Day 24 - Dynamic Routing

Network route

• route with a mask length < 32

  • route to a whole subnet

Host Route

route to a specific host

Configure a route to a specific host

• ip route 192.168.1.1 255.255.255.255

the 255.255.255.255 is /32

dynamic routing definition

• use dynamic routing protocols to advertise information about the routes they know to other routes

• form ‘Adjacencies/neighbor relationships'

lower metric =

superior

in spanning-tree the lower root cost

superior

dynamic routing protocols can be divided into two main categories

• IGP

• EGP (exterior gateway protocol)

IGP

• interior gateway protocol → share routes within a single AS (autonomous system) remember in OSPF the ABR (area border router)

OSPF is a

IGP

BGP is the only

EGP used in modern networks

IGP have two types

distance vector and link state

Distance vector protocols operate by sending ___ to their directly connected neighbors

• known destination networks

  • metric to reach their known destination

why is it called routing by rumor in Distance Vector

routers don’t know beyond their neighbors, it only knows the information it’s neighbors tell it

Link-state creates a

connectivity map (it requires more power to run, but it is faster)

each router gets a whole picture of the network

ECMP

equal cost multi-path

when traffic is load-balanced along both routes

ECMP

metric for rip, eigrp, ospf, is-is

• rip → hop

• eigrp → metric based on bandwidth and delay

• ospf → cost

• is-is→ cost (10 by default)