配置stub 区域，和 total-stub 区域。
R1# sh run
interface Serial2/1
ip address 12.0.0.1 255.255.255.0
router ospf 100
network 12.0.0.0 0.0.0.255 area 12
R2# sh run
interface Serial2/1
ip address 12.0.0.2 255.255.255.0
interface Serial2/2
ip address 23.0.0.2 255.255.255.0
router ospf 100
network 12.0.0.0 0.0.0.255 area 12
network 23.0.0.0 0.0.0.255 area 0
R3# sh run
interface Serial2/1
ip address 23.0.0.3 255.255.255.0
interface Serial2/2
ip address 34.0.0.3 255.255.255.0
router ospf 100
network 23.0.0.0 0.0.0.255 area 0
network 34.0.0.0 0.0.0.255 area 34
R4# sh run
interface Serial2/1
ip address 34.0.0.4 255.255.255.0
router ospf 34
network 34.0.0.0 0.0.0.255 area 34
------------------------------------------------------------------------\
R1(config-router)#int lo0
R1(config-if)#ip add 1.1.1.1 255.255.255.0
R1(config-if)#router ospf 100
R1(config-router)#redistribute connected subnets 将直连重分布进ospf 进程中。
R4(config-router)#do sh ip ospf nei
Neighbor ID Pri State Dead Time Address Interface
34.0.0.3 1 FULL/ - 00:00:34 34.0.0.3 Serial2/1
邻居建立起来了。
R4(config-router)#do sh ip ospf data
OSPF Router with ID (34.0.0.4) (Process ID 34)
Router Link States (Area 34)
Link ID ADV Router Age Seq# Checksum Link count
34.0.0.3 34.0.0.3 49 0x8000000E 0x00518D 2
34.0.0.4 34.0.0.4 48 0x8000000E 0x00429B 2
Summary Net Link States (Area 34)
Link ID ADV Router Age Seq# Checksum
12.0.0.0 34.0.0.3 58 0x80000004 0x00A6E1
23.0.0.0 34.0.0.3 58 0x80000004 0x009429
Summary ASB Link States (Area 34)
Link ID ADV Router Age Seq# Checksum
12.0.0.1 34.0.0.3 58 0x80000001 0x0094F4
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
1.1.1.0 12.0.0.1 1683 0x80000001 0x00513F 0
查看R4数据库，有1，3 ，4，5 型LSA.
因为2型LSA.是由广播型网络的 DR,或BDR 产生，在本实验使用的是点到点链路，所以没有2型LSA.。
R4(config-router)#do sh ip rout
Gateway of last resort is not set
34.0.0.0/24 is subnetted, 1 subnets
C 34.0.0.0 is directly connected, Serial2/1
1.0.0.0/24 is subnetted, 1 subnets
O E2 1.1.1.0 [110/20] via 34.0.0.3, 00:06:16, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
O IA 23.0.0.0 [110/128] via 34.0.0.3, 00:16:27, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
O IA 12.0.0.0 [110/192] via 34.0.0.3, 00:16:27, Serial2/1
R3(config-router)#area 34 stub
R4(config-router)#area 34 stub
将区域34 的路由器全部配置为stub区域。
R3(config-router)#do sh ip rou
Gateway of last resort is not set
34.0.0.0/24 is subnetted, 1 subnets
C 34.0.0.0 is directly connected, Serial2/2
1.0.0.0/24 is subnetted, 1 subnets
O E2 1.1.1.0 [110/20] via 23.0.0.2, 00:07:58, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
O IA 12.0.0.0 [110/128] via 23.0.0.2, 00:07:58, Serial2/1
R3路由表和配置stub区域前一样没有变、
R4(config-router)#do sh ip ospf da
OSPF Router with ID (34.0.0.4) (Process ID 34)
Router Link States (Area 34)
Link ID ADV Router Age Seq# Checksum Link count
34.0.0.3 34.0.0.3 1017 0x8000000C 0x00736F 2
34.0.0.4 34.0.0.4 1017 0x8000000C 0x00647D 2
Summary Net Link States (Area 34)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 34.0.0.3 1037 0x80000001 0x006CAC
12.0.0.0 34.0.0.3 1037 0x80000003 0x00C6C4
23.0.0.0 34.0.0.3 1037 0x80000003 0x00B40C
查看R4数据库，现在只有1，3 型LSA.。并且多了一条3型的默认路由
R4(config-router)#do sh ip rou
Gateway of last resort is 34.0.0.3 to network 0.0.0.0
34.0.0.0/24 is subnetted, 1 subnets
C 34.0.0.0 is directly connected, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
O IA 23.0.0.0 [110/128] via 34.0.0.3, 00:00:21, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
O IA 12.0.0.0 [110/192] via 34.0.0.3, 00:00:21, Serial2/1
O*IA 0.0.0.0/0 [110/65] via 34.0.0.3, 00:00:21, Serial2/1
查看R4路由表。此时路由表中没有了重分布进来的外部路由。多了一条3型的默认路由。结论：stub（末节区域）区域的路由器，不接收 那些关于本自治系统外的路由信息。只有域间域内的路由，lsa 1，lsa 2，lsa 3，过滤lsa 4，lsa 5，ABR向本区域的路由器产生默认路由。
R3(config-router)#area 34 stub no-summary 将区域34配置为total-stub区域。只需在ABR 上做就可以了。
R4(config-router)#do sh ip ospf da
OSPF Router with ID (34.0.0.4) (Process ID 34)
Router Link States (Area 34)
Link ID ADV Router Age Seq# Checksum Link count
34.0.0.3 34.0.0.3 148 0x80000012 0x006775 2
34.0.0.4 34.0.0.4 189 0x80000010 0x005C81 2
Summary Net Link States (Area 34)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 34.0.0.3 149 0x80000002 0x006AAD
查看R4数据库，现在只有1，默认3 型LSA.。
R4(config-router)#do sh ip rout
Gateway of last resort is 34.0.0.3 to network 0.0.0.0
34.0.0.0/24 is subnetted, 1 subnets
C 34.0.0.0 is directly connected, Serial2/1
O*IA 0.0.0.0/0 [110/65] via 34.0.0.3, 00:04:33, Serial2/1
查看R4路由表。将34区域配置为total-stub区域后。路由表中只有直连路由和一条默认路由。
结论：total-stub（完全末节区域）区域不接收外部自治系统路由或来自本自治系统内其他区域的汇总路由，过滤了4，5型和其他3型，只有1，2型和默认3型LSA. | 
