38.BGP - eBGP, iBGP

2023.03.13 - [분류 전체보기] - 37.BGP

37.BGP

router bgp [as number]
bgp router-id [ id ]
neighbor [ 연결된 next hope network ] remote-as [as number]
network [알려줄 network 주소/보통 회사쪽 네트워크만] mask [subnetmask]

<R1>
router bgp 100
bgp router-id 1.1.1.1
neighbor 1.1.12.2 remote-as 100
network 192.168.10.0 mask 255.255.255.0

<R2>
router bgp 100
bgp router-id 2.2.2.2
neighbor 1.1.12.1 remote-as 100
network 192.168.20.0 mask 255.255.255.0

<R3>
router bgp 200
bgp router-id 3.3.3.3
neighbor 3.3.12.2 remote-as 200
network 192.168.30.0 mask 255.255.255.0

<R4>
router bgp 200
bgp router-id 4.4.4.4
neighbor 3.3.12.1 remote-as 200
network 192.168.40.0 mask 255.255.255.0

#show ip bgp 결과

⇒ 각각의 as 끼리 bgp로 연결되어 졌습니다.

<R2>

router bgp 100 neigbor 2.2.12.2 remote-as 200

<R3>

router bgp 200

neigbor 2.2.12.1 remote-as 100

⇒ bgp as끼리 연결해주는 명령어를 적어줍니다.

명령어 추가 후 #show ip bgp 결과

bgp로 분배된것은 B로 표시되어집니다.

 

IBGP(AD 값 : 200, TTL : 255) → 다른 as에서 받는 것

eBGP(AD : 20 ,TTL : 1 ) → 다른 as에 닿아있는 Router DMZ구간(누구의 소유가 아닌 구간)

R1은 iBGP 로 다른 as에서 받은 것들은 ad 200 을 갖는다.

R2는 as 100 ,as 200 이 맞닿아있는 곳이므로 eBGP DMZ구간으로 ad 20을 갖는다.

 

 

#show ip bgp summary

R1에서 show ip bgp summary

 

⇒ neighbor의 주소를 보여줍니다.

<R1>
router bgp 100
bgp router-id 1.1.1.1
neighbor 2.2.2.2 remote-as 100
neighbor 2.2.2.2 update-source lo 0
network 192.168.10.0 mask 255.255.255.0

<R2>
ip route 3.3.3.0 255.255.255.0 2.2.12.2
router bgp 100
bgp router-id 2.2.2.2
neighbor 1.1.1.1 remote-as 100
neighbor 1.1.1.1 update-source lo 0
neighbor 3.3.3.3 remote-as 200
neighbor 3.3.3.3 update-source lo 0
neighbor 3.3.3.3 ebgp-multihop 2
network 192.168.20.0 mask 255.255.255.0

<R3>
ip route 2.2.2.0 255.255.255.0 2.2.12.1

router bgp 200
bgp router-id 3.3.3.3
neighbor 4.4.4.4 remote-as 200
neighbor 4.4.4.4 update-source lo 0
neighbor 2.2.2.2 remote-as 100
neighbor 2.2.2.2 update-source lo 0
neighbor 2.2.2.2 ebgp-multihop 2
network 192.168.30.0 mask 255.255.255.0

<R4>

router bgp 200
bgp router-id 4.4.4.4
neighbor 3.3.3.3 remote-as 200
neighbor 3.3.3.3 update-source lo 0 
network 192.168.40.0 mask 255.255.255.0

<R1>
router bgp 100
bgp route-id 1.1.1.1
neighbor 1.1.12.2 remote-as 100
network 192.168.10.0 mask 255.255.255.0


<R2>
router bgp 100
bgp router-id 2.2.2.2
neighbor 1.1.12.1 remote-as 100
network 192.168.20.0 mask 255.255.255.0
neighbor 2.2.12.2 remote-as 200

<R3>
router bgp 200
bgp router-id 3.3.3.3
neighbor 3.3.12.2 remote-as 200
network 192.168.30.0 mask 255.255.255.0
neighbor 2.2.12.1 remote-as 100


<R4>
router bgp 200
bgp router-id 4.4.4.4
neighbor 3.3.12.1 remote-as 200
network 192.168.40.0 mask 255.255.255.0
neighbor 4.4.12.2 remote-as 300

<R5>
router bgp 300
bgp router-id 5.5.5.5
neighbor 5.5.12.1 remote-as 300
network 192.168.50.0 mask 255.255.255.0
neighbor 4.4.12.1 remote-as 200

<R6>
router bgp 300
bgp router-id 6.6.6.6
neighbor 5.5.12.2 remote-as 300
network 192.168.60.0 mask 255.255.255.0
neighbor 6.6.12.2 remote-as 400

<R7>
router bgp 400
bgp router-id 7.7.7.7
neighbor 6.6.12.1 remote-as 300
network 192.168.70.0 mask 255.255.255.0
neighbor 7.7.12.2 remote-as 400

<R8>
router bgp 400
bgp router-id 8.8.8.8
neighbor 7.7.12.1 remote-as 400
network 192.168.80.0 mask 255.255.255.0

<R1>
router eigrp 100
 network 1.1.12.0 0.0.0.255
!
router bgp 100
 network 192.168.10.0
 neighbor 192.168.20.1 remote-as 100
 neighbor 192.168.20.1 update-source Loopback0
!
ip route 192.168.20.0 255.255.255.0 1.1.12.2
ip route 192.168.30.0 255.255.255.0 1.1.12.2

<R2>
router eigrp 100
 network 1.1.12.0 0.0.0.255
 network 2.2.12.0 0.0.0.255
!
router bgp 100
 network 192.168.20.0
 neighbor 192.168.10.1 remote-as 100
 neighbor 192.168.10.1 update-source Loopback0
 neighbor 192.168.30.1 remote-as 200
 neighbor 192.168.30.1 ebgp-multihop 2
 neighbor 192.168.30.1 update-source Loopback0

ip route 192.168.10.0 255.255.255.0 1.1.12.1
ip route 192.168.30.0 255.255.255.0 2.2.12.2

<R3>
router ospf 1
 network 2.2.12.0 0.0.0.255 area 0
 network 3.3.12.0 0.0.0.255 area 0
!
router bgp 200
 network 192.168.30.0
 neighbor 192.168.20.1 remote-as 100
 neighbor 192.168.20.1 ebgp-multihop 2
 neighbor 192.168.20.1 update-source Loopback0
 neighbor 192.168.40.1 remote-as 200
 neighbor 192.168.40.1 update-source Loopback0
!
ip route 192.168.20.0 255.255.255.0 2.2.12.1
ip route 192.168.40.0 255.255.255.0 3.3.12.2

<R4>
router ospf 1
 network 3.3.12.0 0.0.0.255 area 0
!
router bgp 200
 network 192.168.40.0
 neighbor 192.168.30.1 remote-as 200
 neighbor 192.168.30.1 update-source Loopback0
!
ip route 192.168.20.0 255.255.255.0 3.3.12.1
ip route 192.168.30.0 255.255.255.0 3.3.12.1