ECE495 Chapter Notes - Chapter 3: Connectionless-Mode Network Service, Private Network, Routing Protocol
Document Summary
Is-is (intermediate system -to- intermediate system) is a standardized link-state protocol that was developed to be the definitive routing protocol for the osi (open systems interconnect) model, which was developed by. Though it was designed as an interior gateway protocol (igp), is-is is predominantly used by isps, due to its scalability. Is-is additionally has three optional metrics: delay, expense, and error. Cisco does not support these optional metrics: is-is has no hop-count limit. Is-is is only available on enterprise versions of the cisco ios. Is-is was originally developed to route iso clnp addresses (outlined in. Thus, is-is was modified to additionally support ip routing, and became. Integrated (or dual) is-is (outlined in rfc 1195). The is-is clnp address is hexadecimal and of variable length, and can range from 64 to 160 bits in length. Sections, including: area field (variable length, id field (from 8 to 64 bits, though usually 48 bits, selector (sel) field - (8 bits)