An example of configuring NTP authentication is shown below:
Router1(config)#ntp authentication-key 2 md5 itexamanswers
Router1(config)#ntp authenticate
Router1(config)#ntp trusted-key 2

Locator ID Separation Protocol (LISP) is a network architecture and protocol that implements the use of two namespaces instead of a single IP address:
+ Endpoint identifiers (EIDs)--assigned to end hosts.
+ Routing locators (RLOCs)--assigned to devices (primarily routers) that make up the global routing system.
Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_lisp/configuration/xe-3s/irl- xe-3s-book/irl-overview.html

3 dB of gain = +3 dB = doubles signal strength (Let's say, the base is P. So 10*log10(P/P)= 0 dB and 10*log10(2P/P) = 10*log10(2) = 3dB -> double signal)