Wednesday, 28 December 2016

BGP CHAPTER 15(Peer_groups_lab)

BGP CHAPTER 15(Peer_groups_lab)
30. What is peer-groups in BGP ?
--> Lab on BGP Peer-groups .
31. What is BGP route Dampening ?
-->
Solution:
30. What is peer-groups in BGP ?
--> Lab on BGP Peer-groups .
. Efficient way of neighbour configuration.
. Separate peer for IBGP & EBGP
. Generates a single outbound update for all the peers.
. Individual configuration supported for inbound updates.
. Handled dynamically in IOS 12.0 (show ip bgp update-gorup)

Lab:
diagram--->
R1-R5 configs:

hostname R1
!

!
interface Loopback1
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 10.1.12.1 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/1
 ip address 10.1.13.1 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 1.1.1.1 0.0.0.0 area 0
 network 10.1.12.0 0.0.0.255 area 0
 network 10.1.13.0 0.0.0.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor IBGP_PEERS peer-group
 neighbor IBGP_PEERS remote-as 1234
 neighbor IBGP_PEERS update-source Loopback1
 neighbor 2.2.2.2 peer-group IBGP_PEERS
 neighbor 3.3.3.3 peer-group IBGP_PEERS
 neighbor 4.4.4.4 peer-group IBGP_PEERS
 no auto-summary
!
end

!
hostname R2
!
!
interface Loopback1
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 10.1.12.2 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/1
 ip address 10.1.24.2 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 2.2.2.2 0.0.0.0 area 0
 network 10.1.12.0 0.0.0.255 area 0
 network 10.1.24.0 0.0.0.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor IBGP_PEERS peer-group
 neighbor IBGP_PEERS remote-as 1234
 neighbor IBGP_PEERS update-source Loopback1
 neighbor 1.1.1.1 peer-group IBGP_PEERS
 neighbor 3.3.3.3 peer-group IBGP_PEERS
 neighbor 4.4.4.4 peer-group IBGP_PEERS
 no auto-summary
!
!
end

!
hostname R3
!
interface Loopback1
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 10.1.34.3 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/1
 ip address 10.1.13.3 255.255.255.0
 duplex auto
 speed auto
!
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
 network 10.1.34.0 0.0.0.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor IBGP_PEERS peer-group
 neighbor IBGP_PEERS remote-as 1234
 neighbor IBGP_PEERS update-source Loopback1
 neighbor 1.1.1.1 peer-group IBGP_PEERS
 neighbor 2.2.2.2 peer-group IBGP_PEERS
 neighbor 4.4.4.4 peer-group IBGP_PEERS
 no auto-summary
!
end

hostname R4
!
interface Loopback1
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 10.1.34.4 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 10.1.45.4 255.255.255.0
 clock rate 2000000
!
interface FastEthernet0/1
 ip address 10.1.24.4 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/1
 no ip address
 shutdown
 clock rate 2000000
!
router ospf 1
 log-adjacency-changes
 passive-interface Serial0/0
 network 4.4.4.4 0.0.0.0 area 0
 network 10.1.24.0 0.0.0.255 area 0
 network 10.1.34.0 0.0.0.255 area 0
 network 10.1.45.0 0.0.0.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor IBGP_PEERS peer-group
 neighbor IBGP_PEERS remote-as 1234
 neighbor IBGP_PEERS update-source Loopback1
 neighbor 1.1.1.1 peer-group IBGP_PEERS
 neighbor 2.2.2.2 peer-group IBGP_PEERS
 neighbor 3.3.3.3 peer-group IBGP_PEERS
 neighbor 10.1.45.5 remote-as 555
 no auto-summary
!
end


!
hostname R5
!
!
interface Loopback1
 ip address 5.5.5.5 255.255.255.255
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 10.1.45.5 255.255.255.0
 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 bgp 555
 no synchronization
 bgp log-neighbor-changes
 network 5.5.5.5 mask 255.255.255.255
 neighbor 10.1.45.4 remote-as 1234
 no auto-summary
!
end
-------------------------------------------------

31. What is BGP route Dampening ?
-->
.Suppress the impact of flapping routes without impacting better routes.
.Default mechanish: 5 seconds 'wait' for iBGP & 30 second 'wait' for eBGP.
.Works like a water beaker:
- penalty - 1000
- Suppress limit - 2000
- Reuse limit - 750
- Decay algorithm (half-life) - 15 min

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