Security zone Consists of a group of interfaces to which a policy can be applied. Grouping interfaces into zones involves two steps. First, a zone must be created so that interfaces may be attached to it. Second, an interface must be configured to be a member of a given zone.

SHA-1 Secure Hash Algorithm 1. One of five cryptographic hash functions known as SHA hash functions. They were designed by the National Security Agency (NSA) and published by the National Institute of Standards and Technology (NIST) as a U.S. Federal Information Processing Standard. SHA-1 computes a fixed-length digital representation (a message digest) from an input data sequence (the message) of any length.

Signature definition file (SDF) A database of signatures used to identify malicious traffic. Modern routers typically ship with an SDF file installed in flash memory. However, the administrator usually needs to periodically update the router’s SDF, because Cisco routinely updates these files to address emerging threats.

Simple Network Management Protocol (SNMP) A management protocol that allows an SNMP manager to collect information from an SNMP agent.

Skinny Client Control Protocol (SCCP) A Cisco-proprietary signaling protocol often called Skinny protocol. SCCP is often used for signaling between Cisco IP Phones and Cisco Unified Communications Manager servers. However, some Cisco gateways also support SCCP. SCCP is considered a client/server protocol, such as MGCP and H.248.

Small Computer Systems Interface (SCSI) In terms of SAN networking, the SCSI communications model serves as the basis for all the major SAN transport technologies. In fact, you could say that a SAN can best be described as the merging of SCSI and networking.

SNMP agent A piece of software that runs on a managed device (such as a server, router, or switch).

SNMP GET A message that is used to retrieve information from a managed device

SNMP manager Runs a network management application. Sometimes called a Network Management Server (NMS).

SNMP SET A message that is used to set a variable in a managed device or to trigger an action on the managed device.