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14 <h2>Connecting to other Clusters</h2>
19 <address><a href="mailto:djk@tobit.co.uk">Dirk Koopman G1TLH</a></address>
21 <!-- Created: Sun Dec 13 20:25:14 GMT 1998 -->
23 Last modified: Sun Sep 2 21:12:19 BST 2001
25 <p>At the moment, anybody can connect inwards at any time from outside, either by ax25 or by
26 telnet (assuming you have followed the instructions in <a href="install.html">installation</a>
27 instructions. However, in order to connect outwards, you will need to create <em>connect</em> scripts.
29 <p><em>Connect</em> scripts live in the <tt>/spider/connect</tt> directory and are simple ascii scripts
30 that are written using a normal editor. There are a couple of examples in the issue directory.
32 <p>The first example is a simple telnet (TCP/IP) connect to port 7000 of WR3D (this will actually
33 work if you have or make an arrangement to connect to WR3D)[oh, and substitute x1xxx for your real
36 <p>The colouration will be explained later on in this page, you don't have to try to emulate the colours!</p>
39 <span class=cmd>timeout 15</span>
41 <span class=connect>connect telnet wr3d.dxcluster.net 7000</span>
42 <span class=expect>'login'</span> <span class=send>'x1xxx'</span>
43 <span class=cmd>client wr3d telnet</span>
46 <p>If you put the above script in a file called: <tt>/spider/connect/wr3d</tt> then you can leave out
47 line: <span class=cmd>client wr3d telnet</span>.
48 <p>For a connect that requires a login and execution of the programs
49 from a normal shell, do:-</p>
52 <span class=cmd>timeout 15</span>
53 <span class=connect>connect telnet dirkl.tobit.co.uk</span>
54 <span class=expect>'login'</span> <span class=send>'gb7djk'</span>
55 <span class=expect>'word'</span> <span class=send>'gb7djk'</span>
56 <span class=expect>'\$'</span> <span class=send>'cd /spider/perl'</span>
57 # set the line to prevent echoing, leaving this out will
58 # confuse whole networks for hours!
59 <span class=expect>'\$'</span> <span class=send>'stty -echo raw'</span>
60 # tell GB7DJK that you are GB7DJK-1
61 <span class=expect>'\$'</span> <span class=send>'/spider/src/client gb7djk-1 telnet'</span>
62 # tell GB7DJK-1 that it is connected to GB7DJK
63 # you can leave this out if you call this script 'gb7djk'
64 <span class=cmd>client gb7djk telnet</span>
67 <p>a ax25 example (connecting from GB7DJK, to GB7DXM via my local BPQ node and one X1J intermediate node):-
70 <span class=cmd>timeout 60</span>
71 <span class=cmd>abort (Busy|Sorry|Fail)</span>
72 # don't forget to chmod 4775 netrom_call!
73 <span class=connect>connect ax25 /usr/sbin/netrom_call bbs gb7djk-0 g1tlh-0</span>
74 <span class=expect>'Connected'</span> <span class=send>''</span>
75 <span class=expect>'Connected'</span> <span class=send>'c np7'</span>
76 <span class=expect>'*** Connect'</span> <span class=send>'c gb7dxm'</span>
77 <span class=expect>'Connect'</span> <span class=send>''</span>
80 <p>The <tt>-0</tt> ssid is important if you want it to work reliably. Obviously if you are
81 using a different ssid then you would use that. You can use the Netrom alias instead if it
82 it is in the machines node table</p>
84 <p>A AGW Engine example would be very similar and look like this:-</p>
87 <span class=cmd>timeout 60</span>
88 <span class=cmd>abort (Busy|Sorry|Fail)</span>
89 <span class=connect>connect agw 2 g1tlh</span>
90 <span class=expect>'*** Connected'</span> <span class=send>''</span>
91 <span class=expect>'*** Connect'</span> <span class=send>'c np7'</span>
92 <span class=expect>'Connected'</span> <span class=send>'c gb7dxm'</span>
93 <span class=expect>'Connect'</span> <span class=send>''</span>
96 <p>A connection is started manually by typing in <tt>connect <scriptname></tt> on a sysop enabled
97 <tt>client.pl</tt> session. For example:-</p>
100 G1TLH de GB7DJK 13-Dec-1998 2041Z > connect gb7djk-1
101 connection to GB7DJK-1 started
102 G1TLH de GB7DJK 13-Dec-1998 2043Z >
105 <p>Consider the following specific example, it is located in the file <tt>/spider/connect/gb7djk-1</tt> :-</p>
108 <span class=cmd>timeout 15</span>
109 <span class=connect>connect telnet dirkl.tobit.co.uk</span>
110 <span class=expect>'login'</span> <span class=send>'gb7djk'</span>
111 <span class=expect>'ssword'</span> <span class=send>'gb7djk'</span>
114 <p>You can watch the progress of the connection (if you have <tt>connect</tt>
115 debugging enabled [<tt>set/debug connect</tt>]) on the
116 <tt>cluster.pl</tt> screen and you should see something like this:-</p>
119 <- D G1TLH connect gb7djk-1
120 -> D G1TLH connection to GB7DJK-1 started
121 -> D G1TLH G1TLH de GB7DJK 13-Dec-1998 2046Z >
122 <span class=cmd>timeout set to 15</span>
123 <span class=connect>CONNECT sort: telnet command: dirkl.tobit.co.uk</span>
124 CHAT "login" -> "gb7djk"
126 Red Hat Linux release 5.1 (Manhattan)
127 Kernel 2.0.35 on an i586
129 <span class=expect>received "login: "</span>
130 <span class=send>sent "gb7djk"</span>
131 CHAT "word" -> "gb7djk"
135 <span class=expect>received "Password: "</span>
136 <span class=send>sent "gb7djk"</span>
137 Connected to GB7DJK-1, starting normal protocol
138 <- O GB7DJK-1 telnet
140 GB7DJK-1 channel func state 0 -> init
142 <- D GB7DJK-1 Last login: Sun Dec 13 17:59:56 from dirk1
143 <- D GB7DJK-1 PC38^GB7DJK-1^~
144 <- D GB7DJK-1 PC18^ 1 nodes, 0 local / 1 total users Max users 0 Uptime 0 00:00^5447^~
148 <p>I have coloured the commands in an attempt to make it clear as
149 to what goes on, where and why. Lines that are <span
150 class=cmd>coloured thus</span> are miscellaneous setup
151 commands. Lines that are <span class=connect>this colour</span>
152 are lines that make the initial <span
153 class=connect>connection</span> to the first hop. The things that
154 are <span class=expect>this colour</span> are the strings I am
155 looking for (what I am <span class=expect>"expecting"</span>) and
156 the things that are <span class=send>this colour</span> are the
157 commands I am going to <span class=send>send</span> when I see the
158 "expect" strings in the input.</p>
160 <p>The script starts by setting the timeout to 15 seconds, then starts
161 the connection. It is <b>important</b> to note that, in the case of
162 an ax25 connection (usually) this will be the callsign of the <i>first hop</i> along the
163 route that you are going to take to the destination, so this will be typically the callsign
164 of your local node.</p>
166 <p>You will notice that the script waits until it sees the left hand string
167 of the pair and <b>only then</b> does it send the,
169 hand side. This is called a <i>State Machine</i>.</p>
171 <p>A <i>state machine</i> "walks" through a conversation (in this case) looking
172 for "states" (in this case particular strings) and then performs some
173 "action" (usually some kind of connect command for the type of system
174 you are trying to navigate). When one "state" "fires" (detects the string
175 are looking for), it sends the command associated with that state and then
176 moves onto the next "state", in our case: the next line.</p>
178 <p><b>PLEASE NOTE</b>: the colouration in the above example is for illustrative purposes
179 only, the debug output is all one colour.</p>
181 <p>The connect scripts consist of lines which start with the
182 following keywords or symbols:-</p>
186 <li><b>#</b> All lines starting with a <b>#</b> are
187 ignored, as are wholly blank lines.
190 <li><b>timeout</b> followed by a number is the number of
191 seconds to wait for a command to complete. If there is no
192 <b>timeout</b> specified in the script then the default is 60
196 <li><b>abort</b> is a regular expression containing one or
197 more strings to look for to abort a connection. This is a perl
198 regular expression and is executed ignoring case.
201 <li><b>connect</b> followed by <b>ax25</b>, <b>telnet</b> or <b>agw</b>
202 and some type dependent information.
205 <b>telnet</b> connection, there can be up to two parameters,
206 the first is the ip address or hostname of the computer you
207 wish to connect to and the second is the port number you want
208 to use (this can be left out if it is a normal telnet
211 <p>In the case of an <b>ax25</b> session then this would
212 normally be a call to <tt>/usr/sbin/ax25_call</tt> or
213 <tt>/usr/sbin/netrom_call</tt> as in the example above. It is your
214 responsibility to get your node and other ax25 parameters to
215 work before going down this route!
217 <p>For <b>agw</b> connections you will need a port number (starting
218 from 1) and the callsign of the first "hop" along the way.
221 <li><b>'</b> is the delimiting character for a word or
222 phrase of an expect/send line in a <tt>chat</tt> type
223 script. The words/phrases normally come in pairs, either can
224 be empty. Each line reads input from the connection until it
225 sees the string (or perl regular expression) contained in the
226 left hand string. If the left hand string is empty then it
227 doesn't read or wait for anything. The comparison is done
230 <p>When the left hand string has found what it is looking (if
231 it is) then the right hand string is sent to the connection.
233 <p>This process is repeated for every line of <tt>chat</tt> script.
236 <li><b>client</b> starts the connection, put the arguments
237 you would want here if you were starting the client program
238 manually. You only need this if the script has a different
239 name to the callsign you are trying to connect to (i.e. you
240 have a script called <tt>other</tt> which actually connects to
241 <tt>GB7DJK-1</tt> [instead of a script called
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249 <span class=copy>Copyright © 1998 by Dirk Koopman G1TLH. All Rights Reserved</span><br>
250 <span class=id>$Id$</span>