[ViewVC] Diff of: cvs/gvpe/doc/gvpe.conf.5.pod

Comparing gvpe/doc/gvpe.conf.5.pod (file contents):
Revision 1.14 by pcg, Tue Jun 21 08:46:53 2005 UTC vs.
Revision 1.20 by pcg, Sun Aug 10 22:18:58 2008 UTC

 listen on), followed by node-specific sections that begin with a C<node =
 nickname> line.
 Every node that is part of the network must have a section that starts
 with C<node = nickname>. The number and order of the nodes is important
-and must be the same on all hosts. It is not uncommon for node sections to
+and must be the same on all nodes. It is not uncommon for node sections to
 be completely empty - if the default values are right.
 Node-specific settings can be used at any time. If used before the first
 node section they will set the default values for all following nodes.
 get request timeouts. The default of C<8> means that the DNS transport
 will resend the request when no reply has been received for longer than
 eight times the minimum (= expected) latency, assuming the request or
 reply has been lost.
-For congested links a higher value might be necessary (e.g. C<30>). If the
+For congested links a higher value might be necessary (e.g. C<30>). If
-link is very stable lower values (e.g. C<2>) might work nicely. Values
+the link is very stable lower values (e.g. C<2>) might work
-near or below C<1> makes no sense whatsoever.
+nicely. Values near or below C<1> makes no sense whatsoever.
-The default should be working ok for most links.
+The default should be working ok for most links but will result in low
+throughput if packet loss is high.
 =item if-up = relative-or-absolute-path
 Sets the path of a script that should be called immediately after the
 network interface is initialized (but not neccessarily up). The following
 select the correct syntax to use for network-related commands.
 =item MTU=1436
 The MTU to set the interface to. You can use lower values (if done
-consistently on all hosts), but this is usually ineffective.
+consistently on all nodes), but this is usually either inefficient or
+simply ineffective.
 =item NODES=5
 The number of nodes in this GVPE network.
 device.
 =item ip-proto = numerical-ip-protocol
 Sets the protocol number to be used for the rawip protocol. This is a
-global option because all hosts must use the same protocol, and since
+global option because all nodes must use the same protocol, and since
 there are no port numbers, you cannot easily run more than one gvpe
 instance using the same protocol, nor can you share the protocol with
 other programs.
 The default is 47 (GRE), which has a good chance of tunneling through
 Please note that gvpe will still try to resolve all hostnames in the
 configuration file, so if you are behind a proxy without access to a dns
 server better use numerical IP addresses.
 To make best use of this option disable all protocols except tcp in your
-config file and make sure your routers (or all other hosts) are listening
+config file and make sure your routers (or all other nodes) are listening
 on a port that the proxy allows (443, https, is a common choice).
 If you have a router, connecting to it will suffice. Otherwise tcp must be
-enabled on all hosts.
+enabled on all nodes.
 Example:
    http-proxy-host = proxy.example.com
    http-proxy-port = 3128	# 8080 is another common choice
 maximum overhead (e.g. udp header size, encryption blocksize...) and pass
 this information to the C<if-up> script.
 Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
-This value must be the minimum of the mtu values of all hosts.
+This value must be the minimum of the mtu values of all nodes.
 =item node = nickname
 Not really a config setting but introduces a node section. The nickname is
 used to select the right configuration section and must be passed as an
 argument to the gvpe daemon.
 =item node-up = relative-or-absolute-path
-Sets a command (default: no script) that should be called whenever a
+Sets a command (default: none) that should be called whenever a connection
-connection is established (even on rekeying operations). In addition to
+is established (even on rekeying operations). Note that node-up/down
+scripts will be run asynchronously, but execution is serialised, so there
+will only ever be one such script running.
-all the variables passed to C<if-up> scripts, the following environment
+In addition to all the variables passed to C<if-up> scripts, the following
-variables will be set:
+environment variables will be set:
 =over 4
 =item DESTNODE=branch2
 The node id of the remote node.
 =item DESTIP=188.13.66.8
-The numerical IP address of the remote host (gvpe accepts connections from
+The numerical IP address of the remote node (gvpe accepts connections from
-everywhere, as long as the other host can authenticate itself).
+everywhere, as long as the other node can authenticate itself).
 =item DESTPORT=655 # deprecated
 The UDP port used by the other side.
 be doubled. A single C<%s> is replaced by the hostname, so you could
 use paths like C<hostkeys/%s> to fetch the files at the location where
 C<gvpectrl> puts them.
 Since only the private key file of the current node is used and the
-private key file should be kept secret per-host to avoid spoofings, it is
+private key file should be kept secret per-node to avoid spoofings, it is
 not recommended to use this feature.
 =item rekey = seconds
 Sets the rekeying interval in seconds (default: C<3600>). Connections are
 =head2 NODE SPECIFIC SETTINGS
 The following settings are node-specific, that is, every node can have
 different settings, even within the same gvpe instance. Settings that are
-executed before the first node section set the defaults, settings that are
+set before the first node section set the defaults, settings that are
-executed within a node section only apply to the given node.
+set within a node section only apply to the given node.
 =over 4
+=item allow-direct = nodename
+Allow direct connections to this node. See C<deny-direct> for more info.
 =item compress = yes|true|on | no|false|off
-Wether to compress data packets sent to this host (default: C<yes>).
+Wether to compress data packets sent to this node (default: C<yes>).
 Compression is really cheap even on slow computers and has no size
 overhead at all, so enabling this is a good idea.
 =item connect = ondemand | never | always | disabled
 Sets the connect mode (default: C<always>). It can be C<always> (always
-try to establish and keep a connection to the given host), C<never>
+try to establish and keep a connection to the given node), C<never>
 (never initiate a connection to the given host, but accept connections),
-C<ondemand> (try to establish a connection on the first packet sent, and
+C<ondemand> (try to establish a connection when there are outstanding
-take it down after the keepalive interval) or C<disabled> (node is bad,
+packets in the queue and take it down after the keepalive interval) or
-don't talk to it).
+C<disabled> (node is bad, don't talk to it).
+Routers will automatically be forced to C<always> unless they are
+C<disabled>, to ensure all nodes can talk to each other.
+=item deny-direct = nodename | *
+Deny direct connections to the specified node (or all nodes when C<*>
+is given). Only one node can be specified, but you can use multiple
+C<allow-direct> and C<deny-direct> statements. This only makes sense in
+networks with routers, as routers are required for indirect connections.
+Sometimes, a node cannot reach some other nodes for reasons of network
+connectivity. For example, a node behind a firewall that only allows
+conenctions to/from a single other node in the network. In this case one
+should specify C<deny-direct = *> and C<allow-direct = othernodename> (the other
+node I<must> be a router for this to work).
+The algorithm to check wether a connection may be direct is as follows:
+1. Other node mentioned in a C<allow-direct>? If yes, allow the connection.
+2. Other node mentioned in a C<deny-direct>? If yes, deny direct connections.
+3. Allow the connection.
+That is, C<allow-direct> takes precedence over C<deny-direct>.
+The check is done in both directions, i.e. both nodes must allow a direct
+connection before one is attempted, so you only need to specify connect
+limitations on one node.
 =item dns-domain = domain-suffix
 The DNS domain suffix that points to the DNS tunnel server for this node.
 protocol is enabled automatically).
 NOTE: Please specify C<enable-udp = yes> if you want t use it even though
 it might get switched on automatically, as some future version might
 default to another default protocol.
+=item hostname = hostname | ip    [can not be defaulted]
+Forces the address of this node to be set to the given dns hostname or ip
+address. It will be resolved before each connect request, so dyndns should
+work fine. If this setting is not specified and a router is available,
+then the router will be queried for the address of this node. Otherwise,
+the connection attempt will fail.
 =item icmp-type = integer
 Sets the type value to be used for outgoing (and incoming) packets sent
 via the ICMP transport.
 be established, gvpe uses exponential backoff capped at this value. It's
 sometimes useful to set this to a much lower value (e.g. C<120>) on
 connections to routers that usually are stable but sometimes are down, to
 assure quick reconnections even after longer downtimes.
+=item max-ttl = seconds
+Expire packets that couldn't be sent after this many seconds
+(default: C<60>). Gvpe will normally queue packets for a node without an
+active connection, in the hope of establishing a connection soon. This
+value specifies the maximum lifetime a packet will stay in the queue, if a
+packet gets older, it will be thrown away.
+=item max-queue = positive-number>=1
+The maximum number of packets that will be queued (default: C<512>)
+for this node. If more packets are sent then earlier packets will be
+expired. See C<max-ttl>, above.
 =item router-priority = 0 | 1 | positive-number>=2
-Sets the router priority of the given host (default: C<0>, disabled). If
+Sets the router priority of the given node (default: C<0>, disabled).
-some host tries to connect to another host without a hostname, it asks
-the router host for it's IP address. The router host is the one with the
-highest priority larger than C<1> that is currently reachable.
-Make sure all hosts always connect (C<connect = always>) to the router
+If some node tries to connect to another node but it doesn't have a
-hosts, otherwise connecting to them might be impossible.
+hostname, it asks a router node for it's IP address. The router node
+chosen is the one with the highest priority larger than C<1> that is
+currently reachable. This is called a I<mediated> connection, as the
+connection itself will still be direct, but it uses another node to
+mediate between the two nodes.
+The value C<0> disables routing, that means if the node receives a packet
+not for itself it will not forward it but instead drop it.
 The special value C<1> allows other hosts to route through the router
-host, but they will never route through it by default. The value C<0>
+host, but they will never route through it by default (i.e. the config
-disables routing. The idea behind this is that some hosts can, if
+file of another node needs to specify a router priority higher than one
+to choose such a node for routing).
+The idea behind this is that some hosts can, if required, bump the
-required, bump the C<router-priority> setting to higher than C<1> in their
+C<router-priority> setting to higher than C<1> in their local config to
-local config to route through specific hosts. If C<router-priority> is
+route through specific hosts. If C<router-priority> is C<0>, then routing
-C<0>, then routing will be refused, so C<1> serves as a "enable, but do
+will be refused, so C<1> serves as a "enable, but do not use by default"
-not use by default" switch.
+switch.
+Nodes with C<router-priority> set to C<2> or higher will always be forced
+to C<connect> = C<always> (unless they are C<disabled>).
 =item tcp-port = port-number
 Similar to C<udp-port> (default: C<655>), but sets the TCP port number.

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Comparing gvpe/doc/gvpe.conf.5.pod (file contents): Revision 1.14 by pcg, Tue Jun 21 08:46:53 2005 UTC vs. Revision 1.20 by pcg, Sun Aug 10 22:18:58 2008 UTC

Diff Legend

Comparing gvpe/doc/gvpe.conf.5.pod (file contents):
Revision 1.14 by pcg, Tue Jun 21 08:46:53 2005 UTC vs.
Revision 1.20 by pcg, Sun Aug 10 22:18:58 2008 UTC