A facility available for Cisco routers that enables one host to contact another host through a firewall. It grants access on a per-user basis.
"Cisco lock and key." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/cisco-lock-and-key>.
Cisco lock and key. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/cisco-lock-and-key