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Revision: 1.26
Committed: Thu Dec 2 07:15:14 2010 UTC (13 years, 5 months ago) by root
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# Content
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124 .\" ========================================================================
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126 .IX Title "GVPE.CONF 5"
127 .TH GVPE.CONF 5 "2010-09-10" "2.22" "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 The only exception to the above is the \*(L"on\*(R" directive that can prefix any
164 \&\f(CW\*(C`name = value\*(C'\fR setting and will only \*(L"execute\*(R" it on the named node, or
165 (if the nodename starts with \*(L"!\*(R") on all nodes except the named one.
166 .PP
167 For example, set the \s-1MTU\s0 to \f(CW1450\fR everywhere, loglevel to \f(CW\*(C`noise\*(C'\fR on
168 branch1, and connect to \f(CW\*(C`ondemand\*(C'\fR everywhere but on branch2:
169 .PP
170 .Vb 3
171 \& mtu = 1450
172 \& on branch1 loglevel = noise
173 \& on !branch2 connect = ondemand
174 .Ve
175 .PP
176 All settings are applied \*(L"in order\*(R", that is, later settings of the same
177 variable overwrite earlier ones.
178 .SH "ANATOMY OF A CONFIG FILE"
179 .IX Header "ANATOMY OF A CONFIG FILE"
180 Usually, a config file starts with a few global settings (like the \s-1UDP\s0
181 port to listen on), followed by node-specific sections that begin with a
182 \&\f(CW\*(C`node = nickname\*(C'\fR line.
183 .PP
184 Every node that is part of the network must have a section that starts
185 with \f(CW\*(C`node = nickname\*(C'\fR. The number and order of the nodes is important
186 and must be the same on all nodes. It is not uncommon for node sections to
187 be completely empty \- if the default values are right.
188 .PP
189 Node-specific settings can be used at any time. If used before the first
190 node section they will set the default values for all following nodes.
191 .SH "CONFIG VARIABLES"
192 .IX Header "CONFIG VARIABLES"
193 .SS "\s-1GLOBAL\s0 \s-1SETTINGS\s0"
194 .IX Subsection "GLOBAL SETTINGS"
195 Global settings will affect the behaviour of the running gvpe daemon, that
196 is, they are in some sense node-specific (config files can set different
197 values on different nodes using \f(CW\*(C`on\*(C'\fR), but will affect the behaviour of
198 the gvpe daemon and all connections it creates.
199 .IP "dns-forw-host = hostname/ip" 4
200 .IX Item "dns-forw-host = hostname/ip"
201 The \s-1DNS\s0 server to forward \s-1DNS\s0 requests to for the \s-1DNS\s0 tunnel protocol
202 (default: \f(CW127.0.0.1\fR, changing it is highly recommended).
203 .IP "dns-forw-port = port-number" 4
204 .IX Item "dns-forw-port = port-number"
205 The port where the \f(CW\*(C`dns\-forw\-host\*(C'\fR is to be contacted (default: \f(CW53\fR,
206 which is fine in most cases).
207 .IP "dns-max-outstanding = integer-number-of-requests" 4
208 .IX Item "dns-max-outstanding = integer-number-of-requests"
209 The maximum number of outstanding \s-1DNS\s0 transport requests
210 (default: \f(CW100\fR). \s-1GVPE\s0 will never issue more requests then the given
211 limit without receiving replies. In heavily overloaded situations it might
212 help to set this to a low number (e.g. \f(CW3\fR or even \f(CW1\fR) to limit the
213 number of parallel requests.
214 .Sp
215 The default should be working \s-1OK\s0 for most links.
216 .IP "dns-overlap-factor = float" 4
217 .IX Item "dns-overlap-factor = float"
218 The \s-1DNS\s0 transport uses the minimum request latency (\fBmin_latency\fR) seen
219 during a connection as it's timing base. This factor (default: \f(CW0.5\fR,
220 must be > 0) is multiplied by \fBmin_latency\fR to get the maximum sending
221 rate (= minimum send interval), i.e. a factor of \f(CW1\fR means that a new
222 request might be generated every \fBmin_latency\fR seconds, which means on
223 average there should only ever be one outstanding request. A factor of
224 \&\f(CW0.5\fR means that \s-1GVPE\s0 will send requests twice as often as the minimum
225 latency measured.
226 .Sp
227 For congested or picky \s-1DNS\s0 forwarders you could use a value nearer to or
228 exceeding \f(CW1\fR.
229 .Sp
230 The default should be working \s-1OK\s0 for most links.
231 .IP "dns-send-interval = send-interval-in-seconds" 4
232 .IX Item "dns-send-interval = send-interval-in-seconds"
233 The minimum send interval (= maximum rate) that the \s-1DNS\s0 transport will
234 use to send new \s-1DNS\s0 requests. \s-1GVPE\s0 will not exceed this rate even when
235 the latency is very low. The default is \f(CW0.01\fR, which means \s-1GVPE\s0 will
236 not send more than 100 \s-1DNS\s0 requests per connection per second. For
237 high-bandwidth links you could go lower, e.g. to \f(CW0.001\fR or so. For
238 congested or rate-limited links, you might want to go higher, say \f(CW0.1\fR,
239 \&\f(CW0.2\fR or even higher.
240 .Sp
241 The default should be working \s-1OK\s0 for most links.
242 .IP "dns-timeout-factor = float" 4
243 .IX Item "dns-timeout-factor = float"
244 Factor to multiply the \f(CW\*(C`min_latency\*(C'\fR (see \f(CW\*(C`dns\-overlap\-factor\*(C'\fR) by to
245 get request timeouts. The default of \f(CW8\fR means that the \s-1DNS\s0 transport
246 will resend the request when no reply has been received for longer than
247 eight times the minimum (= expected) latency, assuming the request or
248 reply has been lost.
249 .Sp
250 For congested links a higher value might be necessary (e.g. \f(CW30\fR). If
251 the link is very stable lower values (e.g. \f(CW2\fR) might work
252 nicely. Values near or below \f(CW1\fR makes no sense whatsoever.
253 .Sp
254 The default should be working \s-1OK\s0 for most links but will result in low
255 throughput if packet loss is high.
256 .IP "if-up = relative-or-absolute-path" 4
257 .IX Item "if-up = relative-or-absolute-path"
258 Sets the path of a script that should be called immediately after the
259 network interface is initialized (but not necessarily up). The following
260 environment variables are passed to it (the values are just examples).
261 .Sp
262 Variables that have the same value on all nodes:
263 .RS 4
264 .IP "CONFBASE=/etc/gvpe" 4
265 .IX Item "CONFBASE=/etc/gvpe"
266 The configuration base directory.
267 .IP "IFNAME=vpn0" 4
268 .IX Item "IFNAME=vpn0"
269 The network interface to initialize.
270 .IP "IFTYPE=native # or tincd" 4
271 .IX Item "IFTYPE=native # or tincd"
272 .PD 0
273 .IP "IFSUBTYPE=linux # or freebsd, darwin etc.." 4
274 .IX Item "IFSUBTYPE=linux # or freebsd, darwin etc.."
275 .PD
276 The interface type (\f(CW\*(C`native\*(C'\fR or \f(CW\*(C`tincd\*(C'\fR) and the subtype (usually the
277 \&\s-1OS\s0 name in lowercase) that this \s-1GVPE\s0 was configured for. Can be used to
278 select the correct syntax to use for network-related commands.
279 .IP "MTU=1436" 4
280 .IX Item "MTU=1436"
281 The \s-1MTU\s0 to set the interface to. You can use lower values (if done
282 consistently on all nodes), but this is usually either inefficient or
283 simply ineffective.
284 .IP "NODES=5" 4
285 .IX Item "NODES=5"
286 The number of nodes in this \s-1GVPE\s0 network.
287 .RE
288 .RS 4
289 .Sp
290 Variables that are node-specific and with values pertaining to the node
291 running this \s-1GVPE:\s0
292 .IP "IFUPDATA=string" 4
293 .IX Item "IFUPDATA=string"
294 The value of the configuration directive \f(CW\*(C`if\-up\-data\*(C'\fR.
295 .IP "MAC=fe:fd:80:00:00:01" 4
296 .IX Item "MAC=fe:fd:80:00:00:01"
297 The \s-1MAC\s0 address the network interface has to use.
298 .Sp
299 Might be used to initialize interfaces on platforms where \s-1GVPE\s0 does not
300 do this automatically. Please see the \f(CW\*(C`gvpe.osdep(5)\*(C'\fR man page for
301 platform-specific information.
302 .IP "NODENAME=branch1" 4
303 .IX Item "NODENAME=branch1"
304 The nickname of the node.
305 .IP "NODEID=1" 4
306 .IX Item "NODEID=1"
307 The numerical node \s-1ID\s0 of the node running this instance of \s-1GVPE\s0. The first
308 node mentioned in the config file gets \s-1ID\s0 1, the second \s-1ID\s0 2 and so on.
309 .RE
310 .RS 4
311 .Sp
312 In addition, all node-specific variables (except \f(CW\*(C`NODEID\*(C'\fR) will be
313 available with a postfix of \f(CW\*(C`_nodeid\*(C'\fR, which contains the value for that
314 node, e.g. the \f(CW\*(C`MAC_1\*(C'\fR variable contains the \s-1MAC\s0 address of node #1, while
315 the \f(CW\*(C`NODENAME_22\*(C'\fR variable contains the name of node #22.
316 .Sp
317 Here is a simple if-up script:
318 .Sp
319 .Vb 5
320 \& #!/bin/sh
321 \& ip link set $IFNAME up
322 \& [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME
323 \& [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME
324 \& ip route add 10.0.0.0/8 dev $IFNAME
325 .Ve
326 .Sp
327 More complicated examples (using routing to reduce \s-1ARP\s0 traffic) can be
328 found in the \fIetc/\fR subdirectory of the distribution.
329 .RE
330 .IP "ifname = devname" 4
331 .IX Item "ifname = devname"
332 Sets the tun interface name to the given name. The default is OS-specific
333 and most probably something like \f(CW\*(C`tun0\*(C'\fR.
334 .IP "ifpersist = yes|true|on | no|false|off" 4
335 .IX Item "ifpersist = yes|true|on | no|false|off"
336 Should the tun/tap device be made persistent, that is, should the device
337 stay up even when gvpe exits? Some versions of the tunnel device have
338 problems sending packets when gvpe is restarted in persistent mode, so
339 if the connections can be established but you cannot send packets from
340 the local node, try to set this to \f(CW\*(C`off\*(C'\fR and do an ifconfig down on the
341 device.
342 .IP "ip-proto = numerical-ip-protocol" 4
343 .IX Item "ip-proto = numerical-ip-protocol"
344 Sets the protocol number to be used for the rawip protocol. This is a
345 global option because all nodes must use the same protocol, and since
346 there are no port numbers, you cannot easily run more than one gvpe
347 instance using the same protocol, nor can you share the protocol with
348 other programs.
349 .Sp
350 The default is 47 (\s-1GRE\s0), which has a good chance of tunneling
351 through firewalls (but note that gvpe's rawip protocol is not \s-1GRE\s0
352 compatible). Other common choices are 50 (\s-1IPSEC\s0, \s-1ESP\s0), 51 (\s-1IPSEC\s0, \s-1AH\s0), 4
353 (\s-1IPIP\s0 tunnels) or 98 (\s-1ENCAP\s0, rfc1241).
354 .Sp
355 Many versions of Linux seem to have a bug that causes them to reorder
356 packets for some ip protocols (\s-1GRE\s0, \s-1ESP\s0) but not for others (\s-1AH\s0), so
357 choose wisely (that is, use 51, \s-1AH\s0).
358 .IP "http-proxy-host = hostname/ip" 4
359 .IX Item "http-proxy-host = hostname/ip"
360 The \f(CW\*(C`http\-proxy\-*\*(C'\fR family of options are only available if gvpe was
361 compiled with the \f(CW\*(C`\-\-enable\-http\-proxy\*(C'\fR option and enable tunneling of
362 tcp connections through a http proxy server.
363 .Sp
364 \&\f(CW\*(C`http\-proxy\-host\*(C'\fR and \f(CW\*(C`http\-proxy\-port\*(C'\fR should specify the hostname and
365 port number of the proxy server. See \f(CW\*(C`http\-proxy\-loginpw\*(C'\fR if your proxy
366 requires authentication.
367 .Sp
368 Please note that gvpe will still try to resolve all hostnames in the
369 configuration file, so if you are behind a proxy without access to a \s-1DNS\s0
370 server better use numerical \s-1IP\s0 addresses.
371 .Sp
372 To make best use of this option disable all protocols except \s-1TCP\s0 in your
373 config file and make sure your routers (or all other nodes) are listening
374 on a port that the proxy allows (443, https, is a common choice).
375 .Sp
376 If you have a router, connecting to it will suffice. Otherwise \s-1TCP\s0 must be
377 enabled on all nodes.
378 .Sp
379 Example:
380 .Sp
381 .Vb 3
382 \& http\-proxy\-host = proxy.example.com
383 \& http\-proxy\-port = 3128 # 8080 is another common choice
384 \& http\-proxy\-auth = schmorp:grumbeere
385 .Ve
386 .IP "http-proxy-port = proxy-tcp-port" 4
387 .IX Item "http-proxy-port = proxy-tcp-port"
388 The port where your proxy server listens.
389 .IP "http-proxy-auth = login:password" 4
390 .IX Item "http-proxy-auth = login:password"
391 The optional login and password used to authenticate to the proxy server,
392 separated by a literal colon (\f(CW\*(C`:\*(C'\fR). Only basic authentication is
393 currently supported.
394 .IP "keepalive = seconds" 4
395 .IX Item "keepalive = seconds"
396 Sets the keepalive probe interval in seconds (default: \f(CW60\fR). After this
397 many seconds of inactivity the daemon will start to send keepalive probe
398 every 3 seconds until it receives a reply from the other end. If no reply
399 is received within 15 seconds, the peer is considered unreachable and the
400 connection is closed.
401 .IP "loglevel = noise|trace|debug|info|notice|warn|error|critical" 4
402 .IX Item "loglevel = noise|trace|debug|info|notice|warn|error|critical"
403 Set the logging level. Connection established messages are logged at level
404 \&\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.
405 .IP "mtu = bytes" 4
406 .IX Item "mtu = bytes"
407 Sets the maximum \s-1MTU\s0 that should be used on outgoing packets (basically
408 the \s-1MTU\s0 of the outgoing interface) The daemon will automatically calculate
409 maximum overhead (e.g. \s-1UDP\s0 header size, encryption blocksize...) and pass
410 this information to the \f(CW\*(C`if\-up\*(C'\fR script.
411 .Sp
412 Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
413 .Sp
414 This value must be the minimum of the \s-1MTU\s0 values of all nodes.
415 .IP "node = nickname" 4
416 .IX Item "node = nickname"
417 Not really a config setting but introduces a node section. The nickname is
418 used to select the right configuration section and must be passed as an
419 argument to the gvpe daemon.
420 .IP "node-up = relative-or-absolute-path" 4
421 .IX Item "node-up = relative-or-absolute-path"
422 Sets a command (default: none) that should be called whenever a connection
423 is established (even on rekeying operations). Note that node\-up/down
424 scripts will be run asynchronously, but execution is serialised, so there
425 will only ever be one such script running.
426 .Sp
427 In addition to all the variables passed to \f(CW\*(C`if\-up\*(C'\fR scripts, the following
428 environment variables will be set (values are just examples):
429 .RS 4
430 .IP "DESTNODE=branch2" 4
431 .IX Item "DESTNODE=branch2"
432 The name of the remote node.
433 .IP "DESTID=2" 4
434 .IX Item "DESTID=2"
435 The node id of the remote node.
436 .IP "DESTSI=rawip/88.99.77.55:0" 4
437 .IX Item "DESTSI=rawip/88.99.77.55:0"
438 The \*(L"socket info\*(R" of the target node, protocol dependent but usually in
439 the format protocol/ip:port.
440 .IP "DESTIP=188.13.66.8" 4
441 .IX Item "DESTIP=188.13.66.8"
442 The numerical \s-1IP\s0 address of the remote node (gvpe accepts connections from
443 everywhere, as long as the other node can authenticate itself).
444 .IP "DESTPORT=655 # deprecated" 4
445 .IX Item "DESTPORT=655 # deprecated"
446 The protocol port used by the other side, if applicable.
447 .IP "STATE=up" 4
448 .IX Item "STATE=up"
449 Node-up scripts get called with STATE=up, node-change scripts get called
450 with STATE=change and node-down scripts get called with STATE=down.
451 .RE
452 .RS 4
453 .Sp
454 Here is a nontrivial example that uses nsupdate to update the name => ip
455 mapping in some \s-1DNS\s0 zone:
456 .Sp
457 .Vb 6
458 \& #!/bin/sh
459 \& {
460 \& echo update delete $DESTNODE.lowttl.example.net. a
461 \& echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP
462 \& echo
463 \& } | nsupdate \-d \-k $CONFBASE:key.example.net.
464 .Ve
465 .RE
466 .IP "node-change = relative-or-absolute-path" 4
467 .IX Item "node-change = relative-or-absolute-path"
468 Same as \f(CW\*(C`node\-change\*(C'\fR, but gets called whenever something about a
469 connection changes (such as the source \s-1IP\s0 address).
470 .IP "node-down = relative-or-absolute-path" 4
471 .IX Item "node-down = relative-or-absolute-path"
472 Same as \f(CW\*(C`node\-up\*(C'\fR, but gets called whenever a connection is lost.
473 .IP "pid-file = path" 4
474 .IX Item "pid-file = path"
475 The path to the pid file to check and create
476 (default: \f(CW\*(C`LOCALSTATEDIR/run/gvpe.pid\*(C'\fR).
477 .IP "private-key = relative-path-to-key" 4
478 .IX Item "private-key = relative-path-to-key"
479 Sets the path (relative to the config directory) to the private key
480 (default: \f(CW\*(C`hostkey\*(C'\fR). This is a printf format string so every \f(CW\*(C`%\*(C'\fR must
481 be doubled. A single \f(CW%s\fR is replaced by the hostname, so you could
482 use paths like \f(CW\*(C`hostkeys/%s\*(C'\fR to fetch the files at the location where
483 \&\f(CW\*(C`gvpectrl\*(C'\fR puts them.
484 .Sp
485 Since only the private key file of the current node is used and the
486 private key file should be kept secret per-node to avoid spoofing, it is
487 not recommended to use this feature.
488 .IP "rekey = seconds" 4
489 .IX Item "rekey = seconds"
490 Sets the rekeying interval in seconds (default: \f(CW3600\fR). Connections are
491 reestablished every \f(CW\*(C`rekey\*(C'\fR seconds, making them use a new encryption
492 key.
493 .IP "nfmark = integer" 4
494 .IX Item "nfmark = integer"
495 This advanced option, when set to a nonzero value (default: \f(CW0\fR), tries
496 to set the netfilter mark (or fwmark) value on all sockets gvpe uses to
497 send packets.
498 .Sp
499 This can be used to make gvpe use a different set of routing rules. For
500 example, on GNU/Linux, the \f(CW\*(C`if\-up\*(C'\fR could set \f(CW\*(C`nfmark\*(C'\fR to 1000 and then
501 put all routing rules into table \f(CW99\fR and then use an ip rule to make
502 gvpe traffic avoid that routing table, in effect routing normal traffic
503 via gvpe and gvpe traffic via the normal system routing tables:
504 .Sp
505 .Vb 1
506 \& ip rule add not fwmark 1000 lookup 99
507 .Ve
508 .SS "\s-1NODE\s0 \s-1SPECIFIC\s0 \s-1SETTINGS\s0"
509 .IX Subsection "NODE SPECIFIC SETTINGS"
510 The following settings are node-specific, that is, every node can have
511 different settings, even within the same gvpe instance. Settings that are
512 set before the first node section set the defaults, settings that are
513 set within a node section only apply to the given node.
514 .IP "allow-direct = nodename" 4
515 .IX Item "allow-direct = nodename"
516 Allow direct connections to this node. See \f(CW\*(C`deny\-direct\*(C'\fR for more info.
517 .IP "compress = yes|true|on | no|false|off" 4
518 .IX Item "compress = yes|true|on | no|false|off"
519 Wether to compress data packets sent to this node (default: \f(CW\*(C`yes\*(C'\fR).
520 Compression is really cheap even on slow computers and has no size
521 overhead at all, so enabling this is often a good idea.
522 .IP "connect = ondemand | never | always | disabled" 4
523 .IX Item "connect = ondemand | never | always | disabled"
524 Sets the connect mode (default: \f(CW\*(C`always\*(C'\fR). It can be \f(CW\*(C`always\*(C'\fR (always
525 try to establish and keep a connection to the given node), \f(CW\*(C`never\*(C'\fR
526 (never initiate a connection to the given host, but accept connections),
527 \&\f(CW\*(C`ondemand\*(C'\fR (try to establish a connection when there are outstanding
528 packets in the queue and take it down after the keepalive interval) or
529 \&\f(CW\*(C`disabled\*(C'\fR (node is bad, don't talk to it).
530 .Sp
531 Routers will automatically be forced to \f(CW\*(C`always\*(C'\fR unless they are
532 \&\f(CW\*(C`disabled\*(C'\fR, to ensure all nodes can talk to each other.
533 .IP "deny-direct = nodename | *" 4
534 .IX Item "deny-direct = nodename | *"
535 Deny direct connections to the specified node (or all nodes when \f(CW\*(C`*\*(C'\fR
536 is given). Only one node can be specified, but you can use multiple
537 \&\f(CW\*(C`allow\-direct\*(C'\fR and \f(CW\*(C`deny\-direct\*(C'\fR statements. This only makes sense in
538 networks with routers, as routers are required for indirect connections.
539 .Sp
540 Sometimes, a node cannot reach some other nodes for reasons of network
541 connectivity. For example, a node behind a firewall that only allows
542 connections to/from a single other node in the network. In this case one
543 should specify \f(CW\*(C`deny\-direct = *\*(C'\fR and \f(CW\*(C`allow\-direct = othernodename\*(C'\fR (the other
544 node \fImust\fR be a router for this to work).
545 .Sp
546 The algorithm to check whether a connection may be direct is as follows:
547 .Sp
548 1. Other node mentioned in an \f(CW\*(C`allow\-direct\*(C'\fR? If yes, allow the connection.
549 .Sp
550 2. Other node mentioned in a \f(CW\*(C`deny\-direct\*(C'\fR? If yes, deny direct connections.
551 .Sp
552 3. Allow the connection.
553 .Sp
554 That is, \f(CW\*(C`allow\-direct\*(C'\fR takes precedence over \f(CW\*(C`deny\-direct\*(C'\fR.
555 .Sp
556 The check is done in both directions, i.e. both nodes must allow a direct
557 connection before one is attempted, so you only need to specify connect
558 limitations on one node.
559 .IP "dns-domain = domain-suffix" 4
560 .IX Item "dns-domain = domain-suffix"
561 The \s-1DNS\s0 domain suffix that points to the \s-1DNS\s0 tunnel server for this node.
562 .Sp
563 The domain must point to a \s-1NS\s0 record that points to the \fIdns-hostname\fR,
564 i.e.
565 .Sp
566 .Vb 2
567 \& dns\-domainname = tunnel.example.net
568 \& dns\-hostname = tunnel\-server.example.net
569 .Ve
570 .Sp
571 Corresponds to the following \s-1DNS\s0 entries in the \f(CW\*(C`example.net\*(C'\fR domain:
572 .Sp
573 .Vb 2
574 \& tunnel.example.net. NS tunnel\-server.example.net.
575 \& tunnel\-server.example.net. A 13.13.13.13
576 .Ve
577 .IP "dns-hostname = hostname/ip" 4
578 .IX Item "dns-hostname = hostname/ip"
579 The address to bind the \s-1DNS\s0 tunnel socket to, similar to the \f(CW\*(C`hostname\*(C'\fR,
580 but for the \s-1DNS\s0 tunnel protocol only. Default: \f(CW0.0.0.0\fR, but that might
581 change.
582 .IP "dns-port = port-number" 4
583 .IX Item "dns-port = port-number"
584 The port to bind the \s-1DNS\s0 tunnel socket to. Must be \f(CW53\fR on \s-1DNS\s0 tunnel servers.
585 .IP "enable-dns = yes|true|on | no|false|off" 4
586 .IX Item "enable-dns = yes|true|on | no|false|off"
587 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1DNS\s0 transport
588 protocol. Avoid this protocol if you can.
589 .Sp
590 Enable the \s-1DNS\s0 tunneling protocol on this node, either as server or as
591 client. Support for this transport protocol is only available when gvpe
592 was compiled using the \f(CW\*(C`\-\-enable\-dns\*(C'\fR option.
593 .IP "enable-icmp = yes|true|on | no|false|off" 4
594 .IX Item "enable-icmp = yes|true|on | no|false|off"
595 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1ICMP\s0 transport protocol.
596 .Sp
597 Enable the \s-1ICMP\s0 transport using \s-1ICMP\s0 packets of type \f(CW\*(C`icmp\-type\*(C'\fR on this
598 node.
599 .IP "enable-rawip = yes|true|on | no|false|off" 4
600 .IX Item "enable-rawip = yes|true|on | no|false|off"
601 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1RAW\s0 \s-1IP\s0 transport protocol.
602 .Sp
603 Enable the \s-1RAW\s0 IPv4 transport using the \f(CW\*(C`ip\-proto\*(C'\fR protocol
604 (default: \f(CW\*(C`no\*(C'\fR).
605 .IP "enable-tcp = yes|true|on | no|false|off" 4
606 .IX Item "enable-tcp = yes|true|on | no|false|off"
607 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1TCP\s0 transport protocol.
608 .Sp
609 Enable the TCPv4 transport using the \f(CW\*(C`tcp\-port\*(C'\fR port
610 (default: \f(CW\*(C`no\*(C'\fR). Support for this transport protocol is only available
611 when gvpe was compiled using the \f(CW\*(C`\-\-enable\-tcp\*(C'\fR option.
612 .IP "enable-udp = yes|true|on | no|false|off" 4
613 .IX Item "enable-udp = yes|true|on | no|false|off"
614 See \fIgvpe.protocol\fR\|(7) for a description of the \s-1UDP\s0 transport protocol.
615 .Sp
616 Enable the UDPv4 transport using the \f(CW\*(C`udp\-port\*(C'\fR port (default: \f(CW\*(C`no\*(C'\fR,
617 unless no other protocol is enabled for a node, in which case this
618 protocol is enabled automatically).
619 .Sp
620 \&\s-1NOTE:\s0 Please specify \f(CW\*(C`enable\-udp = yes\*(C'\fR if you want to use it even though
621 it might get switched on automatically, as some future version might
622 default to another default protocol.
623 .IP "hostname = hostname | ip [can not be defaulted]" 4
624 .IX Item "hostname = hostname | ip [can not be defaulted]"
625 Forces the address of this node to be set to the given \s-1DNS\s0 hostname or \s-1IP\s0
626 address. It will be resolved before each connect request, so dyndns should
627 work fine. If this setting is not specified and a router is available,
628 then the router will be queried for the address of this node. Otherwise,
629 the connection attempt will fail.
630 .Sp
631 Note that \s-1DNS\s0 resolving is done synchronously, pausing the daemon. If that
632 is an issue you need to specify \s-1IP\s0 addresses.
633 .IP "icmp-type = integer" 4
634 .IX Item "icmp-type = integer"
635 Sets the type value to be used for outgoing (and incoming) packets sent
636 via the \s-1ICMP\s0 transport.
637 .Sp
638 The default is \f(CW0\fR (which is \f(CW\*(C`echo\-reply\*(C'\fR, also known as
639 \&\*(L"ping-reply\*(R"). Other useful values include \f(CW8\fR (\f(CW\*(C`echo\-request\*(C'\fR, a.k.a.
640 \&\*(L"ping\*(R") and \f(CW11\fR (\f(CW\*(C`time\-exceeded\*(C'\fR), but any 8\-bit value can be used.
641 .IP "if-up-data = value" 4
642 .IX Item "if-up-data = value"
643 The value specified using this directive will be passed to the \f(CW\*(C`if\-up\*(C'\fR
644 script in the environment variable \f(CW\*(C`IFUPDATA\*(C'\fR.
645 .IP "inherit-tos = yes|true|on | no|false|off" 4
646 .IX Item "inherit-tos = yes|true|on | no|false|off"
647 Wether to inherit the \s-1TOS\s0 settings of packets sent to the tunnel when
648 sending packets to this node (default: \f(CW\*(C`yes\*(C'\fR). If set to \f(CW\*(C`yes\*(C'\fR then
649 outgoing tunnel packets will have the same \s-1TOS\s0 setting as the packets sent
650 to the tunnel device, which is usually what you want.
651 .IP "max-retry = positive-number" 4
652 .IX Item "max-retry = positive-number"
653 The maximum interval in seconds (default: \f(CW3600\fR, one hour) between
654 retries to establish a connection to this node. When a connection cannot
655 be established, gvpe uses exponential back-off capped at this value. It's
656 sometimes useful to set this to a much lower value (e.g. \f(CW120\fR) on
657 connections to routers that usually are stable but sometimes are down, to
658 assure quick reconnections even after longer downtimes.
659 .IP "max-ttl = seconds" 4
660 .IX Item "max-ttl = seconds"
661 Expire packets that couldn't be sent after this many seconds
662 (default: \f(CW60\fR). Gvpe will normally queue packets for a node without an
663 active connection, in the hope of establishing a connection soon. This
664 value specifies the maximum lifetime a packet will stay in the queue, if a
665 packet gets older, it will be thrown away.
666 .IP "max-queue = positive\-number>=1" 4
667 .IX Item "max-queue = positive-number>=1"
668 The maximum number of packets that will be queued (default: \f(CW512\fR)
669 for this node. If more packets are sent then earlier packets will be
670 expired. See \f(CW\*(C`max\-ttl\*(C'\fR, above.
671 .IP "router-priority = 0 | 1 | positive\-number>=2" 4
672 .IX Item "router-priority = 0 | 1 | positive-number>=2"
673 Sets the router priority of the given node (default: \f(CW0\fR, disabled).
674 .Sp
675 If some node tries to connect to another node but it doesn't have a
676 hostname, it asks a router node for it's \s-1IP\s0 address. The router node
677 chosen is the one with the highest priority larger than \f(CW1\fR that is
678 currently reachable. This is called a \fImediated\fR connection, as the
679 connection itself will still be direct, but it uses another node to
680 mediate between the two nodes.
681 .Sp
682 The value \f(CW0\fR disables routing, that means if the node receives a packet
683 not for itself it will not forward it but instead drop it.
684 .Sp
685 The special value \f(CW1\fR allows other hosts to route through the router
686 host, but they will never route through it by default (i.e. the config
687 file of another node needs to specify a router priority higher than one
688 to choose such a node for routing).
689 .Sp
690 The idea behind this is that some hosts can, if required, bump the
691 \&\f(CW\*(C`router\-priority\*(C'\fR setting to higher than \f(CW1\fR in their local config to
692 route through specific hosts. If \f(CW\*(C`router\-priority\*(C'\fR is \f(CW0\fR, then routing
693 will be refused, so \f(CW1\fR serves as a \*(L"enable, but do not use by default\*(R"
694 switch.
695 .Sp
696 Nodes with \f(CW\*(C`router\-priority\*(C'\fR set to \f(CW2\fR or higher will always be forced
697 to \f(CW\*(C`connect\*(C'\fR = \f(CW\*(C`always\*(C'\fR (unless they are \f(CW\*(C`disabled\*(C'\fR).
698 .IP "tcp-port = port-number" 4
699 .IX Item "tcp-port = port-number"
700 Similar to \f(CW\*(C`udp\-port\*(C'\fR (default: \f(CW655\fR), but sets the \s-1TCP\s0 port number.
701 .IP "udp-port = port-number" 4
702 .IX Item "udp-port = port-number"
703 Sets the port number used by the \s-1UDP\s0 protocol (default: \f(CW655\fR, not
704 officially assigned by \s-1IANA\s0!).
705 .SH "CONFIG DIRECTORY LAYOUT"
706 .IX Header "CONFIG DIRECTORY LAYOUT"
707 The default (or recommended) directory layout for the config directory is:
708 .IP "gvpe.conf" 4
709 .IX Item "gvpe.conf"
710 The config file.
711 .IP "if-up" 4
712 .IX Item "if-up"
713 The if-up script
714 .IP "node-up, node-down" 4
715 .IX Item "node-up, node-down"
716 If used the node up or node-down scripts.
717 .IP "hostkey" 4
718 .IX Item "hostkey"
719 The private key (taken from \f(CW\*(C`hostkeys/nodename\*(C'\fR) of the current host.
720 .IP "pubkey/nodename" 4
721 .IX Item "pubkey/nodename"
722 The public keys of the other nodes, one file per node.
723 .SH "SEE ALSO"
724 .IX Header "SEE ALSO"
725 \&\fIgvpe\fR\|(5), \fIgvpe\fR\|(8), \fIgvpectrl\fR\|(8).
726 .SH "AUTHOR"
727 .IX Header "AUTHOR"
728 Marc Lehmann <gvpe@schmorp.de>