之前有一个主题是：
专家面对面】-路由技术常见问题解答 的帖子中，有一个答复的结论是：多个asbr生成同一个external lsa，router id大的优选，别的条件相同情况下。RFC 2328: “If two routers, both reachable from one another, originate functionally equivalent AS-external-LSAs (i.e., same destination, cost and non-zero forwarding address), then the LSA originated by the router having the highest OSPF Router ID is used.”
这个做了一下实验，实验的操作系统是思科IOS： Version 12.4(10) 。 拓扑见附件。 R1和R2上重发布静态6.0.0.0/8 , R3上看到了数据库之后的FA地址，最后的路由表结果是进行了均衡负载，2条路径都加入了路由表。
R3#sh ip os da ex
OSPF Router with ID (3.3.3.3) (Process ID 1)
Type-5 AS External Link States
Routing Bit Set on this LSA
LS age: 1034
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 6.0.0.0 (External Network Number )
Advertising Router: 1.1.1.1
LS Seq Number: 80000006
Checksum: 0xCED
Length: 36
Network Mask: /8
Metric Type: 1 (Comparable directly to link state metric)
TOS: 0
Metric: 20
Forward Address: 16.1.1.6
External Route Tag: 0
Routing Bit Set on this LSA
LS age: 800
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 6.0.0.0 (External Network Number )
Advertising Router: 2.2.2.2
LS Seq Number: 80000003
Checksum: 0x628C
Length: 36
Network Mask: /8
Metric Type: 1 (Comparable directly to link state metric)
TOS: 0
Metric: 20
Forward Address: 26.1.1.6
External Route Tag: 0
R3#sh ip rou
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
34.0.0.0/24 is subnetted, 1 subnets
C 34.1.1.0 is directly connected, FastEthernet1/0
16.0.0.0/24 is subnetted, 1 subnets
O 16.1.1.0 [110/2] via 13.1.1.1, 00:12:40, FastEthernet0/0
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
O E1 6.0.0.0/8 [110/22] via 23.1.1.2, 00:12:40, FastEthernet2/0
[110/22] via 13.1.1.1, 00:12:40, FastEthernet0/0
23.0.0.0/24 is subnetted, 1 subnets
C 23.1.1.0 is directly connected, FastEthernet2/0
26.0.0.0/24 is subnetted, 1 subnets
O 26.1.1.0 [110/2] via 23.1.1.2, 00:12:44, FastEthernet2/0
13.0.0.0/24 is subnetted, 1 subnets
C 13.1.1.0 is directly connected, FastEthernet0/0
45.0.0.0/24 is subnetted, 1 subnets
O IA 45.1.1.0 [110/2] via 34.1.1.4, 00:12:47, FastEthernet1/0
