Routing table can be managed by 2 different methods
Distance
Vector
·
RIP, IGRP
·
It doesn’t have all routing information which
saves memory and structure of table is very straight-forward
·
Even if no changes in the routing table, it
automatically updating the routing table which causes increase in traffic and
high CPU usage in the router.
·
Convergence time is longer than Link State
·
Best for small business
Link State
·
OSPF
·
One Router of the network has all routing
information
·
Find the best route based on the Shortest Path
First algorithm
·
Information sharing takes place only whenever
there is a change
·
Best for medium or higher business
Problem of
Distance Vector
·
One specific router has all routing information
·
Looping
·
Long convergence time
Solutions
for Looping
·
Maximum Hop Count is 15
·
Hold Down Timer
·
Split Horizon – A router will not advertise a
route back onto the interface from which it was learned. Split horizon is
enabled on interfaces by default.
·
Route Poisoning – When a router detects that one
of its directly connected routes has failed, it will advertise a failed route
with an infinite metric (“poisoning the route”). Routers who receive the
routing update will consider the route as failed and remove it from their routing
tables.
·
Poison Reverse