Thinklogical Configuring the TLX ASCII Interface - Manual (Page 13)

®
Configuring the TLX ASCII Interface 10 Rev. A - July, 2015
Using ‘Multicast’ to Send Switch Status Instead of ‘Broadcast’
The API has a command line option for using a network multicast address instead of a
broadcast address to deliver switch status messages. The default mode of the API will
broadcast its status over the network. The use of a multicast address allows these
messages to be routed to other network segments.
The command line option to enable multicast is '--mcast'. Without 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.
imxs tlxapi[9389]: Using multicast IP address 239.255.13.9
imxs tlxapi[9389]: multicast mode enabled
If broadcast is in effect, the log file will record that information.
imxs tlxapi[9389]: Using broadcast IP address 192.168.13.255
If you prefer to not use the default multicast address, you can specify the preferred address on
the command line by adding an equal sign '=' and the IP address to the '--mcast' option. For
example: '--mcast=239.255.13.105'.
____________________________________________________________________________
Warning! The selection of a multicast address is beyond the scope of this
document, in which case, you may need to contact your IT / Networking department.
The address you use may have some effect on your network infrastructure, so be
sure to contact the appropriate, qualified personnel.
____________________________________________________________________________
The API will attempt to use the specified multicast IP address. If it cannot connect to that
address, the API will fall back to using broadcast. This is also logged.
The example below 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.
imxs tlxapi[9389]: broadcast_setup() vxASCIIapi.c@5193: Error: (Cannot assign requested address)
in bind [IP address = 1.2.3.4], switching to broadcast
imxs tlxapi[9389]: Using broadcast IP address 192.168.13.255
Both broadcast and multicast will use UDP port 17564 to transmit the status.