \& hostname = www.example.net
149 \& udp\-port = 500 # this host uses a different udp\-port
150 \&
151 \& # third node has no fixed ip address
152 \& node = branch3
153 \& connect = ondemand
154 .Ve
155 .SH "DESCRIPTION"
156 .IX Header "DESCRIPTION"
157 The gvpe config file consists of a series of lines that contain \f(CW\*(C`variable
158 = value\*(C'\fR pairs. Empty lines are ignored. Comments start with a \f(CW\*(C`#\*(C'\fR and
159 extend to the end of the line. They can be used on their own lines, or
160 after any directives. Whitespace is allowed around the \f(CW\*(C`=\*(C'\fR sign or after
161 values, but not within the variable names or values themselves.
162 .PP
163 All settings are applied \*(L"in order\*(R", that is, later settings of the same
164 variable overwrite earlier ones.
165 .PP
166 The only exceptions to the above are the \*(L"on\*(R" and \*(L"include\*(R" directives:
167 .IP "on nodename ..." 4
168 .IX Item "on nodename ..."
169 .PD 0
170 .IP "on !nodename ..." 4
171 .IX Item "on !nodename ..."
172 .PD
173 You can prefix any configuration directive with \f(CW\*(C`on\*(C'\fR and a nodename. \s-1GVPE\s0
174 will will only \*(L"execute\*(R" it on the named node, or (if the nodename starts
175 with \f(CW\*(C`!\*(C'\fR) on all nodes except the named one.
176 .Sp
177 Example: set the \s-1MTU\s0 to \f(CW1450\fR everywhere, \f(CW\*(C`loglevel\*(C'\fR to \f(CW\*(C`noise\*(C'\fR on
178 \&\f(CW\*(C`branch1\*(C'\fR, and \f(CW\*(C`connect\*(C'\fR to \f(CW\*(C`ondemand\*(C'\fR everywhere but on branch2.
179 .Sp
180 .Vb 3
181 \& mtu = 1450
182 \& on branch1 loglevel = noise
183 \& on !branch2 connect = ondemand
184 .Ve
185 .IP "include relative-or-absolute-path" 4
186 .IX Item "include relative-or-absolute-path"
187 Reads the specified file (the path must not contain whitespace or \f(CW\*(C`=\*(C'\fR
188 characters) and evaluate all config directives in it as if they were
189 spelled out in place of the \f(CW\*(C`include\*(C'\fR directive.
190 .Sp
191 The path is a printf format string, that is, you must escape any \f(CW\*(C`%\*(C'\fR
192 by doubling it, and you can have a single \f(CW%s\fR inside, which will be
193 replaced by the current nodename.
194 .Sp
195 Relative paths are interpreted relative to the \s-1GVPE\s0 config directory.
196 .Sp
197 Example: include the file \fIlocal.conf\fR in the config directory on every
198 node.
199 .Sp
200 .Vb 1
201 \& include local.conf
202 .Ve
203 .Sp
204 Example: include a file \fIconf/\fRnodename\fI.conf\fR
205 .Sp
206 .Vb 1
207 \& include conf/%s.conf
208 .Ve
209 .SH "ANATOMY OF A CONFIG FILE"
210 .IX Header "ANATOMY OF A CONFIG FILE"
211 Usually, a config file starts with a few global settings (like the \s-1UDP\s0
212 port to listen on), followed by node-specific sections that begin with a
213 \&\f(CW\*(C`node = nickname\*(C'\fR line.
214 .PP
215 Every node that is part of the network must have a section that starts
216 with \f(CW\*(C`node = nickname\*(C'\fR. The number and order of the nodes is important
217 and must be the same on all nodes. It is not uncommon for node sections to
218 be completely empty \- if the default values are right.
219 .PP
220 Node-specific settings can be used at any time. If used before the first
221 node section they will set the default values for all following nodes.
222 .SH "CONFIG VARIABLES"
223 .IX Header "CONFIG VARIABLES"
224 .SS "\s-1GLOBAL\s0 \s-1SETTINGS\s0"
225 .IX Subsection "GLOBAL SETTINGS"
226 Global settings will affect the behaviour of the running gvpe daemon, that
227 is, they are in some sense node-specific (config files can set different
228 values on different nodes using \f(CW\*(C`on\*(C'\fR), but will affect the behaviour of
229 the gvpe daemon and all connections it creates.
230 .IP "dns-forw-host = hostname/ip" 4
231 .IX Item "dns-forw-host = hostname/ip"
232 The \s-1DNS\s0 server to forward \s-1DNS\s0 requests to for the \s-1DNS\s0 tunnel protocol
233 (default: \f(CW127.0.0.1\fR, changing it is highly recommended).
234 .IP "dns-forw-port = port-number" 4
235 .IX Item "dns-forw-port = port-number"
236 The port where the \f(CW\*(C`dns\-forw\-host\*(C'\fR is to be contacted (default: \f(CW53\fR,
237 which is fine in most cases).
238 .IP "dns-case-preserving = yes|true|on | no|false|off" 4
239 .IX Item "dns-case-preserving = yes|true|on | no|false|off"
240 Sets whether the \s-1DNS\s0 transport forwarding server preserves case (\s-1DNS\s0
241 servers have to, but some access systems are even more broken than others)
242 (default: true).
243 .Sp
244 Normally, when the forwarding server changes the case of domain names then
245 \&\s-1GVPE\s0 will automatically set this to false.
246 .IP "dns-max-outstanding = integer-number-of-requests" 4
247 .IX Item "dns-max-outstanding = integer-number-of-requests"
248 The maximum number of outstanding \s-1DNS\s0 transport requests
249 (default: \f(CW100\fR). \s-1GVPE\s0 will never issue more requests then the given
250 limit without receiving replies. In heavily overloaded situations it might
251 help to set this to a low number (e.g. \f(CW3\fR or even \f(CW1\fR) to limit the
252 number of parallel requests.
253 .Sp
254 The default should be working \s-1OK\s0 for most links.
255 .IP "dns-overlap-factor = float" 4
256 .IX Item "dns-overlap-factor = float"
257 The \s-1DNS\s0 transport uses the minimum request latency (\fBmin_latency\fR) seen
258 during a connection as it's timing base. This factor (default: \f(CW0.5\fR,
259 must be > 0) is multiplied by \fBmin_latency\fR to get the maximum sending
260 rate (= minimum send interval), i.e. a factor of \f(CW1\fR means that a new
261 request might be generated every \fBmin_latency\fR seconds, which means on
262 average there should only ever be one outstanding request. A factor of
263 \&\f(CW0.5\fR means that \s-1GVPE\s0 will send requests twice as often as the minimum
264 latency measured.
265 .Sp
266 For congested or picky \s-1DNS\s0 forwarders you could use a value nearer to or
267 exceeding \f(CW1\fR.
268 .Sp
269 The default should be working \s-1OK\s0 for most links.
270 .IP "dns-send-interval = send-interval-in-seconds" 4
271 .IX Item "dns-send-interval = send-interval-in-seconds"
272 The minimum send interval (= maximum rate) that the \s-1DNS\s0 transport will
273 use to send new \s-1DNS\s0 requests. \s-1GVPE\s0 will not exceed this rate even when
274 the latency is very low. The default is \f(CW0.01\fR, which means \s-1GVPE\s0 will
275 not send more than 100 \s-1DNS\s0 requests per connection per second. For
276 high-bandwidth links you could go lower, e.g. to \f(CW0.001\fR or so. For
277 congested or rate-limited links, you might want to go higher, say \f(CW0.1\fR,
278 \&\f(CW0.2\fR or even higher.
279 .Sp
280 The default should be working \s-1OK\s0 for most links.
281 .IP "dns-timeout-factor = float" 4
282 .IX Item "dns-timeout-factor = float"
283 Factor to multiply the \f(CW\*(C`min_latency\*(C'\fR (see \f(CW\*(C`dns\-overlap\-factor\*(C'\fR) by to
284 get request timeouts. The default of \f(CW8\fR means that the \s-1DNS\s0 transport
285 will resend the request when no reply has been received for longer than
286 eight times the minimum (= expected) latency, assuming the request or
287 reply has been lost.
288 .Sp
289 For congested links a higher value might be necessary (e.g. \f(CW30\fR). If
290 the link is very stable lower values (e.g. \f(CW2\fR) might work
291 nicely. Values near or below \f(CW1\fR makes no sense whatsoever.
292 .Sp
293 The default should be working \s-1OK\s0 for most links but will result in low
294 throughput if packet loss is high.
295 .IP "if-up = relative-or-absolute-path" 4
296 .IX Item "if-up = relative-or-absolute-path"
297 Sets the path of a script that should be called immediately after the
298 network interface is initialized (but not necessarily up). The following
299 environment variables are passed to it (the values are just examples).
300 .Sp
301 Variables that have the same value on all nodes:
302 .RS 4
303 .IP "CONFBASE=/etc/gvpe" 4
304 .IX Item "CONFBASE=/etc/gvpe"
305 The configuration base directory.
306 .IP "IFNAME=vpn0" 4
307 .IX Item "IFNAME=vpn0"
308 The network interface to initialize.
309 .IP "IFTYPE=native # or tincd" 4
310 .IX Item "IFTYPE=native # or tincd"
311 .PD 0
312 .IP "IFSUBTYPE=linux # or freebsd, darwin etc.." 4
313 .IX Item "IFSUBTYPE=linux # or freebsd, darwin etc.."
314 .PD
315 The interface type (\f(CW\*(C`native\*(C'\fR or \f(CW\*(C`tincd\*(C'\fR) and the subtype (usually the
316 \&\s-1OS\s0 name in lowercase) that this \s-1GVPE\s0 was configured for. Can be used to
317 select the correct syntax to use for network-related commands.
318 .IP "MTU=1436" 4
319 .IX Item "MTU=1436"
320 The \s-1MTU\s0 to set the interface to. You can use lower values (if done
321 consistently on all nodes), but this is usually either inefficient or
322 simply ineffective.
323 .IP "NODES=5" 4
324 .IX Item "NODES=5"
325 The number of nodes in this \s-1GVPE\s0 network.
326 .RE
327 .RS 4
328 .Sp
329 Variables that are node-specific and with values pertaining to the node
330 running this \s-1GVPE:\s0
331 .IP "IFUPDATA=string" 4
332 .IX Item "IFUPDATA=string"
333 The value of the configuration directive \f(CW\*(C`if\-up\-data\*(C'\fR.
334 .IP "MAC=fe:fd:80:00:00:01" 4
335 .IX Item "MAC=fe:fd:80:00:00:01"
336 The \s-1MAC\s0 address the network interface has to use.
337 .Sp
338 Might be used to initialize interfaces on platforms where \s-1GVPE\s0 does not
339 do this automatically. Please see the \f(CW\*(C`gvpe.osdep(5)\*(C'\fR man page for
340 platform-specific information.
341 .IP "NODENAME=branch1" 4
342 .IX Item "NODENAME=branch1"
343 The nickname of the node.
344 .IP "NODEID=1" 4
345 .IX Item "NODEID=1"
346 The numerical node \s-1ID\s0 of the node running this instance of \s-1GVPE\s0. The first
347 node mentioned in the config file gets \s-1ID\s0 1, the second \s-1ID\s0 2 and so on.
348 .RE
349 .RS 4
350 .Sp
351 In addition, all node-specific variables (except \f(CW\*(C`NODEID\*(C'\fR) will be
352 available with a postfix of \f(CW\*(C`_nodeid\*(C'\fR, which contains the value for that
353 node, e.g. the \f(CW\*(C`MAC_1\*(C'\fR variable contains the \s-1MAC\s0 address of node #1, while
354 the \f(CW\*(C`NODENAME_22\*(C'\fR variable contains the name of node #22.
355 .Sp
356 Here is a simple if-up script:
357 .Sp
358 .Vb 5
359 \& #!/bin/sh
360 \& ip link set $IFNAME up
361 \& [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME
362 \& [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME
363 \& ip route add 10.0.0.0/8 dev $IFNAME
364 .Ve
365 .Sp
366 More complicated examples (using routing to reduce \s-1ARP\s0 traffic) can be
367 found in the \fIetc/\fR subdirectory of the distribution.
368 .RE
369 .IP "ifname = devname" 4
370 .IX Item "ifname = devname"
371 Sets the tun interface name to the given name. The default is OS-specific
372 and most probably something like \f(CW\*(C`tun0\*(C'\fR.
373 .IP "ifpersist = yes|true|on | no|false|off" 4
374 .IX Item "ifpersist = yes|true|on | no|false|off"
375 Should the tun/tap device be made persistent, that is, should the device
376 stay up even when gvpe exits? Some versions of the tunnel device have
377 problems sending packets when gvpe is restarted in persistent mode, so
378 if the connections can be established but you cannot send packets from
379 the local node, try to set this to \f(CW\*(C`off\*(C'\fR and do an ifconfig down on the
380 device.
381 .IP "ip-proto = numerical-ip-protocol" 4
382 .IX Item "ip-proto = numerical-ip-protocol"
383 Sets the protocol number to be used for the rawip protocol. This is a
384 global option because all nodes must use the same protocol, and since
385 there are no port numbers, you cannot easily run more than one gvpe
386 instance using the same protocol, nor can you share the protocol with
387 other programs.
388 .Sp
389 The default is 47 (\s-1GRE\s0), which has a good chance of tunneling
390 through firewalls (but note that gvpe's rawip protocol is not \s-1GRE\s0
391 compatible). Other common choices are 50 (\s-1IPSEC\s0, \s-1ESP\s0), 51 (\s-1IPSEC\s0, \s-1AH\s0), 4
392 (\s-1IPIP\s0 tunnels) or 98 (\s-1ENCAP\s0, rfc1241).
393 .Sp
394 Many versions of Linux seem to have a bug that causes them to reorder
395 packets for some ip protocols (\s-1GRE\s0, \s-1ESP\s0) but not for others (\s-1AH\s0), so
396 choose wisely (that is, use 51, \s-1AH\s0).
397 .IP "http-proxy-host = hostname/ip" 4
398 .IX Item "http-proxy-host = hostname/ip"
399 The \f(CW\*(C`http\-proxy\-*\*(C'\fR family of options are only available if gvpe was
400 compiled with the \f(CW\*(C`\-\-enable\-http\-proxy\*(C'\fR option and enable tunneling of
401 tcp connections through a http proxy server.
402 .Sp
403 \&\f(CW\*(C`http\-proxy\-host\*(C'\fR and \f(CW\*(C`http\-proxy\-port\*(C'\fR should specify the hostname and
404 port number of the proxy server. See \f(CW\*(C`http\-proxy\-loginpw\*(C'\fR if your proxy
405 requires authentication.
406 .Sp
407 Please note that gvpe will still try to resolve all hostnames in the
408 configuration file, so if you are behind a proxy without access to a \s-1DNS\s0
409 server better use numerical \s-1IP\s0 addresses.
410 .Sp
411 To make best use of this option disable all protocols except \s-1TCP\s0 in your
412 config file and make sure your routers (or all other nodes) are listening
413 on a port that the proxy allows (443, https, is a common choice).
414 .Sp
415 If you have a router, connecting to it will suffice. Otherwise \s-1TCP\s0 must be
416 enabled on all nodes.
417 .Sp
418 Example:
419 .Sp
420 .Vb 3
421 \& http\-proxy\-host = proxy.example.com
422 \& http\-proxy\-port = 3128 # 8080 is another common choice
423 \& http\-proxy\-auth = schmorp:grumbeere
424 .Ve
425 .IP "http-proxy-port = proxy-tcp-port" 4
426 .IX Item "http-proxy-port = proxy-tcp-port"
427 The port where your proxy server listens.
428 .IP "http-proxy-auth = login:password" 4
429 .IX Item "http-proxy-auth = login:password"
430 The optional login and password used to authenticate to the proxy server,
431 separated by a literal colon (\f(CW\*(C`:\*(C'\fR). Only basic authentication is
432 currently supported.
433 .IP "keepalive = seconds" 4
434 .IX Item "keepalive = seconds"
435 Sets the keepalive probe interval in seconds (default: \f(CW60\fR). After this
436 many seconds of inactivity the daemon will start to send keepalive probe
437 every 3 seconds until it receives a reply from the other end. If no reply
438 is received within 15 seconds, the peer is considered unreachable and the
439 connection is closed.
440 .IP "loglevel = noise|trace|debug|info|notice|warn|error|critical" 4
441 .IX Item "loglevel = noise|trace|debug|info|notice|warn|error|critical"
442 Set the logging level. Connection established messages are logged at level
443 \&\f(CW\*(C`info\*(C'\fR, notable errors are logged with \f(CW\*(C`error\*(C'\fR. Default is \f(CW\*(C`info\*(C'\fR.
444 .IP "mtu = bytes" 4
445 .IX Item "mtu = bytes"
446 Sets the maximum \s-1MTU\s0 that should be used on outgoing packets (basically
447 the \s-1MTU\s0 of the outgoing interface) The daemon will automatically calculate
448 maximum overhead (e.g. \s-1UDP\s0 header size, encryption blocksize...) and pass
449 this information to the \f(CW\*(C`if\-up\*(C'\fR script.
450 .Sp
451 Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
452 .Sp
453 This value must be the minimum of the \s-1MTU\s0 values of all nodes.
454 .IP "node = nickname" 4
455 .IX Item "node = nickname"
456 Not really a config setting but introduces a node section. The nickname is
457 used to select the right configuration section and must be passed as an
458 argument to the gvpe daemon.
459 .IP "node-up = relative-or-absolute-path" 4
460 .IX Item "node-up = relative-or-absolute-path"
461 Sets a command (default: none) that should be called whenever a connection
462 is established (even on rekeying operations). Note that node\-up/down
463 scripts will be run asynchronously, but execution is serialised, so there
464 will only ever be one such script running.
465 .Sp
466 In addition to all the variables passed to \f(CW\*(C`if\-up\*(C'\fR scripts, the following
467 environment variables will be set (values are just examples):
468 .RS 4
469 .IP "DESTNODE=branch2" 4
470 .IX Item "DESTNODE=branch2"
471 The name of the remote node.
472 .IP "DESTID=2" 4
473 .IX Item "DESTID=2"
474 The node id of the remote node.
475 .IP "DESTSI=rawip/88.99.77.55:0" 4
476 .IX Item "DESTSI=rawip/88.99.77.55:0"
477 The \*(L"socket info\*(R" of the target node, protocol dependent but usually in
478 the format protocol/ip:port.
479 .IP "DESTIP=188.13.66.8" 4
480 .IX Item "DESTIP=188.13.66.8"
481 The numerical \s-1IP\s0 address of the remote node (gvpe accepts connections from
482 everywhere, as long as the other node can authenticate itself).
483 .IP "DESTPORT=655 # deprecated" 4
484 .IX Item "DESTPORT=655 # deprecated"
485 The protocol port used by the other side, if applicable.
486 .IP "STATE=up" 4
487 .IX Item "STATE=up"
488 Node-up scripts get called with STATE=up, node-change scripts get called
489 with STATE=change and node-down scripts get called with STATE=down.
490 .RE
491 .RS 4
492 .Sp
493 Here is a nontrivial example that uses nsupdate to update the name => ip
494 mapping in some \s-1DNS\s0 zone:
495 .Sp
496 .Vb 6
497 \& #!/bin/sh
498 \& {
499 \& echo update delete $DESTNODE.lowttl.example.net. a
500 \& echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP
501 \& echo
502 \& } | nsupdate \-d \-k $CONFBASE:key.example.net.
503 .Ve
504 .RE
505 .IP "node-change = relative-or-absolute-path" 4
506 .IX Item "node-change = relative-or-absolute-path"
507 Same as \f(CW\*(C`node\-change\*(C'\fR, but gets called whenever something about a
508 connection changes (such as the source \s-1IP\s0 address).
509 .IP "node-down = relative-or-absolute-path" 4
510 .IX Item "node-down = relative-or-absolute-path"
511 Same as \f(CW\*(C`node\-up\*(C'\fR, but gets called whenever a connection is lost.
512 .IP "pid-file = path" 4
513 .IX Item "pid-file = path"
514 The path to the pid file to check and create
515 (default: \f(CW\*(C`LOCALSTATEDIR/run/gvpe.pid\*(C'\fR).
516 .IP "private-key = relative-path-to-key" 4
517 .IX Item "private-key = relative-path-to-key"
518 Sets the path (relative to the config directory) to the private key
519 (default: \f(CW\*(C`hostkey\*(C'\fR). This is a printf format string so every \f(CW\*(C`%\*(C'\fR must
520 be doubled. A single \f(CW%s\fR is replaced by the hostname, so you could
521 use paths like \f(CW\*(C`hostkeys/%s\*(C'\fR to fetch the files at the location where
522 \&\f(CW\*(C`gvpectrl\*(C'\fR puts them.
523 .Sp
524 Since only the private key file of the current node is used and the
525 private key file should be kept secret per-node to avoid spoofing, it is
526 not recommended to use this feature.
527 .IP "rekey = seconds" 4
528 .IX Item "rekey = seconds"
529 Sets the rekeying interval in seconds (default: \f(CW3600\fR). Connections are
530 reestablished every \f(CW\*(C`rekey\*(C'\fR seconds, making them use a new encryption
531 key.
532 .IP "nfmark = integer" 4
533 .IX Item "nfmark = integer"
534 This advanced option, when set to a nonzero value (default: \f(CW0\fR), tries
535 to set the netfilter mark (or fwmark) value on all sockets gvpe uses to
536 send packets.
537 .Sp
538 This can be used to make gvpe use a different set of routing rules. For
539 example, on GNU/Linux, the \f(CW\*(C`if\-up\*(C'\fR could set \f(CW\*(C`nfmark\*(C'\fR to 1000 and then
540 put all routing rules into table \f(CW99\fR and then use an ip rule to make
541 gvpe traffic avoid that routing table, in effect routing normal traffic
542 via gvpe and gvpe traffic via the normal system routing tables:
543 .Sp
544 .Vb 1
545 \& ip rule add not fwmark 1000 lookup 99
546 .Ve
547 .SS "\s-1NODE\s0 \s-1SPECIFIC\s0 \s-1SETTINGS\s0"
548 .IX Subsection "NODE SPECIFIC SETTINGS"
549 The following settings are node-specific, that is, every node can have
550 different settings, even within the same gvpe instance. Settings that are
551 set before the first node section set the defaults, settings that are
552 set within a node section only apply to the given node.
553 .IP "allow-direct = nodename" 4
554 .IX Item "allow-direct = nodename"
555 Allow direct connections to this node. See \f(CW\*(C`deny\-direct\*(C'\fR for more info.
556 .IP "compress = yes|true|on | no|false|off" 4
557 .IX Item "compress = yes|true|on | no|false|off"
558 For the current node, this specified whether it will accept compressed
559 packets, and for all other nodes, this specifies whether to try to
560 compress data packets sent to this node (default: \f(CW\*(C`yes\*(C'\fR). Compression is
561 really cheap even on slow computers, has no size overhead at all and will
562 only be used when the other side supports compression, so enabling this is
563 often a good idea.
564 .IP "connect = ondemand | never | always | disabled" 4
565 .IX Item "connect = ondemand | never | always | disabled"
566 Sets the connect mode (default: \f(CW\*(C`always\*(C'\fR). It can be \f(CW\*(C`always\*(C'\fR (always
567 try to establish and keep a connection to the given node), \f(CW\*(C`never\*(C'\fR
568 (never initiate a connection to the given host, but accept connections),
569 \&\f(CW\*(C`ondemand\*(C'\fR (try to establish a connection when there are outstanding
570 packets in the queue and take it down after the keepalive interval) or
571 \&\f(CW\*(C`disabled\*(C'\fR (node is bad, don't talk to it).
572 .Sp
573 Routers will automatically be forced to \f(CW\*(C`always\*(C'\fR unless they are
574 \&\f(CW\*(C`disabled\*(C'\fR, to ensure all nodes can talk to each other.
575 .IP "deny-direct = nodename | *" 4
576 .IX Item "deny-direct = nodename | *"
577 Deny direct connections to the specified node (or all nodes when \f(CW\*(C`*\*(C'\fR
578 is given). Only one node can be specified, but you can use multiple
579 \&\f(CW\*(C`allow\-direct\*(C'\fR and \f(CW\*(C`deny\-direct\*(C'\fR statements. This only makes sense in
580 networks with routers, as routers are required for indirect connections.
581 .Sp
582 Sometimes, a node cannot reach some other nodes for reasons of network
583 connectivity. For example, a node behind a firewall that only allows
584 connections to/from a single other node in the network. In this case one
585 should specify \f(CW\*(C`deny\-direct = *\*(C'\fR and \f(CW\*(C`allow\-direct = othernodename\*(C'\fR (the other
586 node \fImust\fR be a router for this to work).
587 .Sp
588 The algorithm to check whether a connection may be direct is as follows:
589 .Sp
590 1. Other node mentioned in an \f(CW\*(C`allow\-direct\*(C'\fR? If yes, allow the connection.
591 .Sp
592 2. Other node mentioned in a \f(CW\*(C`deny\-direct\*(C'\fR? If yes, deny direct connections.
593 .Sp
594 3. Allow the connection.
595 .Sp
596 That is, \f(CW\*(C`allow\-direct\*(C'\fR takes precedence over \f(CW\*(C`deny\-direct\*(C'\fR.
597 .Sp
598 The check is done in both directions, i.e. both nodes must allow a direct
599 connection before one is attempted, so you only need to specify connect
600 limitations on one node.
601 .IP "dns-domain = domain-suffix" 4
602 .IX Item "dns-domain = domain-suffix"
603 The \s-1DNS\s0 domain suffix that points to the \s-1DNS\s0 tunnel server for this node.
604 .Sp
605 The domain must point to a \s-1NS\s0 record that points to the \fIdns-hostname\fR,
606 i.e.
607 .Sp
608 .Vb 2
609 \& dns\-domainname = tunnel.example.net
610 \& dns\-hostname = tunnel\-server.example.net
611 .Ve
612 .Sp
613 Corresponds to the following \s-1DNS\s0 entries in the \f(CW\*(C`example.net\*(C'\fR domain:
614 .Sp
615 .Vb 2
616 \& tunnel.example.net. NS tunnel\-server.example.net.
617 \& tunnel\-server.example.net. A 13.13.13.13
618 .Ve
619 .IP "dns-hostname = hostname/ip" 4
620 .IX Item "dns-hostname = hostname/ip"
621 The address to bind the \s-1DNS\s0 tunnel socket to, similar to the \f(CW\*(C`hostname\*(C'\fR,
622 but for the \s-1DNS\s0 tunnel protocol only. Default: \f(CW0.0.0.0\fR, but that might
623 change.
624 .IP "dns-port = port-number" 4
625 .IX Item "dns-port = port-number"
626 The port to bind the \s-1DNS\s0 tunnel socket to. Must be \f(CW53\fR on \s-1DNS\s0 tunnel servers.
627 .IP "enable-dns = yes|true|on | no|false|off" 4
628 .IX Item "enable-dns = yes|true|on | no|false|off"
629 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1DNS\s0 transport
630 protocol. Avoid this protocol if you can.
631 .Sp
632 Enable the \s-1DNS\s0 tunneling protocol on this node, either as server or as
633 client. Support for this transport protocol is only available when gvpe
634 was compiled using the \f(CW\*(C`\-\-enable\-dns\*(C'\fR option.
635 .IP "enable-icmp = yes|true|on | no|false|off" 4
636 .IX Item "enable-icmp = yes|true|on | no|false|off"
637 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1ICMP\s0 transport protocol.
638 .Sp
639 Enable the \s-1ICMP\s0 transport using \s-1ICMP\s0 packets of type \f(CW\*(C`icmp\-type\*(C'\fR on this
640 node.
641 .IP "enable-rawip = yes|true|on | no|false|off" 4
642 .IX Item "enable-rawip = yes|true|on | no|false|off"
643 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1RAW\s0 \s-1IP\s0 transport protocol.
644 .Sp
645 Enable the \s-1RAW\s0 IPv4 transport using the \f(CW\*(C`ip\-proto\*(C'\fR protocol
646 (default: \f(CW\*(C`no\*(C'\fR).
647 .IP "enable-tcp = yes|true|on | no|false|off" 4
648 .IX Item "enable-tcp = yes|true|on | no|false|off"
649 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1TCP\s0 transport protocol.
650 .Sp
651 Enable the TCPv4 transport using the \f(CW\*(C`tcp\-port\*(C'\fR port
652 (default: \f(CW\*(C`no\*(C'\fR). Support for this transport protocol is only available
653 when gvpe was compiled using the \f(CW\*(C`\-\-enable\-tcp\*(C'\fR option.
654 .IP "enable-udp = yes|true|on | no|false|off" 4
655 .IX Item "enable-udp = yes|true|on | no|false|off"
656 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1UDP\s0 transport protocol.
657 .Sp
658 Enable the UDPv4 transport using the \f(CW\*(C`udp\-port\*(C'\fR port (default: \f(CW\*(C`no\*(C'\fR).
659 .IP "hostname = hostname | ip [can not be defaulted]" 4
660 .IX Item "hostname = hostname | ip [can not be defaulted]"
661 Forces the address of this node to be set to the given \s-1DNS\s0 hostname or \s-1IP\s0
662 address. It will be resolved before each connect request, so dyndns should
663 work fine. If this setting is not specified and a router is available,
664 then the router will be queried for the address of this node. Otherwise,
665 the connection attempt will fail.
666 .Sp
667 Note that \s-1DNS\s0 resolving is done synchronously, pausing the daemon. If that
668 is an issue you need to specify \s-1IP\s0 addresses.
669 .IP "icmp-type = integer" 4
670 .IX Item "icmp-type = integer"
671 Sets the type value to be used for outgoing (and incoming) packets sent
672 via the \s-1ICMP\s0 transport.
673 .Sp
674 The default is \f(CW0\fR (which is \f(CW\*(C`echo\-reply\*(C'\fR, also known as
675 \&\*(L"ping-reply\*(R"). Other useful values include \f(CW8\fR (\f(CW\*(C`echo\-request\*(C'\fR, a.k.a.
676 \&\*(L"ping\*(R") and \f(CW11\fR (\f(CW\*(C`time\-exceeded\*(C'\fR), but any 8\-bit value can be used.
677 .IP "if-up-data = value" 4
678 .IX Item "if-up-data = value"
679 The value specified using this directive will be passed to the \f(CW\*(C`if\-up\*(C'\fR
680 script in the environment variable \f(CW\*(C`IFUPDATA\*(C'\fR.
681 .IP "inherit-tos = yes|true|on | no|false|off" 4
682 .IX Item "inherit-tos = yes|true|on | no|false|off"
683 Whether to inherit the \s-1TOS\s0 settings of packets sent to the tunnel when
684 sending packets to this node (default: \f(CW\*(C`yes\*(C'\fR). If set to \f(CW\*(C`yes\*(C'\fR then
685 outgoing tunnel packets will have the same \s-1TOS\s0 setting as the packets sent
686 to the tunnel device, which is usually what you want.
687 .IP "max-retry = positive-number" 4
688 .IX Item "max-retry = positive-number"
689 The maximum interval in seconds (default: \f(CW3600\fR, one hour) between
690 retries to establish a connection to this node. When a connection cannot
691 be established, gvpe uses exponential back-off capped at this value. It's
692 sometimes useful to set this to a much lower value (e.g. \f(CW120\fR) on
693 connections to routers that usually are stable but sometimes are down, to
694 assure quick reconnections even after longer downtimes.
695 .IP "max-ttl = seconds" 4
696 .IX Item "max-ttl = seconds"
697 Expire packets that couldn't be sent after this many seconds
698 (default: \f(CW60\fR). Gvpe will normally queue packets for a node without an
699 active connection, in the hope of establishing a connection soon. This
700 value specifies the maximum lifetime a packet will stay in the queue, if a
701 packet gets older, it will be thrown away.
702 .IP "max-queue = positive\-number>=1" 4
703 .IX Item "max-queue = positive-number>=1"
704 The maximum number of packets that will be queued (default: \f(CW512\fR)
705 for this node. If more packets are sent then earlier packets will be
706 expired. See \f(CW\*(C`max\-ttl\*(C'\fR, above.
707 .IP "router-priority = 0 | 1 | positive\-number>=2" 4
708 .IX Item "router-priority = 0 | 1 | positive-number>=2"
709 Sets the router priority of the given node (default: \f(CW0\fR, disabled).
710 .Sp
711 If some node tries to connect to another node but it doesn't have a
712 hostname, it asks a router node for it's \s-1IP\s0 address. The router node
713 chosen is the one with the highest priority larger than \f(CW1\fR that is
714 currently reachable. This is called a \fImediated\fR connection, as the
715 connection itself will still be direct, but it uses another node to
716 mediate between the two nodes.
717 .Sp
718 The value \f(CW0\fR disables routing, that means if the node receives a packet
719 not for itself it will not forward it but instead drop it.
720 .Sp
721 The special value \f(CW1\fR allows other hosts to route through the router
722 host, but they will never route through it by default (i.e. the config
723 file of another node needs to specify a router priority higher than one
724 to choose such a node for routing).
725 .Sp
726 The idea behind this is that some hosts can, if required, bump the
727 \&\f(CW\*(C`router\-priority\*(C'\fR setting to higher than \f(CW1\fR in their local config to
728 route through specific hosts. If \f(CW\*(C`router\-priority\*(C'\fR is \f(CW0\fR, then routing
729 will be refused, so \f(CW1\fR serves as a \*(L"enable, but do not use by default\*(R"
730 switch.
731 .Sp
732 Nodes with \f(CW\*(C`router\-priority\*(C'\fR set to \f(CW2\fR or higher will always be forced
733 to \f(CW\*(C`connect\*(C'\fR = \f(CW\*(C`always\*(C'\fR (unless they are \f(CW\*(C`disabled\*(C'\fR).
734 .IP "tcp-port = port-number" 4
735 .IX Item "tcp-port = port-number"
736 Similar to \f(CW\*(C`udp\-port\*(C'\fR (default: \f(CW655\fR), but sets the \s-1TCP\s0 port number.
737 .IP "udp-port = port-number" 4
738 .IX Item "udp-port = port-number"
739 Sets the port number used by the \s-1UDP\s0 protocol (default: \f(CW655\fR, not
740 officially assigned by \s-1IANA\s0!).
741 .SH "CONFIG DIRECTORY LAYOUT"
742 .IX Header "CONFIG DIRECTORY LAYOUT"
743 The default (or recommended) directory layout for the config directory is:
744 .IP "gvpe.conf" 4
745 .IX Item "gvpe.conf"
746 The config file.
747 .IP "if-up" 4
748 .IX Item "if-up"
749 The if-up script
750 .IP "node-up, node-down" 4
751 .IX Item "node-up, node-down"
752 If used the node up or node-down scripts.
753 .IP "hostkey" 4
754 .IX Item "hostkey"
755 The private key (taken from \f(CW\*(C`hostkeys/nodename\*(C'\fR) of the current host.
756 .IP "pubkey/nodename" 4
757 .IX Item "pubkey/nodename"
758 The public keys of the other nodes, one file per node.
759 .SH "SEE ALSO"
760 .IX Header "SEE ALSO"
761 \&\fIgvpe\fR\|(5), \fIgvpe\fR\|(8), \fIgvpectrl\fR\|(8).
762 .SH "AUTHOR"
763 .IX Header "AUTHOR"
764 Marc Lehmann <gvpe@schmorp.de>