Border Gateway Protocol
Notes
Bảng thuộc tính BGP (Thường dùng)
| Name | Type |
|---|---|
| Nexthop | Well-known mandatory |
| Local Preference | Well-known discretionary |
| AS Path | Well-known mandatory |
| Origin | Well-known mandatory |
| Community | Optional transitive |
Chuẩn bị
# R1
set interfaces ge-0/0/0 unit 0 family inet address 10.0.12.1/29
set interfaces ge-0/0/1 unit 0 family inet address 10.0.13.1/29
set interfaces lo0 unit 0 family inet address 1.1.1.1/32
set protocols ospf area 0.0.0.0 interface lo0.0
set protocols ospf area 0.0.0.0 interface ge-0/0/0.0
# R2
set interfaces ge-0/0/0 unit 0 family inet address 10.0.24.2/29
set interfaces ge-0/0/1 unit 0 family inet address 10.0.12.2/29
set interfaces lo0 unit 0 family inet address 2.2.2.2/32
set protocols ospf area 0.0.0.0 interface lo0.0
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
# ISP-A
set interfaces ge-0/0/0 unit 0 family inet address 10.0.13.3/29
set interfaces lo0 unit 0 family inet address 3.3.3.3/32
# ISP-B
set interfaces ge-0/0/1 unit 0 family inet address 10.0.24.4/29
set interfaces lo0 unit 0 family inet address 4.4.4.4/32
Cấu hình BGP
# R1
set routing-options autonomous-system 65503
set protocols bgp group int-65503 type internal
set protocols bgp group int-65503 local-address 1.1.1.1
set protocols bgp group int-65503 neighbor 2.2.2.2
set protocols bgp group ext-65501 type external
set protocols bgp group ext-65501 peer-as 65501
set protocols bgp group ext-65501 neighbor 10.0.13.3
# R2
set routing-options autonomous-system 65503
set protocols bgp group int-65503 type internal
set protocols bgp group int-65503 local-address 2.2.2.2
set protocols bgp group int-65503 neighbor 1.1.1.1
set protocols bgp group ext-65502 type external
set protocols bgp group ext-65502 peer-as 65502
set protocols bgp group ext-65502 neighbor 10.0.24.4
# ISP-A
set routing-options autonomous-system 65501
set protocols bgp group ext-65503 type external
set protocols bgp group ext-65503 peer-as 65503
set protocols bgp group ext-65503 neighbor 10.0.13.1
# ISP-B
set routing-options autonomous-system 65502
set protocols bgp group ext-65503 type external
set protocols bgp group ext-65503 peer-as 65503
set protocols bgp group ext-65503 neighbor 10.0.24.2
Cấu hình next-hop-self
# R1
set policy-options policy-statement next-hop-self-policy term alter-next-hop then next-hop self
set protocols bgp group int-65503 export next-hop-self-policy
Cấu hình quảng bá prefix
# R1
set policy-options policy-statement adv-prefix term match-prefix from route-filter 2.2.2.2/32 exact
set policy-options policy-statement adv-prefix term match-prefix then accept
set protocols bgp group ext-65501 export adv-prefix
# ISP-A
set policy-options policy-statement adv-prefix term match-prefix from route-filter 3.3.3.3/32 exact
set policy-options policy-statement adv-prefix term match-prefix then accept
set protocols bgp group ext-65503 export adv-prefix
Kiểm tra
- Kiểm tra bgp peer
root@R1> show bgp summary
Groups: 2 Peers: 2 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
1 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
2.2.2.2 65503 24 43 0 0 17:58 0/0/0/0 0/0/0/0
10.0.13.3 65501 33 46 0 0 19:04 1/1/1/0 0/0/0/0
root@R2> show bgp summary
Groups: 2 Peers: 2 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
1 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
1.1.1.1 65503 42 24 0 0 9:41 1/1/1/0 0/0/0/0
10.0.24.4 65502 49 26 0 0 10:17 0/0/0/0 0/0/0/0
root@ISP-A> show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
1 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
10.0.13.1 65503 46 34 0 0 14:01 1/1/1/0 0/0/0/0
root@ISP-B> show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
1 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
10.0.24.2 65503 26 50 0 0 21:06 1/1/1/0 0/0/0/0
- Kiểm tra route bgp
root@R2> show route protocol bgp
inet.0: 8 destinations, 8 routes (8 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
3.3.3.3/32 *[BGP/170] 00:06:54, localpref 100, from 1.1.1.1
AS path: 65501 I, validation-state: unverified
> to 10.0.12.1 via ge-0/0/1.0
root@ISP-A> show route protocol bgp
inet.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
2.2.2.2/32 *[BGP/170] 00:09:53, MED 1, localpref 100
AS path: 65503 I, validation-state: unverified
> to 10.0.13.1 via ge-0/0/0.0
- Kiểm tra ping
root@R2> ping rapid 3.3.3.3 source 2.2.2.2
PING 3.3.3.3 (3.3.3.3): 56 data bytes
!!!!!
--- 3.3.3.3 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.938/1.166/1.373/0.165 ms
root@ISP-A> ping rapid 2.2.2.2 source 3.3.3.3
PING 2.2.2.2 (2.2.2.2): 56 data bytes
!!!!!
--- 2.2.2.2 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.291/1.902/3.744/0.930 ms