OSPF的多区域配置、优化方法，以及各类LSA（二）
查看R2的路由表如下：
Gateway of last resort is not set
O E1 192.168.89.0/24 [110/212] via 192.168.12.1, 00:01:03, Serial0/0
O IA 192.168.46.0/24 [110/65] via 192.168.1.4, 00:29:57, FastEthernet1/0
C 192.168.12.0/24 is directly connected, Serial0/0
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/65] via 192.168.12.1, 00:29:57, Serial0/0
O E1 192.168.47.0/24 [110/21] via 192.168.1.4, 00:01:03, FastEthernet1/0
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/2] via 192.168.1.3, 00:29:57, FastEthernet1/0
O IA 192.168.15.0/24 [110/128] via 192.168.12.1, 00:29:57, Serial0/0
O E1 192.168.8.0/24 [110/212] via 192.168.12.1, 00:01:03, Serial0/0
4.0.0.0/32 is subnetted, 1 subnets
O 4.4.4.4 [110/2] via 192.168.1.4, 00:29:58, FastEthernet1/0
O IA 192.168.58.0/24 [110/192] via 192.168.12.1, 00:29:58, Serial0/0
5.0.0.0/32 is subnetted, 1 subnets
O IA 5.5.5.5 [110/129] via 192.168.12.1, 00:29:58, Serial0/0
6.0.0.0/32 is subnetted, 1 subnets
O IA 6.6.6.6 [110/66] via 192.168.1.4, 00:29:58, FastEthernet1/0
172.5.0.0/24 is subnetted, 3 subnets
O IA 172.5.1.0 [110/129] via 192.168.12.1, 00:00:05, Serial0/0
O IA 172.5.3.0 [110/129] via 192.168.12.1, 00:00:05, Serial0/0
O IA 172.5.2.0 [110/129] via 192.168.12.1, 00:00:05, Serial0/0
172.16.0.0/24 is subnetted, 3 subnets
O E1 172.16.1.0 [110/212] via 192.168.12.1, 00:00:00, Serial0/0
O E1 172.16.2.0 [110/212] via 192.168.12.1, 00:00:00, Serial0/0
O E1 172.16.3.0 [110/212] via 192.168.12.1, 00:00:00, Serial0/0
7.0.0.0/24 is subnetted, 1 subnets
O E1 7.7.7.0 [110/21] via 192.168.1.4, 00:00:00, FastEthernet1/0
8.0.0.0/32 is subnetted, 1 subnets
O IA 8.8.8.8 [110/193] via 192.168.12.1, 00:29:58, Serial0/0
9.0.0.0/24 is subnetted, 1 subnets
O E1 9.9.9.0 [110/212] via 192.168.12.1, 00:00:00, Serial0/0
C 192.168.1.0/24 is directly connected, FastEthernet1/0
查看R5的路由表如下：
Gateway of last resort is not set
O E1 192.168.89.0/24 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
O IA 192.168.46.0/24 [110/193] via 192.168.15.1, 00:49:13, Serial0/1
O IA 192.168.12.0/24 [110/128] via 192.168.15.1, 00:49:13, Serial0/1
1.0.0.0/32 is subnetted, 1 subnets
O IA 1.1.1.1 [110/65] via 192.168.15.1, 00:49:13, Serial0/1
O E1 192.168.47.0/24 [110/149] via 192.168.15.1, 00:22:06, Serial0/1
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/129] via 192.168.15.1, 00:49:13, Serial0/1
3.0.0.0/32 is subnetted, 1 subnets
O IA 3.3.3.3 [110/130] via 192.168.15.1, 00:22:11, Serial0/1
C 192.168.15.0/24 is directly connected, Serial0/1
O E1 192.168.8.0/24 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/130] via 192.168.15.1, 00:49:14, Serial0/1
C 192.168.58.0/24 is directly connected, Serial0/0
5.0.0.0/24 is subnetted, 1 subnets
C 5.5.5.0 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
O IA 6.6.6.6 [110/194] via 192.168.15.1, 00:49:14, Serial0/1
172.5.0.0/24 is subnetted, 3 subnets
C 172.5.1.0 is directly connected, Loopback1
C 172.5.3.0 is directly connected, Loopback3
C 172.5.2.0 is directly connected, Loopback2
172.16.0.0/24 is subnetted, 3 subnets
O E1 172.16.1.0 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
O E1 172.16.2.0 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
O E1 172.16.3.0 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
7.0.0.0/24 is subnetted, 1 subnets
O E1 7.7.7.0 [110/149] via 192.168.15.1, 00:22:06, Serial0/1
8.0.0.0/32 is subnetted, 1 subnets
O 8.8.8.8 [110/65] via 192.168.58.8, 00:49:14, Serial0/0
9.0.0.0/24 is subnetted, 1 subnets
O E1 9.9.9.0 [110/84] via 192.168.58.8, 00:22:06, Serial0/0
O IA 192.168.1.0/24 [110/129] via 192.168.15.1, 00:49:14, Serial0/1
发现各路由器的LSDB和路由表都比较庞大，进行优化
1、在ABR路由器R1上做区域间路由汇总，配置如下：
router ospf 10
log-adjacency-changes
area 2 range 172.5.0.0 255.255.252.0
2、在ASBR路由器R8上做外部路由汇总，配置如下：
router ospf 10
log-adjacency-changes
summary-address 172.16.0.0 255.255.252.0
3、将OSPF area2更改为 total NSSA区域，配置如下：
在R5、R8的ospf进程下，配置如下命令：
area 2 nssa
在R1的ospf进程下，配置如下命令：
area 2 nssa no-summary //加入参数no-summary，将禁止外部（5类）LSA和汇总（3类和4类）LSA进入区域，而用一条默认路由代替。将自动生成一条3类的默认路由，并将其通告到NSSA中，no-summary参数仅需在ABR路由器上配置即可。
4、将OSPF area1更改为total stub区域，配置如下：
在R4的OSPF进程下配置：area 1 stub no-summary
在R6的OSPF进程下配置：area 1 stub
再次查看R5的路由表，如下：
Gateway of last resort is 192.168.15.1 to network 0.0.0.0
O N1 192.168.89.0/24 [110/85] via 192.168.58.8, 00:15:36, Serial0/0
C 192.168.15.0/24 is directly connected, Serial0/1
O N1 192.168.8.0/24 [110/85] via 192.168.58.8, 00:15:36, Serial0/0
C 192.168.58.0/24 is directly connected, Serial0/0
5.0.0.0/24 is subnetted, 1 subnets
C 5.5.5.0 is directly connected, Loopback0
172.5.0.0/24 is subnetted, 3 subnets
C 172.5.1.0 is directly connected, Loopback1
C 172.5.3.0 is directly connected, Loopback3
C 172.5.2.0 is directly connected, Loopback2
172.16.0.0/22 is subnetted, 1 subnets
O N1 172.16.0.0 [110/85] via 192.168.58.8, 00:15:36, Serial0/0
8.0.0.0/32 is subnetted, 1 subnets
O 8.8.8.8 [110/65] via 192.168.58.8, 00:15:37, Serial0/0
9.0.0.0/24 is subnetted, 1 subnets
O N1 9.9.9.0 [110/85] via 192.168.58.8, 00:15:37, Serial0/0
O*IA 0.0.0.0/0 [110/65] via 192.168.15.1, 00:15:37, Serial0/1 //由ABR路由器R1宣告进area2的默认路由
查看R5的LSDB表，如下：
R5#sh ip ospf da
OSPF Router with ID (5.5.5.5) (Process ID 10)
Router Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 842 0x80000007 0x000186 2
5.5.5.5 5.5.5.5 1100 0x8000000D 0x00678A 8
8.8.8.8 8.8.8.8 1101 0x80000008 0x00516F 3
Summary Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 1.1.1.1 1138 0x80000001 0x001B17
Type-7 AS External Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Tag
9.9.9.0 8.8.8.8 1108 0x80000001 0x002B90 0
172.16.0.0 8.8.8.8 1108 0x80000001 0x00DB41 0
192.168.8.0 8.8.8.8 1108 0x80000001 0x0066FE 0
192.168.89.0 8.8.8.8 1108 0x80000001 0x00E72C 0
仅剩1类、3类的默认路由和7类LSA
剩余部分请看（三）