[原创总结]STUB、绝对STUB、NSSA、绝对NSSA对待默认路由及3类汇总的异同

2006年10月30日 7343点热度 0人点赞 0条评论

STUB区域:
自动多产生一条0.0.0.0 0.0.0.0的默认路由,原来的的区域间3类LSA还在.
r3#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       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 20.0.0.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/129] via 20.0.0.2, 00:01:34, Serial1/0
     20.0.0.0/24 is subnetted, 1 subnets
C       20.0.0.0 is directly connected, Serial1/0
     10.0.0.0/24 is subnetted, 1 subnets
O IA    10.0.0.0 [110/128] via 20.0.0.2, 00:01:34, Serial1/0
C    192.168.0.0/24 is directly connected, Ethernet0/0
O*IA 0.0.0.0/0 [110/65] via 20.0.0.2, 00:01:34, Serial1/0
r3#sh ip ospf data
r3#sh ip ospf database

OSPF Router with ID (20.0.0.3) (Process ID 1)

Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
20.0.0.2        20.0.0.2        227         0x80000004 0x00A88C 2
20.0.0.3        20.0.0.3        227         0x80000004 0x00999A 2

Summary Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
0.0.0.0         20.0.0.2        236         0x80000001 0x00F037
1.1.1.1         20.0.0.2        236         0x80000002 0x00439F
10.0.0.0        20.0.0.2        236         0x80000002 0x00E4F8

=========================
绝对STUB区域,只有0.0.0.0 0.0.0.0 的默认路由

r3#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       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 20.0.0.2 to network 0.0.0.0

     20.0.0.0/24 is subnetted, 1 subnets
C       20.0.0.0 is directly connected, Serial1/0
C    192.168.0.0/24 is directly connected, Ethernet0/0
O*IA 0.0.0.0/0 [110/65] via 20.0.0.2, 00:00:23, Serial1/0

r3#sh ip ospf database

OSPF Router with ID (20.0.0.3) (Process ID 1)

Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
20.0.0.2        20.0.0.2        46          0x80000008 0x00A090 2
20.0.0.3        20.0.0.3        46          0x80000008 0x00919E 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum
0.0.0.0 20.0.0.2 57 0x80000001 0x00F037

总结:不管是STUB还是绝对STUB,ABR都会自动产生一条0.0.0.0的默认路由,STUB区域的LSA3还存在,绝对STUB区域没有了其他区域的LSA3,只有自动产生的默认路由的3类LSA.

===========================

NSSA区域,默认不会产生默认路由(使用default-information-originate可以产生一个7类的0.0.0.0的默认路由),3类的LSA还存在.
r3#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       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 20.0.0.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/129] via 20.0.0.2, 00:01:45, Serial1/0
     20.0.0.0/24 is subnetted, 1 subnets
C     &nb

sp; 20.0.0.0 is directly c
onnected, Serial1/0
     10.0.0.0/24 is subnetted, 1 subnets
O IA    10.0.0.0 [110/128] via 20.0.0.2, 00:01:45, Serial1/0
C    192.168.0.0/24 is directly connected, Ethernet0/0
O*N2 0.0.0.0/0 [110/1] via 20.0.0.2, 00:01:45, Serial1/0

From:http://www.mycisco.cn

r3#sh ip ospf database

OSPF Router with ID (20.0.0.3) (Process ID 1)

Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
20.0.0.2        20.0.0.2        381         0x8000000F 0x0020FF 2
20.0.0.3        20.0.0.3        381         0x8000000F 0x00110E 2

Summary Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
1.1.1.1         20.0.0.2        388         0x80000005 0x00C413
10.0.0.0        20.0.0.2        388         0x80000005 0x00666C

Type-7 AS External Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Tag
0.0.0.0         20.0.0.2        388         0x80000001 0x004540 0
192.168.0.0     20.0.0.3        888         0x80000001 0x00E11D 0

====================================

绝对NSSA区域,其他区域的3类LSA不再被传播进来,自动产生一条0.0.0.0的默认路由（3类LSA）
r3#sh ip ospf database

OSPF Router with ID (20.0.0.3) (Process ID 1)

Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
20.0.0.2        20.0.0.2        1156        0x8000000F 0x0020FF 2
20.0.0.3        20.0.0.3        1156        0x8000000F 0x00110E 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum
0.0.0.0 20.0.0.2 205 0x80000001 0x0078A7

Type-7 AS External Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Tag
192.168.0.0     20.0.0.3        1663        0x80000001 0x00E11D 0
r3#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       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 20.0.0.2 to network 0.0.0.0

总结：

STUB，NSSA都还存在其他区域的3类LSA。

绝对STUB，绝对NSSA都不再存在有其他区域的3类LSA。

STUB，绝对STUB，绝对NSSA 都会自动产生一条3类的0。0。0。0的默认路由

NSSA区域如果要有默认路由，需要在ABR上配置area X nssa default-information-originate，且产生的是7类的0。0。0。0默认路由。