cisco 200-301 dump

cisco 200-301 dump.Authentication II StandardsThis chapter describes how to implement some common management protocols and features on a router, including Network Time Protocol (NTP), Dynamic Host Configuration Protocol (DHCP), Simple Network Management Protocol (SNMP), logging, and the Cisco-specific protocol NetFlow0Authentication Target 17.01174 Network Time ProtocolThe date and time of the router is important for many reasons; here are two of the most common reasons: . Writing messages to logs; . Authentication using digital certificates. Obviously, when viewing security-related log messages, it would be helpful for forensics if they contained the correct timestamp. Determining whether a certificate on a deviceOne of the factors that determine whether a certificate is valid is within the validity period: certificates have an effective and expiration date and time. When the peer receives the certificate, it will confirm that the current time is within the validity period of the certificate. With this in mind, the date and time of the router is important. There are two ways to set the time on the device: . Manually configuring the date and time, which was discussed in Chapter 10 .. Using the Network Time Protocol (NTP) o The next few subsections describe NTP and how to configure and verify it on Cisco IOS devices.17.1.1 NTP OverviewNTP is an open standard that allows you to synchronize your router's time with a central time server, which is achieved by having the device periodically query the NTP server for the current date and time. NTP uses the User Datagram Protocol and port 123 to obtain the correct time from an internal or external server. The reliability of a server refers to the level of its clock source. The most accurate is an atomic clock, but most networks do not usually require such high accuracy and obtain the time from a GPS source.NTP provides three basic methods of transferring time messages between a time server and an NTP client.