αααααααααΎαααΉααα·αα·αααααΎααα·ααΈααΆα BGP α ααΎαααΉααα·ααα·ααΆαααΌαααα’αααΈααΌαα ααα»αααααΆααΆ αα·αα ααα»α’αααΈααΆαααΆααΆααααΌαααΆαααααΎααΆαα·ααΈααΆααααα½ααααα ααΆαααααααΆαα
αααΎαααΆααααΎαααααΆαααααα α§ααΆα ααα
ααΌα ααααααΎ BGP ααΊααΆα’αααΈ? BGP ααΊααΆαα·ααΈααΆαααΆαααααΌαααΆααααα αα·αααΆαα·ααΈααΆα EGP (External Gateway Protocol) αααα½ααααα αα·ααΈααΆααααααααΌαααΆαααααΎααΎααααΈαααααΎαααααΌααα ααΎα’ααΈαααΊαα·αα ααΌααααα‘ααααΎαααΈααααααααααααΆαααα½αααααΌαααΆαααΆαααααααΆαααααααα BGP ααΈαα
αα·α
αΆαααΆααΈαααααΆαααααΆα Router1 αα·α Router3α α
αΌαααααααα
ααΆαααααααααα½αααΆαααααααΎααΆααααααααΆααΆααααααα
router bgp 10
network 192.168.12.0
network 192.168.13.0
neighbor 192.168.13.3 remote-as 10
router bgp 10
network 192.168.13.0
network 192.168.24.0
neighbor 192.168.13.1 remote-as 10
Neighborhood αα αααα»ααααααααααααααααααα½αααΊ AS 10α αααααΆααααΈαααα αΌαααααααΆααα ααΎααααααα ααΌα ααΆ Router1 ααααααααααααααΆααΆααααααΎαααααΆαααααααα αα·αααΆαα½α Router3α ααααΆαααΆαααααΌααα ααααααααααΆαα’αααΈααΎαα‘αΎαααααΌαααΆαααα α ααΆ ααααα. αααΆαααΆ bgp ααααΌαααΆαααααααα ααΆαααααααααα ααΎ Router1 ααΆααΉαα αΆααααααΎαααααΆαα TCP port 179 - ααΆααΉαα αΌααα αααα»ααααΆα ααααΆααα αΎααα ααααααααΆααααΆααΆαααΎα session ααΆαα½α Router3 ααΆααΉαα αΌααα αααα»ααααΆα αααααααα.
αααααΆααααΈααααααααΌαααΆααααααΎαα‘αΎααααΆα Router1 αα·α Router3 ααΆαααΎαααααΌαααΆαααααΆααααααΌαα αα ααααααααΆααααααααΌαααΆαααααΎααα Router1 ααααΆαααΆααααααΉαααααΌαααΆαα α ααΎαβααααΎ. α αΎααα ααααααααΆααα½αααΆαααΆαααΎαααΈ Router3 ααΆααΉαα αΌααα αααα»αααααΆαααΆα ααΎα αααααΆαα. ααΌααααα‘ααααΎαααΆααααααΎαα±ααααΆααααα αααΆααα
ααΆαααααααααΌαααααααΆαα’αααΈαα·ααΈααΆα BGP αααα½αααΆααααΆαα ααααααααααααααΎα ααΆααααααΆαααααΆααααααΌαααΆαααΎαα
αα Router1 αα·α Router3 ααααΆααααααααααααΆαα’αααΈααΆαααααααααααα½ααααα
ααααΆαα
αα·ααα
ααα αααΆαααΆααααααααΆααααααααααΌαααΆαααααααΆααα
- ααααα ααααα½ααααα αΌααααα BGP αααααααααααααα»αααααΎα αααααα αα α»αααααααα BGP ααΊααΆααααααΈ 4 αααααααΌαααΆααα·αααααΆαα αααα»α RFC 4271 α ααααααα BGP ααΈαααΉαααααΆααΆαα αα αΆαααααααααααΌαααααΆ αα ααααααααΆαααΆααα·ααααΈααααΆ αααααΆααΉααα·αααΆααααα BGP ααα
- α’αα αααααααα»αα ααααα½ααααα αΌαααΆααααα AS ααααααααα BGP αααααααααΉαααααΌααααααααααΎααα AS α αΎαααΆαααααααααΆααΎαα½αααααΉαααααΎαααΆα iBGP α¬ eBGP αααα¬ααα
- αα»ααααααααΆα ααααα·αααΎ BGP αα·αααα½αααΆαααΆααααααΆααα»α α¬ααααΎαα αα α»ααααααααΆαααΆαα½αααΈααΆααΈααααΆαααααααααΆααααααααααααΆααααα αΆαααα ααΆααΉααααααΆαααΆααΆααΈααααΆαααα 'ααααΆαα' α αΎαααΆααΉαααααΎα±ααααΌα αααα BGP α ααΆαααααΆαααΎα αααααααΆααααααααααΌαααΆααααααααααΉα 180 αα·ααΆααΈαα ααΎααααααα Cisco IOS ααΆααααααΆααΆαααααΌαααααΎαααααΆαα 60 αα·ααΆααΈα αααααααααΆααααΈαααααΌααααααααααΎαααααααΆαααα αΆα ααΎαα·αααΌα ααααααααΉααα·αααΆααααα BGP ααα
- α§ααααααααααα’ααααααααΆα BGPα αααααΊααΆααααααααΆααααααααα BGP ααΌαααααΆααααααααΌαααΆαααααΎαααΎαααΌα OSPF αααα
- ααααΎ Router-ID αααααααΌαααΆαααααααα ααΆααααααααααααααααααααΎααΆααααααααΆ bgp router-id α
- ααααΎα’αΆααααααΆα IP ααααααααα»ααα ααΎα ααα»α αααααΆααααααα·ααα»αα
- ααααΎα’αΆααααααΆα IP ααααααααα»ααα ααΎα ααα»α αααααΆααααΌαααααα
- αααΆαααΆααααααααααα α α·αααα αα ααΈαααα’αααααΉαααΎααααααααΆαααααα α α·ααααα½αα ααα½αααααααααααα BGP α ααΆααααααααΌαααΆααααααα ααΌα αααααα»αααΆαααααΈα’αΆα ααααΌαααΆααααααααα BGP ααααα·αα αΆαααΆα ααααααΎαααααααααΈα α’αααΈαααα’αααα’αΆα ααααΆααα ααΈαααααΊα
- ααΆαααΆαααααααααΆαα MP-BGP (αα·ααΈααΆααα α» BGP) α
- ααΆαααΆαααααααααΆααααααΌαααααΎα±αααααααα
- ααΆαααΆαααααααααΆααααα 4-octet AS α
ααΎααααΈαααααΎααααααΆαα ααααααααααΆααααααααααΌααααααααα
- αααααααα αααααα αα α»ααααααααΊ 4 α
- ααα AS ααααΌαααααααΌααααα’αααΈαααα’αααααΆαααααααα ααΆαααααααα α’ααααα·αααΆα 192.168.13.3 ααΈα ααααΆαααΌα 10.
- ααααααααΆαααααααααααααΌααααα»αααΈα’ααααα·αααΆαα
ααααα·αααΎαααΆαααΆααααααααΆαα½ααα·ααααααααααααααααΆααααα αααααααααΉααααααΌα ααα ααααΈααΌαααααΉα ααΆααααα αΆαααΈααα α»αα αααααΆααααΈααΆαααααΎ αα·αααα½αααΆαααΎα ααααΆααααααα’ααααα·αααΆαααΉαα αΌααα αααα»αααααΆαααΆα ααΆααααααΎαα‘αΎα. αααααΆααααΈααα αααααααα’αΆα ααααΆααααααΌαααααααΆαα’αααΈααααΌα αα·αααααΎααΆαααααααΎ ααααΎα±ααααΆαααααα ααΆαα αααααΆααΆα Update αααααααΎααα Router1 αα ααΆαα Router3α
αα ααΈαααα’αααα’αΆα ααΎαααΎααααααΆααααααΆαααΆαααΆαααααα Router1 αα·ααα»ααααααα Path αααααΆαααααααααααααααααΆαα ααΉαααααααα ααΎαααΉααα·ααΆαα’αααΈαα»αααααααααααΌαα±ααααΆαααααααα’α·αα ααΆα Keepalive ααααααΌαααΆαααααΎαα αααα»ααααα TCP αααααα αα½αααΆααααΌαααΆααααααΌαααΆαααααΆαααΎααααααΆαα 60 αα·ααΆααΈα αααααΊααΆαααααα·ααΈααααααααααααΆ Keepalive α ααααα·αααΎααΆα Keepalive αα·αααααΌαααΆαααα½ααααα»αα’αα‘α»αααα Hold Timer ααΆααΉαααΆααααααΆααΆαααααααααΆααααααααΆαα½αα’ααααα·αααΆαα ααΆαααααΆαααΎα ααΆααααΎααΉα 180 αα·ααΆααΈα
αααααΆααΆαααααααααα
ααΆα αΆααααΈααΌα ααΆααΎαααΆαααααααααααΈαααααααααααααααααααΌαααααααΆααα ααααΆαα αα·ααα αα α₯α‘αΌααααααΌαααααΆααΆαααααααααααΈαααααα·ααααΆαααα·ααΈααΆα BGP α
ααΎααααΈααααααααααΆαααααΌααα ααΆααααΆααΆα BGP ααΌα αα αααα»ααα·ααΈααΆα IGP ααΆααααααααΆαααααΆαααααΌαααΆαααααΎ ααα»αααααααααα·ααααΆααααα·ααααα·ααΆαααΊαα»αααααΆα ααααα·αααΎαα αααα»α IGP αααααΆααααΈαααααΆααααααΌααα αααα»αααΆααααααααΆαααααΆα IGP αα·αα·αααααΎαααΆααΎα ααα»α αααααΆααααΆαα½αααΆαααααα·αααα·αααααααααΆαααααα α αΎααα½ααααα αΌααα½αααΆαα αααα»αααΆααΆαααααααΆ αααααΆααααααΆααααααααΆαααααΆααα αααα»α BGP ααΎααα ααΆααΆαααΆαααααΌαα αΎαααααΎα α αααΆααααΆαα ααααΌααααααααΌααα αααα»αααΆααααααααΆαααααΆαα ααααα·αααΎααααΌαααΆαααααΎα ααααΌαααΆαααααααΉααααα αΆααα αααα»αααΆααΆα BGP α
ααααΎαααααΌααα αααα»αααΆααΆαααΆαααααΌα IP αα αα α»ααααααααααααααααα αααααααΌααααααΉααααΆαααΆααααααααααΆααααααααΆαααααΆαα ααααα·αααΎααααΌα IP ααΆα ααΌαααΆαα NLRI αααααααΌααα αααα»αααΆααΆα BGP ααΌαααααΆαα
α₯α‘αΌααααααΌαααΎα BGP αα ααΆααααααΌαααααα αααααΆααα’αα α αΎαααΎαααΈαααααααααααΌαααααΌαααΆαααααΎαααΎααααα»α AS αα½αα αααααΆααααΈααααααα BGP ααα½αααΆαααααΌαααΈα’ααααα·αααΆαααααααΆ ααΆα αΆααααααΎαααααΎαααΎαααααΌαααα’αααα»αα αα ααΈαααα’αααααααΌααααααΈααααααα’ααααα·αααΆααααα’αΆα ααΆα - ααΆααααα»ααα·αααΆααααα α ααΎααααααααααααΆαααΆααααααααΆααΎα’ααααα·αααΆααααααΆαααααααα ααΆααααααααααΊααΆααααα»αα¬ααΆααααα ? ααααα·αααΎαα αααα»ααααα»αα
neighbor 192.168.13.3 remote-as 10
αααΆαααΆααααααααΈα ααααΆαααααα AS αααααααΌαααΆαααααααα ααΆαααααααααα ααΎαααααααααααααα½αα―ααα αααα»αααΆααααααααΆ bgp 10 αααααααααααα ααααΌααααααααΈ AS ααΆααααα»αααααΌαααΆαα αΆαααα»αααΆααΆααΆααααα»α α αΎαααααΌαααΈααΆααααα AS ααααΌαααΆαα αΆαααα»αααΆααΆααααΌαααΆααααα α α αΎααααααΆααααααΆ αααααα·ααααΆαααααααααΆααααΆαααα½α αα·αααααΎααΆαααΆαα αα·α αΆαααΆααΎαααααΆααααααα
αααααααααΈαα½ααααΆαα ααα»α αααααΆααααααα·ααα»ααααααΆαααααααα ααΆααααααααααΆαα½α ip: xxxx 255.255.255.0 - ααα x ααΆααααααααααα αα ααΎ Router9 ααΎαααΆαα ααα»α αααααΆααααααα·ααα»αααΆαα½αα’αΆααααααΆα - 9.9.9.9 255.255.255.0 α ααΎαααΉααααααΆαααΆααΆαααα BGP α αΎαααΎαααΈαααααααααΆααΈαααΆαααΆαα ααααΌααααααΉαααααΌαααΆααααααΌααα ααΆαα Router8 αα·α Router12α ααΈ Router8 ααααΌααααααΉααα Router6 ααα»αααααα Router5 ααΆααΉααα·ααααα·ααα αααα»αααΆααΆαααΆαααααΌαααα ααααααα ααΎ Router12 ααααΌααααααΉααααα αΆααα αααα»αααΆααΆα ααα»αααααα ααΎ Router11 ααΆααΉααα·ααα ααΈααααααα αααααααΆααΆααααααααΆαααΏααααα α αΌαααΎααα·α αΆαααΆααΆααΎαα·αααααα αα·ααααΆαααΆααααααα’αααΈααααααα Router9 αααααΌααα ααΆααα’ααααα·αααΆααααααΆαααΆαααα’αααΈααααΌααααα αααα ααααααααΆαααΆααααααααΉαααααΌαααΆαααααΎααΈ Router9 αα Router8 α
ααααααΆαααααΌαααΆααα»αααααααααααΌαα
αα»αααααααααααΌαα ααα ααααΆ α€ ααααααα
- ααααΈααααΆαααΆααΆαααααα·α αα - αααααααααΆααα’αααααααααΎαααΆα BGP ααααΌαααααα½αααααΆαααα»αααααααααΆαααααα ααααΌαααααΆαααααααΆααα αααα»αααΆαα’αΆαααααααΆααα’ααα
- αααααΆαα»αα·αααα·ααααΈ - αααααααααΆααα’αααααααααΎαααΆα BGP ααααΌαααααα½αααααΆαααα»αααααααααΆαααααα αα½αααα’αΆα ααΆαααααααΆααα αααα»αααΆαα’αΆααααα ααα»ααααααααααΆααααααα½ααααα·αααααΌαααΆαααΆαααΆαααα
- α’ααααααΆαααααα α α·ααα - α’αΆα αα·αααααΌαααΆαααα½αααααΆαααααααΆαα’αα»αααα BGP ααΆααα’ααα ααααα·αααΎααααααααα·αααααΆαααα»ααααααααα ααΆαααααΆααααΆαα’αΆαααααααΆααααααα½α α αΎααααααΌαααΆαα α’ααααα·αααΆα ααααααααΆαα»ααα»αααααααααααα·αααα½αααααΆααα
- αααααΎααα·ααααα - α’αΆα αα·αααααΌαααΆαααα½αααααΆαααααααΆαα’αα»αααα BGP ααΆααα’ααα ααααα·αααΎααααααααα·αααααΆαααα»ααααααα ααααα»ααααααααα·αααααΌαααΆαα’αΎααΎ α αΎααααα αααα ααααααααΌααα α’ααααα·αααΆαα
α§ααΆα ααααααα»ααααααα BGPα
- ααααΈααααΆαααΆααΆαααααα·α
αα
:
- ααααΌααααααααααααααα
- αααααΆαα-α α
- αααααβααΎα
- αααααΆαα»αα·αααα·ααααΈ:
- α αααΌαα α·ααααααα»ααααα»α
- α’αΆααΌαααα»α
- α’ααααααΆαααααα
α
α·ααα:
- α’ααααααααΌααααα»α
- αα αααα
- αααααΎααα·ααααα:
- α’αααααΎαα’αΎααα α»α αααα αα (MED)
- ααααααααΆααα’ααααααααΎα
- αααααΈα ααααα
αααα»αααααΈααα αααααΆαααααααα ααΎαααΉαα αΆααα’αΆααααααααΎ Origin, Next-hop, AS Pathα α αΆααααΆααααΈααααΌααααααΌααααΆα Router8 αα·α Router9 αααααΊαα αααα»ααα½α AS ααΆααααΌαααΆαα αΆαααα»αααΆααΆαααααααα»αα αΎαααΎαααΉαααα α·ααααα»αααΆααα αααααααααααΎαα
αα»ααααααααααααααΎα - αααα αΆαααΈαααααααααααΌααα αααα»αααΆαα’αΆαααααααααΌαααΆαααα½αα ααααααα»ααααααααααα’αΆα ααααΎααΆαα
- 0 - IGP: NLRI ααΆαααα½ααα αααα»αααααααααααααααααΎαα
- 1 - EGP: NLRI ααααΌαααΆαααααααααααΎ Exterior Gateway Protocol (EGP)α α’αααααΆααααααααα»α BGP αα·αααααΌαααΆαααααΎααα
- 2 - αα·ααααααα: NLRI ααααΌαααΆααααααΆαααααααααααααα
αααα»αααααΈααααααΎα ααΌα αααα’αΆα ααΎαααΎαααΈαααα ααααααααΆα ααΆααααΎααΉα 0α αα ααααααααααΌααααααααΌαααΆααααααΌααα Router12 αααααΌααααααΉαααΆααααααΌα 1 α
αααααΆαα, Next-hop α αα»ααααααα Next-hop
- αααααΊααΆα’αΆααααααΆα IP ααααααααααα eBGP αααααΆααααααααΌααα ααΆαααααααΆαααααα αα α
- αα»αααααααααααΆααααααΌααα αααααααα»αααααααααΌαααΆαααααΎαα AS ααααααααα
αααα»αααααΈ iBGP αααααΊαααα»α AS αα½α Next-hop ααΉαααααΌαααΆαα ααα’α»ααααα αΆααααα’ααααααααα α¬ααααΆααα’αααΈααααΌααααα αααα»αααααΈααααααΎαααΆααΉαααΆ 192.168.89.9 α ααα»αααααα ααααααααααΌααααααααΌαααΆααααααΌαααΈ Router8 αα Router6 ααα Router8 ααΉαααααΆααααααΌαααΆ α αΎααααα½αααΆαααααααααΆα Next-hop ααΉαααΆα 192.168.68.8 α αααααΆαααΎααα ααα αααΆααααΈαα
- ααααα·αααΎααααααααααααΌαααααααααΌααα ααΆααα’ααααα·αααΆαααΆααααα»α ααΆαα·αααααΆααααααΌααααΆαααΆαααααα Next-hop ααα
- ααααα·αααΎααααααααααααΌαααααΌααα ααΆααα’ααααα·αααΆαααΆααααα ααααααΆ ααΆααααΆααααααΌα Next-hop αα ip ααα ααα»α αααααΆααααααααααααααααααααΌαα
αααααΆαα±ααααΎααααααΈαααα αΆααααΌα - α ααα»α’αααΈααΆαααΆααΆααΉααα·αααΆαααααΌααα αααα»αααΆααΆαααΆαααααΌααα ααΎ Router5 αα·α Router11 α α αΌαααΎααα·αα·αααααΎαα±ααααΆααααα αααΆααα ααΌα αααα Router6 ααΆαααα½αααααααΆαα’αααΈααααΌα 9.9.9.0/24 α αΎαααΆαααααααααΆαα αααα»αααΆααΆαααΆαααααΌααααααααααα
Router6#show ip route bgp
Codes: L - local, 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, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
Gateway of last resort is not set
9.0.0.0/24 is subnetted, 1 subnets
B 9.9.9.0 [20/0] via 192.168.68.8, 00:38:25<source>
Π’Π΅ΠΏΠ΅ΡΡ Router6 ΠΏΠ΅ΡΠ΅Π΄Π°Π» ΠΌΠ°ΡΡΡΡΡ Router5 ΠΈ ΠΏΠ΅ΡΠ²ΠΎΠΌΡ ΠΏΡΠ°Π²ΠΈΠ»Ρ Next-hop Π½Π΅ ΠΈΠ·ΠΌΠ΅Π½ΠΈΠ». Π’ΠΎ Π΅ΡΡΡ, Router5 Π΄ΠΎΠ»ΠΆΠ΅Π½ Π΄ΠΎΠ±Π°Π²ΠΈΡΡ <b>9.9.9.0 [20/0] via 192.168.68.8</b> , Π½ΠΎ Ρ Π½Π΅Π³ΠΎ Π½Π΅Ρ ΠΌΠ°ΡΡΡΡΡΠ° Π΄ΠΎ 192.168.68.8 ΠΈ ΠΏΠΎΡΡΠΎΠΌΡ Π΄Π°Π½Π½ΡΠΉ ΠΌΠ°ΡΡΡΡΡ Π΄ΠΎΠ±Π°Π²Π»Π΅Π½ Π½Π΅ Π±ΡΠ΄Π΅Ρ, Ρ
ΠΎΡΡ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΡ ΠΎ Π΄Π°Π½Π½ΠΎΠΌ ΠΌΠ°ΡΡΡΡΡΠ΅ Π±ΡΠ΄Π΅Ρ Ρ
ΡΠ°Π½ΠΈΡΡΡΡ Π² ΡΠ°Π±Π»ΠΈΡΠ΅ BGP:
<source><b>Router5#show ip bgp
BGP table version is 1, local router ID is 5.5.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
* i 9.9.9.0/24 192.168.68.8 0 100 0 45 i</b>
ααααΆαααΆαααΌα ααααΆααΉαααΎαα‘αΎααααΆα Router11-Router12α ααΎααααΈαααααΆαααααΆαααΆαααα α’αααααααΌαααααααα ααΆαααααααα Router6 α¬ Router12 αα αααααααααΆααααααΌααα ααΆααα’ααααα·αααΆαααΆααααα»ααααααα½ααα ααΎααααΈαααα½αα’αΆααααααΆα IP αααααα½αααααΆ Next-hop α αααααααΌαααΆαααααΎαααααααΎααΆααααααααΆα
neighbor 192.168.56.5 next-hop-self
αααααΆααααΈααΆααααααααΆααα Router6 ααΉαααααΎααΆαααααΎαα αα α»ααααααααΆα ααα ip ααα ααα»α αααααΆαα Gi0/0 Router6 ααΉαααααΌαααΆααααααΆααααΆ Next-hop αααααΆααααααΌα - 192.168.56.6 αααααΆααααΈαααααααΌααααααΉαααααΌαααΆααααα αΌααααα»αααΆααΆαααΆαααααΌααα½α α αΎαα
ααααα ααΎαααΆααΎααααΌααααααα α‘αΎααα ααΎ Router7 αα·α Router10 αααα¬ααα ααΆααΉααα·αααΆααα αααα»αααΆααΆα routing table αα α αΎαααΎααααα ααααΆαα·αααΆαααα αΆααΊααΌα ααααΆαα ααΉαααΈαα½αααΆαα½αααΉα Next-hop parameter ααα»ααααααααα·αααΎααΎαααΎααααααααα show ip bgp command ααΎαααΉαααΎαααΆ ααααΌααα·αααααΌαααΆαααα½ααα ααΈααααα αααααΈααΆααΆα Next-hop αα»α αααααΆααααααΆααααΌααα·αααααΌαααΆααααααΌαααΌααααΈααα α αΎααααααΉαααΆαααΎααα ααα’αααα·ααΆαααα αααΆαααα½ααααα
ααααΌααααααα½αααΆαααΈα’ααααα·αααΆαααΆααααα»ααα·αααααΌαααΆαααααααααααΆααα ααΆααα’ααααα·αααΆαααΆααααα»αααααααααααα
α
αΆααααΆααααΈ Router5 ααΆαααα½αααααΌαααΈ Router6 ααΆααΉααα·αααααΌαααΆααααααΌααα
α’ααααα·αααΆαααΆααααα»αααααααααααααααΆααα ααΎααααΈα±ααααΆααααααααΎαα‘αΎα α’αααααααΌαααααααα»αααΆα
neighbor 192.168.57.7 route-reflector-client
Route-Reflector ααααΆααααααΌαα₯αα·ααΆαααααα BGP αα αααααααααΆααααααΌααα ααΆααα’ααααα·αααΆαααΆααααα»αα ααααα·αααΎα’ααααα·αααΆαααΆααααα»αααααΌαααΆααααααΆαα ααααΌα - αααα»ααααα αΆαα - α’αα·αα·αααααααΆααααααααΌαααΆααααα»αααΉαααααΌαααΆαααααααααααΆααααα’αα·αα·ααααΆαααααα
ααααΌααα·αααα α‘αΎααα ααΎ Router7? αα»αααααα α’αααΈ Next-hop αααααα αααααΆααααΈα§ααΆαααααΆααααα ααααΌααααα½ααααα Router7 ααα»ααααααΆαα·αααΎαα‘αΎαααα αααααΆαααΎααα ααα αααΆαααα½ααααα
α αααΆααααααααααΆααααααΎαααΆααααααΆααααααααΌαααΆααααα ααα»αααααα αααααΆααααααΌαααΆααααα»α αα»ααααααα Next-hop αα·αααααΌαααΆααααα½αααα
α αΎαααΎαααα½αααΆαααααΆαααΆααααααΆα αΆαααΆα αααΎααααΈαααααΎαααα·ααΆααΆααααααααΎ static routing α¬ IGP protocols ααΎααααΈααΌαααααΉαααα router α’αααΈααααΌαααΆααα’αααα αααα»α AS α α αΌαααΎαα α»ααααααααααΌααα·αα·αααααα ααΎ Router6 αα·α Router7 α αΎααααααΆααααΈαααααΎαααΉαααα½αααΆαααααΌααααα ααααΆααα αααα»αααΆααΆααααααααα αα αααα»α AS 678 ααΎαααΉαααααΎααΆαα»αααααΆααααα·α ααααα½α - ααΎαααΉαα α»ααααααααααΌααα·αα·αααααααααΆαα 192.168.112.0/24 αα ααΎ Router10 αα·α 192.168.110.0/24 αα ααΎ Router12 α αααααΆαα ααΎαααΉααααααΎαααααΆαααααααααααΆαααααΆα Router10 αα·α Router12α ααΎαααααΉαααααααα ααΆαααααααα Router12 ααΎααααΈααααΎααΆαααααααααΆααααααααΆαα Router10α
neighbor 192.168.110.10 next-hop-self
ααααααααΉαααΊααΆ Router10 ααΉαααα½αααΆαααααΌα 9.9.9.0/24 ααΆααΉαααααΌαααΆαααα½αααΈ Router7 αα·α Router12α αααααΎαααΆααΎ Router10 ααααΎαααΎαα’αααΈααααα
Router10#show ip bgp
BGP table version is 3, local router ID is 6.6.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*>i 9.9.9.0/24 192.168.112.12 0 100 0 45 i
192.168.107.7 0 123 45 i
ααΌα
αααααΎαα’αΆα
ααΎαααΎα ααααΌαααΈα αα·ααααα½ααα½α (>) ααΆααααααΆααααΌαααΆαααα 192.168.112.12 ααααΌαααΆαααααΎαααΎαα
αααααΎαααΈαααααααααααΎαααΆαααααΎαααΎαααααΌαααααΎαααΆαα
- ααα αΆαααααΌααα αααααα½αααΆαααααΌαααΊααααΌααα·αα·αααααΎαααΆαα’αΆα ααααΆααα Next-hop ααααααΆα αααα αΎαααΆααΌαα ααα»ααααα ααααααααΎαααα½αααΆαααααΌααα ααΎ Router5 ααααα·αααααα Next-hop-self ααααΌαααααα·αααααΌαααΆαααααΎαααΆααααααααααααα
- αααααΆαααααααΆαααΆααααααααααααα αααΆαααΆααααααααααα·ααααααΆ Path Attribute (PA) α αΎααα·αααααΌαααΆαααααΎαααα»αααΆα BGP ααα ααΆααααΌαααΆαααααααα
ααΆαααααααααααα»αααΌαααααΆααα
ααΎαααααααααΈαα½αα α αΎαααααΌαααΆαααααΎααΎααααΈαααα
αααΆαααααΎαααΎαααααΌααα
ααΎααααααααααα½αα―αααα»αααααα ααΌααααα‘ααααΎαα§ααΆα ααααα½αα ααΆαααΎα’αααα’αΆα
ααΎαααΆ Router10 ααΆαααααΎαααΎαααααΌααααααΆαα 9.9.9.0/24 ααΆαααα Router12 (192.168.112.12)α ααΎααααΈααααΆααααααΌααααΆαααΆαααααα Wiight α’αααα’αΆα
ααααΎ route-map ααΎααααΈαααααααααΌαααΆααααΆαα α¬ααααααααααααααα’ααααα·αααΆαααααααΆαααααααΎααΆααααααααΆα
neighbor 192.168.107.7 weight 200
α₯α‘αΌααααααααΌαααΆααα’ααααΈα’ααααα·αααΆααααααΉαααΆααααααααααα ααΌαααΎαααΈααααααααααααΎαααααααΌαααααΆααααααΌααααααΆααααΈααΆααααα ααααα
Router10#show bgp *Mar 2 11:58:13.956: %SYS-5-CONFIG_I: Configured from console by console BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 192.168.107.7 200 123 45 i * i 192.168.112.12 0 100 0 45 i
ααΌα αααα’αααα’αΆα ααΎα ααααΌαααααααΆαα Router7 α₯α‘αΌααααααααΌαααΆαααααΎαααΎα ααα»ααααααΆααΉααα·αααΆααααααααΆααααΎ Router ααααααααααα
- αα
αααα»αααΈααΆααααΈααΈ ααΎαααΆα Local Preferenceα αααΆαααΆαααααααααααΊααΆαααααααα·αα·α
αααααααααααααΆααα
αααΆαα αααααΆααααααΆααααααΆαααααααΆααΊααααα
α
α·αααα αααΆαααΆαααααααααααΆααα»ααααΆααααααα»α AS αα½αααα»ααααα α αΎααααααΆααααααααααΎαααααΌααααααΆααααα’ααααα·αααΆαααΆααααα»αααα»αααααα αααα αΎαααΆααΌαα ααα»αααααΆααααΌαααΆααααααΌααααα
αααα»αααΆαα’αΆααααααααααΆααααααααααΆααα’ααααα·αααΆαααΆααααα»αααα»αααααα ααΆαα·αααΆαααααααΆααα
αααα»αααΆαα’αΆααααααααααΆααα’ααααα·αααΆαααΆααααα
ααα ααΌα
αααα ααΆααααΌαααΆαα
αΆααααααΆααααΆααΆ αααααΆαα»αα·αααα·ααααααΈα αααααΆαααααα’αα»ααααααΆαα
ααΎ Router5α αα
ααΎ Router5 ααΎααα½αααααΆαααααΌαααΈααααααΆαα 9.9.9.0/24 - αα½αααααααΆαα Router6 αα·αααΈααΈαααΆαααα Router7 α
ααΎαααΎααα α
Router5#show bgp BGP table version is 2, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 i
ααα»ααααααΌα αααααΎαααΎαααααΌααα½αααΆαααα Router6 α ααΎααααΌαααααααΆαα Router7 αα α―ααΆ? αααα ααααΆ Router7 αα·αααΆαααΆαα? αααααΎαα
Router#show bgp BGP table version is 10, local router ID is 7.7.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 i 192.168.107.10 0 678 45 i
α ααααα α’αααΈααααααααΆαα αΆααααΌα ααΆααα’α α ααα»α’αααΈααΆαααΆααΆαα·ααααααΌααα ααΆαα Router 5? ααΏαααΊααΆ BGP ααΆαα αααΆαααα½α:
ααααααααααααΌαααααααΌαααΆααααααααααΆααααΎα
Router7 ααααΎααααΌαααααααΆαα Router5 ααΌα ααααααααΌαααααααΆαα Router10 ααΉααα·αααααΌαααΆααααααΌαααα ααααααα‘αααα α αααΌαα α·ααααααα»ααααα»αα αααααααα Local Preference αα ααΎ Router7 α αΎαααΎαααΈααααααα Router5 ααααα·ααααα αααααααα αΆαααα
route-map BGP permit 10 match ip address 10 set local-preference 250 access-list 10 permit any router bgp 123 neighbor 192.168.107.10 route-map BGP in</b>
ααΌα αααα ααΎαααΆααααααΎααααααΈααααΌααααααΆαααααΌαααΆααα’αα α αΎαααααΆαα Router7 α±ααααααΌααααΆαααΆααααααα αααΌαα α·αααααΌαααααΆααα 250 αα αααααΆαααα½α ααααΆαααΎαααΊ 100α αααααΎαα’αααΈαααααΆαααΎαα‘αΎααα ααΎ Router5α
Router5#show bgp BGP table version is 8, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.57.7 0 250 0 678 45 i
ααΌα αααααΎαα’αΆα ααΎαα₯α‘αΌαααα Router5 α αΌαα α·αααααααΌαααααααΆαα Router7 α ααΌαααΆαααΌα ααααΆαααααΉαααΆααα ααΎ Router6 αααααΈααΆααΆααΆαααα ααααα αααΎαααΆααααααΆααααΆαααααα»αααΆαααααΎαααΎαααααΌαααααααΆαα Router8 αααααα ααΎαααααααααααΆααΆαααααΆααααααΌααααΆαααΆααααααααααααααΌαα±ααααΆαααΆαα αΆααααααΎααααααΆααα‘αΎααα·αααΎααααΈα±ααααΆαααααΆααααααΌαααΆαααααα·αααααΆαα α’αΆα
αα ααΈααα . ααΎαααΆαααααααα ααααΌαα αααΌαα α·ααααααα»ααααα»αα α αΌααααααα αααΆαααΆαααααααααααΆααα - α
αΌαα
α·αααααααΌααααααΆααααΆαααΆαααααα Next-hop 0.0.0.0 αααααΊααΆααααΌαααΌαααααΆα α¬ααααΌαααα»αα ααααΌαααΆαααααααααΌαααΆαααααααααααααααααααααα·ααΌααααΆαααΆααααααααααααααααΎααΉαα’αα·ααααΆβ32678βαααααΆααααΈαααα
αΌαααΆααααααααΆαααααΆαα
Router#show bgp BGP table version is 2, local router ID is 9.9.9.9 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 0.0.0.0 0 32768 i
- ααααΌαααααΈαααα»αααΆααααα’ααα αααΆαααΆαααααα AS_Path ααααΈαααα»αααααΌαααΆαααααΎαααΎαα ααααΌα ASs αα·α
ααΆααα»α ααΆααΆααααααα’α αα·α
αΆαααΆααααΌααα
ααΆαα 9.9.9.0/24 αα
ααΎ Router10α
Router10#show bgp BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path * 9.9.9.0/24 192.168.107.7 0 123 45 i *>i 192.168.112.12 0 100 0 45 i
ααΌα αααα’αααα’αΆα ααΎα Router10 ααΆαααααΎαααΎαααααΌαααΆαααα 192.168.112.12 ααΈααααααααααΆααααααΌαααα αααΆαααΆαααααα AS_Path ααΆαααααΉααα 45 α αΎααααα»αααααΈαα½αααα 123 αα·α 45 α α αααΆααααΆαααα·α αΆααααΆαα
- αααΆαααΆαααααααααααΆααααΊαααααααΎαα IGP (ααααΌααααααα½αααΆααααααααΎ BGP) αααααΎαααΆα EGP (ααααΌααααααα½αααΆααααααααΎ BGP ααααΆαααα»α αααααααΎα αΎα) α αΎα EGP αααααΎαααΆα Incomplete? (ααα½αααΆαααααα·ααΈααΆααααααααααααααα½αα ααα½α α§ααΆα ααααααααΆαα ααα αΆαα‘αΎααα·α)α
- αααΆαααΆαααααααααααΆααααΊ MED α ααΎαααΆα Wiight αααααααΎαααΆααααααα»αααΌαααααΆααα
ααΎαααααααααα»αααααα ααΆα Local Preference αααααααΎαααΆααααααα»ααααααααααααααααα½αααα»αααααα ααΌα
αααα’αααα’αΆα
ααΆαααΆα MED ααΊααΆαααΆαααΆαααααααααααΉαααααΌαααΆααααααΌααααΆαααααααααααααααα ααα’βααΆαα
α’ααααα α’αααΈαααΆαααΆαααααααααα
αα·αααΆααα»ααααααααααααααΉαααααΌαααΆαααααΎ ααα»ααααααααα·αααΎααααΌαααΈαααΆααα»αααααααααΌα ααααΆ αααα αααΆααααΆααααααααααΌαααΆαααααΎα
- ααααΎαααΎαααααΌαααααααΆααα’ααααα·αααΆα IGP ααααα αα·ααααα»αα
- ααααΎαααΎαααααΌαα αΆαααααα»ααααααΆααααααΌα eBGP α
- ααααΎαααΎαααααΌαααααααΆααα’ααααα·αααΆααααααΆαααααααααΆααααααααα BGP ααΌα αααα»αα
- ααααΎαααΎαααααΌαααααααΆααα’ααααα·αααΆααααααΆαα’αΆααααααΆα IP ααΆααααα»αα
α₯α‘αΌααααααΌααααα‘ααααΎααααα αΆααααΆααααα αΌαααααΆ BGP α
αααααΎαααΆααΎααΆαα’αααΈααΎαα‘αΎαααααα·αααΎ Router6 ααΆαααααααααΌα 9.9.9.0/24 ααΆαααα Router9 α ααααα·αα ααα»α αααααΆαα Gi0/1 αα Router6 αααααΉααααααααΆααααΆαααα BGP ααΆαα½α Router8 ααααΌαααΆααααα αα α αΎαα’ααααα·αααΆαααΆαααΆαα αααααΆααααααΆααααΌααααααΆαααα½αααΈααΆαα·αααααΉαααααΌαα Router6 ααααΎααΆαααααΎαα αα α»ααααααααΆαααααΆαα αααααΆαααα αΆαααΈαααααΆα 9.9.9.0/24 αα αααα»αααΆαααααααΌαα αα αααααα Router5 ααα½αααΆαααΆααααααα ααΆααΉααααααΌαααΆαα ααΆαα Router7α ααα»αααααααααΆα Router7 ααΆαααααΌαααααααΆαα Router10 ααΆααΉαααααΎαααααααΆααααΆαα½αααΉαααΆα Update ααΆαα½αααΉαααααΌαααααΈαα½αα ααααα·αααΎαα·αα’αΆα ααααΎαααΆααα½ααααααααα’ααααα·αααΆααααααα’ααααΎααααΆαααΆαααα ααα»α αααααΆααααααα α’αααααΉαααααΌααααα αΆαα±αααααααα·ααΈαααααααααααααααα
αα αααααα
ααααα·αααΎα’αααα αΆα ααΎαααΆααα·ααΆαα’αααΈααΆααα·ααααααΆααΏααα’αααααααΌαααααΎ topology αααααααΆαααααΆαααααααα ααΆαα½αααΉαα ααα½αααα αααΎαααααααααααα αααα»α AS αααα’αΆα αααααΆαα±ααααΆααααα αΆαα ααΎααααΈαααααΆααααα αΆαααα’αααααααΌαααααΎαα αααααα αα½α AS ααααΌαααΆααααα αααα ααΆ AS ααααΆα αααΎα αααα’αα»ααααΆαα±αααα½αααΆααααΎαααΆαααααα·αα αΆαααΆα αααΆαααααΌαααΆααα topology αααααααΆαααααΆαααααααα
αααααΊααΆαααααααΆαααα
αααα
ααΆα§ααΆα ααα ααΆαα½αααΉα topology ααα ααΎαααΉαααααΌαααααΆαα Router ααΆααα’αααα αααα»α AS 2345 αα ααααΆαα αα·ααα αα ααα»αααααααααααΎ Confederation ααΎαα’αΆα αααααΎαααααΆαααααα adjacency ααΆααααααΆα routers αααααααΆαααααααααΆαααα ααααΆαα αα·ααα ααααα»αααααα α αΌααα·ααΆαα’αααΈααΏααααα±ααααΆαααα’α·αα ααααα·αααΎααΎαααΆα AS 2345 ααα»αααααα α‘αΆα ααα αααααΆαααα½αααΆαα ααααα½αααΈ Picard ααΉαααααΆααααΆαα ααααααα αα·αααααα ΠΈ αααΌα ααααα»αααααα½αααααΉααα·αααααΆαααααααααα’αααΈααΆααα α’ααααα·α . ααααΌααααα ααα αΆααααααααααααααα½αα―ααααααα α‘αΆα ααα , ααΉααα·αααααΌαααΆαααααα α’ααααα·α αα·α αααΌα αα-α’αΌβαα αα·αααααα.
α’αααααΉαααααΌαααααααα
ααΆαααααααα Route-Reflector α¬ααααΆαααααααααααΆαααααααααΆαααααΆαααααααα ααααααα
αα AS 2345 αα
ααΆ 4 α’αα» AS (2,3,4,5) αααααΆαααααααααααΈαα½αα ααΎααααα
ααααααααααα·ααααΆααααα·ααααα·ααΆααααααααααΆα α’αααΈααααααααΆαααααΌαααΆααα·αααααΆαααΆαααα’α₯αααα
αα
ααααα:
- CCIE Routing and Switching v5.0 ααααα»ααααααααα·ααααΆααααααααααΌαααΆα ααα 2 ααΆαααααα»αααααΎαααΈααααΆα Narbik Kocharians Terry Vinson α
- ααα ααααα
xgu.ru - ααα ααααα
ααααΆαααααααΆαα GNS3 .
ααααα: www.habr.com