BGP CHAPTER 12 (ROUTE-REFLECTION)

BGP CHAPTER 12 (ROUTE-REFLECTION)
QUESTION:
25b. What is Route-Reflection ?
-->Perform Lab for Route-reflection .
25b. What is Route-Reflection ?
Solution:
--> RRs Bend the BGP Split Horizon rules.
. RRs Process updates as follows:
- eBGP Peer --> All iBGP / eBGP peers.
- iBGP (non-client) Peer --> eBGP and Clients
- iBGP (client) Peer --> All Peers (Non-sender)

. RR Groups add a cluster-id attribute to routes
. RR clients are oblivious to everything .

-->Perform Lab for Route-reflection .
According to diagram:
-->

The updates for BB3 via eBGP go to the R4, R4 will forward updates via
iBGP to R1, but due to split horizon R1 will not forward updates to the R3.
Now we can make R1, BGP route-reflector then it forward the updates to
the non-client also.

R1,R4,R3, BB3 config:


!
hostname R1
!
interface Loopback1
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 10.1.14.1 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 10.1.13.1 255.255.255.0
 clock rate 2000000
!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface Serial0/1
 no ip address
 shutdown
 clock rate 2000000
!
router ospf 1
 log-adjacency-changes
 network 1.1.1.1 0.0.0.0 area 0
 network 10.1.13.0 0.0.0.255 area 0
 network 10.1.14.0 0.0.0.255 area 0
!
router bgp 100
 no synchronization
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 100
 neighbor 3.3.3.3 update-source Loopback1
 neighbor 3.3.3.3 route-reflector-client
 neighbor 4.4.4.4 remote-as 100
 neighbor 4.4.4.4 update-source Loopback1
 no auto-summary
!
ip forward-protocol nd
!
end

!

hostname R3

!

!

interface Loopback1

 ip address 3.3.3.3 255.255.255.255

!

interface FastEthernet0/0

 no ip address

 shutdown

 duplex auto

 speed auto

!

interface Serial0/0

 ip address 10.1.13.3 255.255.255.0

 clock rate 2000000

!

interface FastEthernet0/1

 no ip address

 shutdown

 duplex auto

 speed auto

!

interface Serial0/1

 no ip address

 shutdown

 clock rate 2000000

!

router ospf 1

 log-adjacency-changes

 network 3.3.3.3 0.0.0.0 area 0

 network 10.1.13.0 0.0.0.255 area 0

!

router bgp 100

 no synchronization

 bgp log-neighbor-changes

 neighbor 1.1.1.1 remote-as 100

 neighbor 1.1.1.1 update-source Loopback1

 no auto-summary

!

end

!

hostname R4

!

interface Loopback1

 ip address 4.4.4.4 255.255.255.255

!

interface FastEthernet0/0

 ip address 10.1.14.4 255.255.255.0

 duplex auto

 speed auto

!

interface FastEthernet0/1

 ip address 204.12.1.4 255.255.255.0

 duplex auto

 speed auto

!

router ospf 1

 log-adjacency-changes

 passive-interface FastEthernet0/1

 network 4.4.4.4 0.0.0.0 area 0

 network 10.1.14.0 0.0.0.255 area 0

 network 204.12.1.0 0.0.0.255 area 0

!

router bgp 100

 no synchronization

 bgp log-neighbor-changes

 neighbor 1.1.1.1 remote-as 100

 neighbor 1.1.1.1 update-source Loopback1

 neighbor 3.3.3.3 remote-as 100

 neighbor 3.3.3.3 update-source Loopback1

 neighbor 204.12.1.254 remote-as 54

 no auto-summary

!

end

hostname BB3

!

interface Loopback1

 ip address 33.1.1.1 255.255.255.255

!

interface FastEthernet0/0

 ip address 204.12.1.254 255.255.255.0

 duplex auto

 speed auto

!

interface FastEthernet0/1

 no ip address

 shutdown

 duplex auto

 speed auto

!

router bgp 54

 no synchronization

 bgp log-neighbor-changes

 network 33.1.1.1 mask 255.255.255.255

 neighbor 204.12.1.4 remote-as 100

 no auto-summary

!

end

output at R3:

R3 getting routes from R1.........WoW !!!!!!

R3#sh ip bg

BGP table version is 2, local router ID is 3.3.3.3

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

              r RIB-failure, S Stale

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

*>i33.1.1.1/32      204.12.1.254             0    100      0 54 i