Cần giúp đỡ BGP
Chào mọi người,
Mình có 1 thắc mắc nhờ mọi người giúp đỡ. Xem hình bài Lab.
Cấu hình như sau:
Aspen#show run | begin router
router bgp 300
no synchronization
bgp log-neighbor-changes
neighbor 192.168.1.221 remote-as 100
no auto-summary
Vail#sho run | begin router
router bgp 100
no synchronization
bgp log-neighbor-changes
neighbor 192.168.1.222 remote-as 300
neighbor 192.168.1.225 remote-as 200
no auto-summary
Taos#sho run | begin router
router eigrp 200
passive-interface Serial1/0
network 192.168.1.0
network 192.168.100.0
auto-summary
!
router bgp 200
no synchronization
bgp log-neighbor-changes
redistribute eigrp 200
neighbor 192.168.1.226 remote-as 100
no auto-summary
AngelFire#sho run | begin router
router eigrp 200
network 192.168.1.0
network 192.168.200.0
auto-summary
Theo mình hiểu thì để BGP router quảng bá IGP route đến eBGP peer thì phải distribute IGP route vào BGP hoặc dùng network command để quảng bá. Còn eBGP router sẽ quảng bá routes tự động cho các eBGP peer khác. Trong bài lab này thì router Taos quảng bá route 192.168.100.0 đến Vail và Vail quảng bá tiếp tục đến Aspen. Do vậy routing table của Aspen có network 192.168.100.0
Aspen#sho ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
B 192.168.200.0/24 [20/0] via 192.168.1.221, 0124
192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks
B 192.168.1.0/24 [20/0] via 192.168.1.221, 01
B 192.168.1.224/30 [20/0] via 192.168.1.221, 01
B 192.168.1.216/30 [20/0] via 192.168.1.221, 01
C 192.168.1.220/30 is directly connected, Ethernet0/0
B 192.168.100.0/24 [20/0] via 192.168.1.221, 01
Aspen#sho ip bgp
BGP table version is 6, local router ID is 192.168.1.222
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
*> 192.168.1.0 192.168.1.221 0 100 200 ?
*> 192.168.1.216/30 192.168.1.221 0 100 200 ?
*> 192.168.1.224/30 192.168.1.221 0 100 200 ?
*> 192.168.100.0 192.168.1.221 0 100 200 ?
*> 192.168.200.0 192.168.1.221 0 100 200 ?
Tuy nhiên tại sao Vail lại không quảng bá network 192.168.1.220/30 đến Taos? Cần điều kiện gì để Vail quảng bá network này đến Taos ?
Taos#sho ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
D 192.168.200.0/24 [90/409600] via 192.168.1.217, 02:15:10, Ethernet0/0
192.168.1.0/24 is variably subnetted, 3 subnets, 2 masks
D 192.168.1.0/24 is a summary, 02:15:08, Null0
C 192.168.1.224/30 is directly connected, Serial1/0
C 192.168.1.216/30 is directly connected, Ethernet0/0
C 192.168.100.0/24 is directly connected, Loopback0
Taos#sho ip bgp
BGP table version is 6, local router ID is 192.168.100.1
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
*> 192.168.1.0 0.0.0.0 281600 32768 ?
*> 192.168.1.216/30 0.0.0.0 0 32768 ?
*> 192.168.1.224/30 0.0.0.0 0 32768 ?
*> 192.168.100.0 0.0.0.0 0 32768 ?
*> 192.168.200.0 192.168.1.217 409600 32768 ?
Cảm ơn.
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