BGP Synchronization
The Basic Question >>Why an IGP is necessary to support IBGP and why SYNC is necessary b/w IGP and IBGP .
Lets take rule of SYNCHRONIZATION
A BGP router with synchronization enabled will not advertise its iBGP learned routes to its eBGP peers unless it has learned or verified this route on its routing table through an IGP.
In above Topology ,
R1 R2 R3 R4 are running OSPF as IGP
R1 and R2 are IBGP Peer
R1 R5 and R2 R6 are Ebgp peer respectively.
Lets Have the config of each router
======================================================================
CONFIGURATION
=====================R1=====================
int fas1/0
no sh
ip add 9.9.15.1 255.255.255.0
!
int fas0/0
no sh
ip add 9.9.14.1 255.255.255.0
!
int lo0
ip add 9.9.0.1 255.255.255.255
!
router ospf 9
router-id 9.9.0.1
network 9.9.14.1 0.0.0.0 area 0
network 9.9.0.1 0.0.0.0 area 0
=====================R2=====================
int fas1/0
no sh
ip add 9.9.26.2 255.255.255.0
!
int fas0/1
ip add 9.9.23.2 255.255.255.0
no sh
!
int lo0
ip Continue reading

