Introduction 21Command Line InterfaceCommand Line Interface (CLI) syntax and semantics conform as much as possible to common industrypractice. CLI is composed of mandatory and optional elements. The CLI interpreter provides commandand keyword completion to assist user and shorten typing.SyslogSyslog is a protocol that allows event notifications to be sent to a set of remote servers, where they can bestored, examined and acted upon. Multiple mechanisms are implemented to send notification ofsignificant events in real time, and keep a record of these events for after-the-fact usage.For more information on Syslog, see "Managing Logs" on page 93.SNTPThe Simple Network Time Protocol (SNTP) assures accurate network device clock time synchronizationup-to the millisecond. Time synchronization is performed by a network SNTP server. Time sources areestablished by Stratums. Stratums define the distance from the reference clock. The higher the stratum(where zero is the highest), the more accurate the clock.For more information, see "Configuring SNTP Settings" on page 81.TracerouteTraceroute enables discovering IP routes that packets were forwarded along during the forwardingprocess. The CLI Traceroute utility can be executed from either the user-exec or privileged modes.802.1ab (LLDP-MED)The Link Layer Discovery Protocol allows network managers to troubleshoot and enhance networkmanagement by discovering and maintaining network topologies over multi-vendor environments.LLDP discovers network neighbors by standardizing methods for network devices to advertisethemselves to other systems, and to store discovered information. The multiple advertisement sets aresent in the packet Type Length Value (TLV) field. LLDP devices must support chassis and port IDadvertisement, as well as system name, system ID, system description, and system capabilityadvertisements.LLDP Media Endpoint Discovery (LLDP-MED) increases network flexibility by allowing differentIP systems to co-exist on a single network LLDP. It provides detailed network topology information,emergency call service via IP Phone location information, and troubleshooting information.Security FeaturesSSLSecure Socket Layer (SSL) is an application-level protocol that enables secure transactions of datathrough privacy, authentication, and data integrity. It relies upon certificates and public and private keys.
