1：用自己的语言描述OSPF接口的类型及LSA新旧的比较

2：LAB：NBMA环境，使用OSPF协议使SPOKE端可以正常通信，不能修改接口的OSPF网络类型

作业一：用自己的语言描述OSPF接口的类型及LSA新旧的比较。

OSPF接口的类型有：broadcast，NBMA，point-to-point，point-to-muitipoint四种类型

可以通过：ip ospf network xx 命令修改类型参数。

Broadcast：hello-time为10s，dead时间为40s wait时间为40s， 组播发送

NBMA：hello-time为30s，dead时间为120s wait时间为120s， 单播发送

point-to-point：hello-time为10s，dead时间为40s wait时间为40s，组播发送

point-to-muitipoint：hello-time为30s，dead时间为120s wait时间为120s，组播发送。

LSA：默认为1800s更新一次，序列号增加1(默认序列号从0x80000001开始到0x7FFFFFFFF)，如果在3600s内没有收到更新信息，就老化LSA。

1:先比较LSA的序列号，值越大则越优先。

2：序列号一致时，则会比较checksum值，如果这个值越大则优先。

3：当序列号和checksum值都相同，则比较AGE时间是不是会等于3600s，如果相等，则表示为最新的。

4:如果AGE时间不等于3600s，会计算两者之间的差，如果差值大于15分钟，则越小月优先，如果小于15分钟，则视为同一条路由。

LAB：NBMA环境，使用OSPF协议使SPOKE端可以正常通信，不能修改接口的OSPF网络类型

使用拓扑图：

以下是R1,R2,R3设备的配置信息：

R1的配置信息：

R1(config-if)#do show run int s1/0 //验证接口s1/0的配置信息

Building configuration...

Current configuration : 202 bytes

!

interface Serial1/0

ip address 123.1.1.1 255.255.255.0 //接口s1/0的IP地址信息

encapsulation frame-relay //接口s1/0封装FR

serial restart-delay 0

frame-relay map ip 123.1.1.3 103 broadcast //FR map 配置

frame-relay map ip 123.1.1.2 102 broadcast //FR map 配置

end

R1(config-if)#do show fram map 验证FR map

Serial1/0 (up): ip 123.1.1.2 dlci 102(0x66,0x1860), static,

broadcast,

CISCO, status defined, active

Serial1/0 (up): ip 123.1.1.3 dlci 103(0x67,0x1870), static,

broadcast,

CISCO, status defined, active

R1(config-if)#do ping 123.1.1.2 //测试123.1.1.2的地址

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 123.1.1.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/8/12 ms

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

R2的配置信息：

R2(config-if)#do show run int s1/0 //验证接口s1/0的配置信息

Building configuration...

Current configuration : 158 bytes

!

interface Serial1/0

ip address 123.1.1.2 255.255.255.0 //接口s1/0的IP地址信息

encapsulation frame-relay //接口s1/0封装FR

serial restart-delay 0

frame-relay map ip 123.1.1.1 201 broadcast //FR map 配置

end

R2(config-if)#do show fram map

Serial1/0 (up): ip 123.1.1.3 dlci 201(0xC9,0x3090), static,

broadcast,

CISCO, status defined, active //在没有这一条的时候R2测试不通R3

Serial1/0 (up): ip 123.1.1.1 dlci 201(0xC9,0x3090), static,

broadcast,

CISCO, status defined, active

R2(config-if)#do ping 123.1.1.1 //测试123.1.1.1的地址

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 123.1.1.1, timeout is 2 seconds:

..!!!

Success rate is 60 percent (3/5), round-trip min/avg/max = 16/29/48 ms

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

R3的配置信息：

R3(config-if)#do show run int s1/0 //验证接口s1/0的配置信息

Building configuration...

Current configuration : 158 bytes

!

interface Serial1/0

ip address 123.1.1.3 255.255.255.0 //接口s1/0的IP地址信息

encapsulation frame-relay //接口s1/0封装FR

serial restart-delay 0

frame-relay map ip 123.1.1.1 301 broadcast //FR map 配置

end

R3(config-if)#do show fram map

Serial1/0 (up): ip 123.1.1.2 dlci 301(0x12D,0x48D0), static,

broadcast,

CISCO, status defined, active //在没有这一条的时候R3测试不通R2

Serial1/0 (up): ip 123.1.1.1 dlci 301(0x12D,0x48D0), static,

broadcast,

CISCO, status defined, active

R3(config-if)#do ping 123.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 123.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 12/24/40 ms

R3(config-if)#do ping 123.1.1.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 123.1.1.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 20/34/44 ms

R3可以ping通R1但是无法ping通R2因为没有到达R2和dlci号的对应关系不能进行通信。

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

为R1,R2,R3运行ospf并手工指定邻居：

R1的OSPF配置信息：

R1(config-router)#do show run | se ospf

ip ospf 110 area 0 //开启运行ospf动态路由协议区域0

router ospf 110 //运行ospf

log-adjacency-changes

network 1.1.1.0 0.0.0.255 area 0 //宣告网段

neighbor 123.1.1.2 //手工指定邻居

neighbor 123.1.1.3 //手工指定邻居

R1(config-router)#do show ip ospf int b

Interface PID Area IP Address/Mask Cost State Nbrs F/C

Lo0 110 0 1.1.1.1/24 1 LOOP 0/0

Se1/0 110 0 123.1.1.1/24 64 DR 2/2

R1(config-router)#do show ip route //验证路由信息

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

1.0.0.0/24 is subnetted, 1 subnets

C 1.1.1.0 is directly connected, Loopback0

2.0.0.0/32 is subnetted, 1 subnets

O 2.2.2.2 [110/65] via 123.1.1.2, 00:17:04, Serial1/0

3.0.0.0/32 is subnetted, 1 subnets

O 3.3.3.3 [110/65] via 123.1.1.3, 00:19:18, Serial1/0

123.0.0.0/24 is subnetted, 1 subnets

C 123.1.1.0 is directly connected, Serial1/0

R2的OSPF配置信息：

R2(config-router)#do show run | se ospf

ip ospf priority 0 //ospf 优先级改为0

ip ospf 110 area 0 //开启运行ospf动态路由协议区域0

router ospf 110 //运行ospf

log-adjacency-changes

network 2.2.2.0 0.0.0.255 area 0 //宣告网段

R2(config-router)#do show ip ospf int b

Interface PID Area IP Address/Mask Cost State Nbrs F/C

Lo0 110 0 2.2.2.2/24 1 LOOP 0/0

Se1/0 110 0 123.1.1.2/24 64 DROTH 1/1

R2(config-if)#do show ip route //验证路由信息

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

1.0.0.0/32 is subnetted, 1 subnets

O 1.1.1.1 [110/65] via 123.1.1.1, 00:16:35, Serial1/0

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 [110/65] via 123.1.1.3, 00:16:35, Serial1/0

123.0.0.0/24 is subnetted, 1 subnets

C 123.1.1.0 is directly connected, Serial1/0

R3的OSPF配置信息：

R3#show run | se ospf

ip ospf priority 0 //ospf 优先级改为0

ip ospf 110 area 0 //开启运行ospf动态路由协议区域0

router ospf 110 //运行ospf

log-adjacency-changes

network 3.3.3.0 0.0.0.255 area 0 //宣告网段

R3#show ip ospf int b

Interface PID Area IP Address/Mask Cost State Nbrs F/C

Lo0 110 0 3.3.3.3/24 1 LOOP 0/0

Se1/0 110 0 123.1.1.3/24 64 DROTH 1/1

R3(config-if)#do show ip route //验证路由信息

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

1.0.0.0/32 is subnetted, 1 subnets

O 1.1.1.1 [110/65] via 123.1.1.1, 00:28:38, Serial1/0

2.0.0.0/32 is subnetted, 1 subnets

O 2.2.2.2 [110/65] via 123.1.1.2, 00:15:58, Serial1/0

3.0.0.0/24 is subnetted, 1 subnets

C 3.3.3.0 is directly connected, Loopback0

123.0.0.0/24 is subnetted, 1 subnets

C 123.1.1.0 is directly connected, Serial1/0

测试结果：R3测试R1和R2

R3(config-if)#do ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/18/24 ms

R3(config-if)#do ping 2.2.2.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 20/28/40 ms