IP Routing and Dynamic Routing Protocols Lecture Notes

Comprehensive vocabulary flashcards covering IP routing types (Static, Default, Dynamic), major routing protocols (RIP, OSPF, IS-IS), and their specific terminologies and mechanisms.

Static Routes

Routes that are manually configured by network administrators, have low system requirements, and apply to simple, stable, and small networks.

Default Routes

Used only when packets to be forwarded do not match any routing entry in an IP routing table; it is the route to network $0.0.0.0$ with the mask $0.0.0.0$.

Dynamic Routing Protocols

Protocols that automatically discover and generate routes, and update them when the topology changes, reducing the workload of network administrators in large networks.

Autonomous Systems (AS)

A collection of networks and subnetworks that is independent of another, can have its own routing algorithm, and can be managed independently.

Interior Gateway Protocol (IGP)

A routing protocol meant to dynamically route data across a network that is fully controlled and maintained by the administrator, such as RIP, OSPF, or IS-IS.

Exterior Gateway Protocol (EGP)

Routing protocols used to exchange routes between distinctly separate networks that an administrator has no control over, with BGP being the most common example.

Least-cost path

A routing algorithm objective that finds a path between the source and destination with the minimum cost.

Shortest path

A routing algorithm objective where the path has the smallest number of links between the source and destination.

Distance-Vector Routing Protocol

A type of routing where all routers send their routing tables only to their neighboring routers periodically to learn routes and update their own tables.

Routing Information Protocol (RIP)

A distance-vector IGP that uses a hop count as the route cost, has a preference of $100$, and is designed for networks with a maximum of $15$ hops.

Hop count

The number of routers through which a packet passes to reach its destination, used by RIP as its routing metric.

Link-State Routing Protocol

A type of routing where each router sends the state of its own interfaces to all other routers only when there is a change to report, using the information to recalculate best paths.

Link-State Advertisement (LSA)

An OSPF data packet containing link-state and routing information that is shared with other routers.

Link-State Database (LSDB)

A collection of all LS PDUs originated from the area's routers; two routers interfacing the same area must have identical LSDBs.

Shortest Path First (SPF) Algorithm

An algorithm used by routers to calculate a loop-free tree with itself as the root and the shortest path to each corner of a network based on LSDB information.

Open Shortest Path First (OSPF)

A link-state routing protocol developed by the IETF in $1988$ capable of quickly detecting topological changes and establishing loop-free routes using costs as metrics.

HELLO packet

A special data packet sent periodically from an OSPF router to establish and confirm network adjacency relationships to other routers.

IS-IS (Intermediate System-to-Intermediate System)

A link-state protocol that uses Dijkstra’s algorithm to find the best path, exchanges link-state packets, and forms neighbor adjacencies.

Intermediate System (IS)

The ISO name for a router in the context of IS-IS terminology.

End System (ES)

The ISO name for a device on the network, such as a server or workstation, known as hosts.

NSAP (Network Service Access Point)

A Layer-$3$ address for CLNS packets used in IS-IS for communication, functioning similarly to an IP address.

Level 1 Router (IS-IS)

A router in a normal area that does not connect to another area and only shares routing information with other Level $1$ routers.

Level 2 Router (IS-IS)

A backbone router that does not connect to other areas, only shares information with other Level $2$ routers, and tracks routing between areas.

Level 1-2 Router (IS-IS)

A router in a normal or backbone area that connects different areas together and takes part in both Level $1$ and Level $2$ routing.

Route Leaking

A technique in IS-IS used to optimize routing by leaking routes from the Level $2$ database into the Level $1$ database to prevent suboptimal routing outside the area.