Thinklogical Router - Configuring the ASCII Interface - Manual (Page 9)

Using Multicast to send Router Status instead of
Network Broadcast
Version 4.5 (and later) of the API has a command line option to use a network multicast address
instead of a broadcast address to deliver router status messages. The default mode of the API is
to broadcast over the network its' status. The use of a multicast address allows these messages
to be routed to other network segments. If all this is foreign to you, don't worry, just forget about
it and use the default settings.
The command line option to enable multicast is '--mcast'. Without any additional options, it will
enable multicast using the default IP address of 239.255.13.9. When multicasting is enabled, the
API will create a log entry showing the IP address it is using.
May 20 16:18:06 vxrouter vxrapi[2230]: starting Mx48Router ASCII API Version: V4.5-1 (build: 27)
May 20 16:18:06 vxrouter vxrapi[2230]: Using multicast IP address 239.255.13.9
May 20 16:18:06 vxrouter vxrapi[2230]: multicast mode enabled
If broadcast is in effect, the log file will record that information.
May 20 16:35:15 vxrouter vxrapi[2268]: starting Mx48Router ASCII API Version: V4.5-1 (build: 27)
May 20 16:35:15 vxrouter vxrapi[2268]: Using broadcast IP address 192.168.13.255
If you don't want to use the default multicast address, it can specify the address you require on
the command line by adding an equal sign '=' and the IP address to the '--mcast' option. For
example: '--mcast=239.255.13.105'
The selection of a multicast address is beyond the scope of this document. You will need to
contact your IT / Networking department. The address you use may have some effect on your
network infrastructure, so contact the appropriate personal.
The API will attempt to use the multicast IP address you specify. If it can not connect to that
address, the API will faill back to using broadcast. This is also logged.
May 20 16:17:09 vxrouter vxrapi[2225]: starting Mx48Router ASCII API Version: V4.5-1 (build: 27)
May 20 16:17:09 vxrouter vxrapi[2225]: broadcast_setup() vxASCIIapi.c@5193: Error: (Cannot assign
requested address) in bind [IP address = 1.2.3.4], switching to broadcast
May 20 16:17:09 vxrouter vxrapi[2225]: Using broadcast IP address 192.168.13.255
The example above shows an attempt to use the IP address of 1.2.3.4. The API was not able to
connect to that address, so it went back to using broadcast.
Both broadcast and multicast will use UDP port 17564 to transmit the status.
Revision: G