Westermo MR Series - Manual (Page 47)

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Web Interface and Command Line Reference Guide www.westermo.com
Confi gure > Backup IP Addresses 4.8
This page contains a table that is used to specify alternative addresses to use when the unit fails in
an attempt to open a socket. These addresses are used only for socket connections that originate
from the unit and are typically used to provide back-up for XOT connections, TANS (TPAD answer-
ing) con nections or any application in which the unit is making outgoing socket connections.
When a back-up address is in use, the original IP address that failed to open is tested at intervals to
check if it has become available again. Additionally, at the end of a session, the unit will remember
when an IP address has failed and use the back-up IP address immediately for future connections.
When the original IP address eventually becomes available again, the unit will automatically detect
this and revert to using it.
Using the Web Page(s)
The web page contains a table with four columns headed:
IP Address:
In this column you should enter the original IP address to which the backup address relates.
Backup IP Address: This is the backup address to try when the unit fails to open a connection to
IP Address.
Retry Time (s):
The is the length of time seconds that the unit will wait between checks to see if a connection
can yet be made to IP Address.
Try Next:
In the case that a connection to the primary IP address has just failed, this parameter deter-
mines whether a connection to the backup IP address should be attempted immediately or
when the application next attempts to open a connection.
When set to “Yes” the socket will attempt to connect to the backup IP address immediately
after the connection to the primary IP address failed and BEFORE reporting this failure to the
calling application, e.g. TPAD. If the backup is successful this means the application will not expe-
rience any kind of failure even though the unit has connected to the backup IP address.
When set to “No” the socket will report the failure to connect back to the calling applica-
tion imme diately after the connection to the primary IP address has failed. The unit will not
try to connect to the backup IP address at this stage. The next time the application attempts
to connect to the same IP address, the unit will instead automatically connect to the backup IP
address.
Chaining IP Addresses
It is possible to chain backup IP addresses by making multiple entries in the table.
For example the following table with 3 rows populated will cause the router to back-up from
192.168.0.1 to 192.168.0.2 and then to 192.168.0.3 and then to 192.168.0.4 (if necessary).
Note:
The length of time that it takes for a connection to an IP address to fail is determined by the
TCP socket connect timeout parameter on the Configure > General web page