Master Routing - AMX NETLINX PROGRAMMING LANGUAGE Manual

Master-To-Master (M2M)

Master Routing

Master routing primarily involves the communication of routing tables between masters. Routing tables
are exchanged between masters upon their initial connection, and updates to the routing tables are
exchanged as the connections change.
NetLinx masters do not automatically connect to other NetLinx masters by virtue of being on the same
network. The URL List of the NetLinx master is used to force the master to initiate a TCP connection to
the specified URL/IP address. Therefore, the first step in assembling an M2M system is to setup the
URL in at least one of the masters to point to the other master. For example, in FIG. 1 NetLinx Master
System #1 could have its URL set with a single entry that contains the IP address of the NetLinx Master
System #7.
Note that any TCP/IP device, including NetLinx masters, that utilizes DHCP to obtain its TCP/IP
configuration are subject to having their IP address change at any time. Therefore, a NetLinx master's IP
address must be static, unless the network supports Dynamic DNS and a DHCP server capable of
updating the DNS tables on behalf of the DHCP client. If Dynamic DNS/DHCP servers are available, the
NetLinx master's host name may be used in the URL list. As of this writing, only Windows 2000's DNS
server/DHCP servers support the required dynamic capabilities.
Once the systems are connected, they exchange routing information so each master will learn about all
the masters connected to the other. As a diagnostic aid, the "show route" command can be issued from a
Telnet session to show how masters are connected to each other. Consider the following system of
interconnected NetLinx masters:
NetLinx Master
System #1
192.168.12.105
NetLinx Master
System #2
192.168.12.76
NetLinx Master
System #5
192.168.12.79
NetLinx Master
System #4
192.168.12.80
FIG. 2 System of interconnected NetLinx Masters
In FIG. 2, arrows depict the direction of the initiated connection. I.e. System #1 initiated the connection
to System #2 by having the IP address of System #2 in its URL List.
The following sample output is from a Telnet session connected to System #5. The connection of the
NetLinx system is depicted in FIG. .
>show route
System
-----------------------------------------
1
2
3
4
->5
106
111
92
NetLinx Master
System #3
192.168.12.105
NetLinx Master
System #106
192.168.12.106
Route Metric
2 2
2 1
2 2
4 1
5 0
106 1
106 2
NetLinx Master
System #111
192.168.12.105
PhyAddress
TCP Socket=18 IP=192.168.12.76 Index=3
TCP Socket=18 IP=192.168.12.76 Index=3
TCP Socket=18 IP=192.168.12.76 Index=3
TCP Socket=16 IP=192.168.12.80 Index=1
AXlink
TCP Socket=19 IP=192.168.12.106 Index=2
TCP Socket=19 IP=192.168.12.106 Index=2
NetLinx Programming Language Reference Guide