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EM1500 User’s Manual
35
Routers
This is where you specify the IP addresses of the routers that the EM1500 will use
when packets need to be forwarded outside of the LAN.
For most cases enter just the IP address of the router in dotted decimal form and leave
the mask and network entries zero. They are for the special case of two routers on the
same LAN. When there are two routers to choose from, the correct netmask values in
these fields allow for more efficient routing.
Name Servers
This is where you specify the IP addresses of DNS name servers. Specify IP addresses
in dotted decimal form.
Connection keepalive(s)
If a non-zero value is entered, TCP keepalives will be used to maintain the network
connection. A keepalive segment will be sent at the specified time interval (in
seconds). This allows a unit to recognize that the peer has terminated its end of the
connection without the usual notification. Note that use of this option will increase
network traffic.
Secure config
The EM1500 may be configured to use cryptography to prevent unauthorized changes
to the configuration. This protection only applies to configuration. The unit does not
currently support any protection of the data connections. Secure configuration is rec-
ommended if the EM1500 is to be connected to an Ethernet network which is accessi-
ble from the general Internet. It is not required if the unit is behind a firewall, or on an
isolated network, unless it is desired to protect the unit from other network users.
You enable secure configuration by checking the “Secure config” check box. When
you save the configuration to the target unit, you will see the unit's icon change from a
red open padlock to a green closed padlock. The configuration program running on
the PC generates a random key. The key is sent to the unit, and also stored in a file on
the PC. The key in the file is associated with the serial number (MAC address) of the
unit. Each unit will have a unique key.
Since all keys are stored in the file on the PC, it is critical to prevent unauthorized
users from accessing this file, and it is also critical that the file not be lost or deleted.
Once a unit is configured for secure configuration, it is not possible to reconfigure the
unit unless the key file is located and has the correct key. If the key is lost, then the
only alternative is to physically go and reset the unit to factory defaults.
Summary of Contents for EM1500
Page 14: ...10 www rabbit com Introduction...
Page 22: ...18 www rabbit com Getting Started...
Page 76: ...72 www rabbit com EM1500 Configuration...
Page 90: ...86 www rabbit com EM1500 Specifications...
Page 104: ...100 www rabbit com Serial and TCP Protocols...
Page 118: ...114 www rabbit com EM1500 FAQ...