[aprssig] aprsd Configurations

AE5PL Lists HamLists at ametx.com
Sat Nov 13 09:31:28 EST 2004

It has come to my attention that packets are being dropped from certain
aprsd servers due to configuration issues and a bug in the aprsd code.
There are certain servers that are configured with HUB-RO and SERVER-SR.
The purpose of HUB and SERVER is actually reversed from this setting and
should be HUB-SR and SERVER-RO  (SR means send/receive and RO means
receive-only).  The idea is, to help prevent loops, that only one
bidirectional connection is made outbound from the server.

So, making this change will help, but there is a code change that is
necessary for multiple connections from aprsd to be properly accepted by
javAPRSSrvr's.  javAPRSSrvr assumes that a packet heard from a
server/client that is connected via a verified login but via a different
connection is a looped packet and that packet is dropped
(http://www.aprs-is.net/q.htm).  aprsd uses a verified login for its
read-only connections.  This causes those connections to potentially
make packets appear looped since the packets will come from a different
connection.  aprsd should be modified to use a passcode of -1 for its
outbound receive-only connections.

Lot of info, but the net of it is:

Connections to the core servers (or any APRS-IS server) should be
exclusively HUB-SR.

SERVER-SR should not be used except in the rare circumstance where the
connection is to a client with no outbound capability.

HUB-RO should not be used.

SERVER-RO should be avoided and only used if the following modification
is made.

aprsd code should be modified and recompiled so that SERVER-RO and
HUB-RO connections use -1 for a passcode.

aprsd sysops, please review your configurations.


Pete Loveall AE5PL
mailto:pete at ae5pl.net 

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