Saturday, February 7, 2009
session 2 :
sat feb 07 2k9
network types:
broadcast
non-broadcast
point to point
point to multipoint
point to multipoint non broadcast
loopback
types of behaviour:
unicast / multicast
DR / BDR election
next-hop address
network types :
(A) broadcast :
network type is default in networks such as ethernet
hello packets are sent out using multicast
Election of dr and bdr takes place and decides the two multicast address distribution
multicast reserved addresses
224.0.0.5
224.0.0.6
DR / BDR:
The primary use of bdr is to minimise lsa replication
DR is elected based on two components : priority and router-id
Priority
0-255 ---> can be defined manually .. higher the number higher is the priority
value of '0' will make the router never to participate in election process
Router Id
Highest loopback addr and if not then highest interface ip
Can be manually set
if we have a bunch of loopbacks the higher one is selected
Interface preference :
loopback (higher ip addr) > loopback > interface addr (higher addr) > interface addr