<Jeremy's IT Lab> Day 24: Dynamic Routing

Dynamic Routing

: find best destination dynamically

-> advertise info about route they know to other Router

-> form adjacent router to exchange info

-> determines superior route (lowest)

 

Types of Dynamic Routing / Algorithm type:

- IGP(Interior Gateway Protocol) : within single Autonomous System (AS), single organization(e.i. company)

   1. Distance Vetor

       (1) RIP (Routing Information Protocol)

       (2) EIGRP (Enhanced Interior Gateway Routing Protocol)

    2. Link State 

       (1) OSPF (Open Shortest Path First)

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

 

- EGP(Exterior Gateway Protocol) : used share Router btw diff AS

    1. Path Vector

       (1) BGP (Border Gateway Protocol)

 

 

1. Distance Vetor:

-> sending their know ndestin NW, meric to reach their known NW

-> 'routing by rumor' : doesn't know NW beyond its neighbors (only know neighbors)

 

2. Link State:

-> every routers create 'connectivity map'

-> advertise info until all Routers develop the same map

-> use more resources, faster reacting to changes in NW

 

** if route exact the smae metrics, load both routes in table

=> ECMP (Equal Cost Multi Path)

Algorithm type	Metric	Contents
RIP	hop count	links of all speed are equal
EIGRP	metric based BW & delay	slowest link in Router or delay
OSPF	Cost	cost calculate based on BW
IS-IS	cost	not auto cal by BW (like RIP) default 10

 

Administrative Distance(AD):

-> lower AD is preferred 

-> can't compare diff protocols

-> generally us OSPF or EIGRP

-> rarely use both protocol

protocol/type	AD
Directly connected	0
Static	1
External BGP (eBGP)	20
EIGRP	90
IGRP	100
OSPF	110
IS-IS	115
RIP	120
EIGRP (external)	170
Internal BGP (iBGP)	200
Unsuable route	255