TRENDnet TEG-S4000I - Manual (Page 31)

Secure IP for Telnet and HTTP
The IP security is for Telnet and HTTP , if device is installed in a
internet environment , switch may be attach by Hacker, then the
system maybe will crash, for prevent this status, you can enable the
function and setting the IP address, it provides four IP address, only
authorized IP address can manage device.
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