Routing Protocol Acronyms

Question 1

AS

Answer 1

Autonomous System

Question 2

BGP

Answer 2

Border Gateway Protocol

An Exterior Gateway Protocol (EGP). It allows Autonomous Systems (AS’s) to be able to discover each other.

Path Vector | Neither Link-State nor Distance Vector

It’s pretty much the only EGP in use today, and it’s what makes the Internet work.

Question 3

EGP

Answer 3

Exterior Gateway Protocol
Includes BGP

Question 4

EIGRP

Answer 4

Enhanced Interior Gateway Routing Protocol (Cisco)

Metric = Bandwidth + Delay

Hybrid | Not Link-State or Distance Vector, more like Advanced Distance Vector

Question 5

GLBP

Answer 5

Gateway Load Balancing Protocol (Cisco)

Similar to HSRP and VRRP for redundancy, but also provides load balancing capabilities.

Question 6

HSRP

Answer 6

Hot Standby Router Protocol (Cisco)

Has an active router and a passive router on standby in case the active router goes down.

Question 7

IGP

Answer 7

Interior Gateway Protocol
Includes RIP, RIPv2, OSPF, EIGRP, and IS-IS

Question 8

IS-IS

Answer 8

Intermediate System to Intermediate System

Link-State
Dijkstra’s algorithm

Question 9

OSPF

Answer 9

Open Shortest Path First

Link-State
Dijkstra’s Algorithm

Metric = Bandwidth

Question 10

RIP

Answer 10

Routing Information Protocol

Distance Vector
Slow convergence

RIPv1 - Classful
RIPv2 - Classless

Question 11

RIPv2

Answer 11

Routing Information Protocol version 2

Distance Vector
Sends entire routing table every 30 seconds.
Slow convergence.

RIPv1 - Classful
RIPv2 - Classless

Question 12

VRRP

Answer 12

Virtual Router Redundancy Protocol

Just like Hot Standby Routing Protocol, but is an open standard. Has a master router and a backup router.

Question 13

FHRP

Answer 13

First Hop Redundancy Protocol

Provides a virtual IP to use as a default gateway that multiple routers can share. This can be done to have a standby default gateway if the original goes down, or with GLBP it can also provide load balancing functions.

Question 14

Distance Vector

Answer 14

Routers share their entire routing table with neighbors at regular intervals.
They make decisions based on how many hops (or other simple metrics) it takes to reach a destination.

Question 15

Link-State

Answer 15

Routers exchange information about directly connected links and build a complete topology map of the network.
They use algorithms like Dijkstra’s to calculate the shortest path.