289NslookupA utility used to find the IP address or host name of a machine ona network. To use the nslookup command on the VPN Gateway,it must have been configured to use a DNS server.NTP (Network Time Protocol)A protocol used to synchronize the real-time clock in a computer.There are numerous primary and secondary servers on theInternet that are synchronized to the Coordinated Universal Time(UTC) through radio, satellite or modem.NVGNortel VPN Gateway.PassphrasePassphrases differ from passwords only in length. Passwords areusually short, from six to ten characters. Short passwords may beadequate for logging onto computer systems that are programmedto detect a large number of incorrect guesses, but they are notsafe for use with encryption systems. Passphrases are usuallymuch longer—up to 100 characters or more. Their greater lengthmakes passphrases more secure.PEM (Privacy Enhanced Mail)A standard for secure e-mail on the Internet. It supportsencryption, digital signatures and digital certificates as well asboth private and public key methods. Keys and certificates areoften stored in the PEM format.Ping (Packet INternet Groper)A utility used to determine whether a particular IP address isonline.PKCS12A standard for storing private keys and certificates.PKI (public key infrastructure)Short for public key infrastructure, a system of digital certificates,Certificate Authorities, and other registration authorities that verifyand authenticate the validity of each party involved in an Internettransaction. PKIs are currently evolving and there is no singlePKI nor even a single agreed-upon standard for setting up a PKI.However, nearly everyone agrees that reliable PKIs are necessarybefore electronic commerce can become widespread.A PKI is also called a trust hierarchy.Nortel VPN GatewayUser GuideNN46120-104 02.01 Standard14 April 2008Copyright © 2007-2008 Nortel Networks.
