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14 <h2>Hops, Network Isolation and other matters...</h2>
19 <address><a href="mailto:djk@tobit.co.uk">Dirk Koopman G1TLH</a></address>
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28 Starting with version 1.13 there is simple hop control available on a per
29 node basis. Also it is possible to isolate a network completely so that you
30 get all the benefits of being on that network, but can't pass on information
32 to any other networks you may be connected to (or vice versa).
34 <h4>Basic Hop Control</h4>
36 The number of hops that are set for all PC protocol messages (that require them)
37 are specified in <tt>/spider/perl/DXProtVars.pm</tt>.
39 <p>In versions prior to 1.13 you would move this file to
40 <tt>/spider/local/</tt> and modify the perl variables:
41 <tt>$def_hopcount</tt> and <tt>%hopcount</tt> to some reasonable
44 <p>From version 1.13 onwards a new mechanism has been introduced
45 which uses a file called <tt>/spider/data/hop_table.pl</tt>. The
46 prefered way of doing basic hop control is now to create this file
47 and modify it as you wish. Eventually this file will contain all
48 the hop control and related information. An example of the
49 <tt>hop_table.pl</tt> file can be found in the
50 <tt>/spider/examples</tt> directory.
52 <p>You can change this file at any time, including when the
53 cluster is running. If you do this then the changes only take
54 effect after you have run the <tt>load/hops</tt> command on a
55 client console with full sysop privileges.
57 <h4>Per Node Hop Control</h4>
59 From version 1.13 it is possible to control the number of hops to each
60 node. This is done by adding information to the <tt>%nodehops</tt> perl
61 variable in the <tt>hop_table.pl</tt> file (as described above). This
62 variable is a perl "hash of hashes", which means that you create an
63 entry for every callsign you wish to control and then one line for
64 every PC protocol message that you wish to alter.
66 <p>You can also have a entry called <tt>default</tt> for every callsign
67 so you can set the hops as a whole for all PC messages to just that
68 callsign. This is overridden by any specific hop counts you may have.
70 <h4>Example <tt>hop_table.pl</tt> File</h4>
76 # hop table construction
81 # default hopcount to use
84 # some variable hop counts based on message type
95 # the per node hop control thingy
119 <p>The figures chosen are not necessarily what I use. What I would say is that
120 until you are certain that you know what you are doing (and that the software
121 is working at least as well as advertised) you should keep the default hop
122 counts down to the sort of levels shown above.
124 <h4><a name="isolate"></a>Isolated Networks</h4>
126 It is possible to isolate networks from each other on a "gateway" node using
127 the <tt>set/isolate <node call></tt> command.
129 <p>The effect of this is to partition an isolated network
130 completely from another nodes connected to your node. Your node
131 will appear on and otherwise behave normally on every network to
132 which you are connected, but data from isolated network will not
133 cross onto any other network or vice versa.
135 <P>However all the spot, announce and WWV traffic and personal
136 messages will still be handled locally (because you are a real
137 node on all connected networks), that is locally connected users
138 will appear on all networks and will be able to access and receive
139 information from all networks transparently.
141 <p>All routed messages will be sent as normal, so if a user on one
142 network knows that you are a gateway for another network, he can still
143 still send a talk/announce etc message via your node and it will
146 <p>The only limitation currently is that non-private messages
147 cannot be passed down isolated links regardless of whether they
148 are generated locally. This will change when the bulletin routing
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156 Copyright © 1998 by Dirk Koopman G1TLH. All Rights Reserved<br>
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