| Term | Definition |
| AS | A collection of networks under a common administration sharing a common routing strategy. Autonomous systems are subdivided by areas. An autonomous system must be assigned a unique 16-bit number by the IANA (Cisco Systems, Inc. 2001). |
| BGP | Border Gateway Protocol. Inter-domain routing protocol that replaces EGP. BGP exchanges reachability information with other BGP systems. It is defined by RFC 1163 (Cisco Systems, Inc. 2001). |
| Centralized Routing | Routes are computed centrally by a designated central router and thereafter periodically distributed to all routers in a given subnet (Banerjee 2004). |
| Distributed Routing | Routing choices are made locally, in a collaborative / pre-planned manner (Banerjee 2004). |
| IANA | Internet Assigned Numbers Authority. Organization operated under the auspices of the ISOC as a part of the IAB. IANA delegates authority for IP address-space allocation and domain-name assignment to the InterNIC and other organizations. IANA also maintains a database of assigned protocol identifiers used in the TCP/IP stack, including autonomous system numbers (Cisco Systems, Inc. 2001). |
| ICMP | Internet Control Message Protocol. A protocol within TCP/IP mainly used to report errors in datagram transmission. Interpreted in the TCP/IP PI suite. |
| Term | Definition |
| IGMP | Internet Control Message Protocol. Network layer Internet protocol that reports errors and provides other information relevant to IP packet processing. Documented in RFC 792 (Cisco Systems, Inc. 2001). |
| IGRP | Interior Gateway Routing Protocol. IGP developed by Cisco to address the issues associated with routing in large, heterogeneous networks (Cisco Systems, Inc. 2001). |
| IPX | Internetwork Packet Exchange. NetWare network layer (Layer 3) protocol used for transferring data from servers to workstations. IPX is similar to IP and XNS (Cisco Systems, Inc. 2001). |
| IS-IS | Intermediate System-to-Intermediate System. OSI link-state hierarchical routing protocol, where ISs (routers) exchange routing information based on a single metric to determine network topology (Cisco Systems, Inc. 2001). |
| OSPF | Open Shortest Path First. Link-state, hierarchical IGP routing algorithm proposed as a successor to RIP in the Internet community. OSPF features include least-cost routing, multipath routing, and load balancing. OSPF was derived from an early version of the IS-IS protocol (Cisco Systems, Inc. 2001). |