关于import-route static 和default-route-advertise区别知识总结
作者：互联网
关于import-route static 和default-route-advertise区别知识总结
一、相关解释
import-route static 命令不能引入外部路由的默认路由，OSPF通过路由表更新学习到外部路由的默认路由，
如果外部路由的默认路由需要在OSPF普通区域中发布，需要执行default-route-advertise 命令。
在正常情况下，构建OSPF协议运行体系，在外围网络设备中，对外部路由的注入OSPF，有两种独立的方法：
静态路由的引入用 import-route static，而默认路由用 default-route-advertise 引入，执行的位置都是在OSPF里。
这里需要注意的是，当外网特别不稳定时，防止OSPF反复计算，可设置 default-route-advertise always，其实就是管您外网状况如何，我当您正常并一直运行。
*** 别纠结，他这样做应该是研发人员碰到的不得已的问题，只能区别对待这两种情况，相对于对静态路由，为默认路由 0.0.0.0 0.0.0.0单独设计了一条命令，有点奢侈。：）
在网上收集到网友这样的解释，我认为是说的通的：协议设计上的规定，用来防范意外环路的。防止引入静态路由时注入默认路由，产生环路
二、相关验证
1.ENSP模型
2.基本配置
工作站IP地址配置，路由器接口配置，交换机vlan配置，vlan的虚接口IP地址配置
R1配置
#
interface GigabitEthernet0/0/0
ip address 192.168.20.254 255.255.255.0
#
interface GigabitEthernet2/0/0
ip address 192.168.19.1 255.255.255.0
R9配置
#
interface GigabitEthernet0/0/0
ip address 192.168.19.9 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 192.168.95.9 255.255.255.0
ip route-static 0.0.0.0 0.0.0.0 192.168.19.1 //末端路由器的默认路由配置
交换机配置
vlan batch 10 95
#
interface Vlanif10
ip address 192.168.50.254 255.255.255.0
#
interface Vlanif95
ip address 192.168.95.10 255.255.255.0
3.OSPF配置
R1配置
#
ospf 1 router-id 20.1.1.0
area 0.0.0.20
network 192.168.12.0 0.0.0.255
network 192.168.13.0 0.0.0.255
network 192.168.19.0 0.0.0.255
network 192.168.20.0 0.0.0.255
R9配置
#
ospf 1 router-id 20.1.9.0
default-route-advertise //这一条命令就是针对R9的默认路由的，将默认路由注入OSPF，并通过LSA报文传给其他相关方
area 0.0.0.20
network 192.168.19.0 0.0.0.255
network 192.168.95.0 0.0.0.255
交换配置
#
ospf 1 router-id 20.1.10.0
area 0.0.0.20
network 192.168.95.0 0.0.0.255
network 192.168.50.0 0.0.0.255
4.连通测试
[R9]dis ospf lsdb
OSPF Process 1 with Router ID 20.1.9.0
Link State Database
Area: 0.0.0.20
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 20.1.9.0 20.1.9.0 1103 48 8000000D 1
Router 20.1.10.0 20.1.10.0 1060 48 80000005 1
Router 20.1.1.0 20.1.1.0 659 72 8000000E 1
Network 192.168.95.9 20.1.9.0 1103 32 80000002 0
Network 192.168.19.1 20.1.1.0 659 32 80000003 0
AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 0.0.0.0 20.1.9.0 1438 36 80000001 1
External 192.168.40.0 30.3.70.0 1541 36 80000002 1
[SW1]dis ospf lsdb
OSPF Process 1 with Router ID 20.1.10.0
Link State Database
Area: 0.0.0.20
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 20.1.9.0 20.1.9.0 1273 48 8000000D 1
Router 20.1.10.0 20.1.10.0 1227 48 80000005 1
Router 20.1.1.0 20.1.1.0 829 72 8000000E 1
Network 192.168.95.9 20.1.9.0 1273 32 80000002 0
Network 192.168.19.1 20.1.1.0 829 32 80000003 0
AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 0.0.0.0 20.1.9.0 1607 36 80000001 1
External 192.168.40.0 30.3.70.0 1710 36 80000002 1
PC>ipconfig
Link local IPv6 address...........: fe80::5689:98ff:fefe:445a
IPv6 address......................: :: / 128
IPv6 gateway......................: ::
IPv4 address......................: 192.168.20.1
Subnet mask.......................: 255.255.255.0
Gateway...........................: 192.168.20.254
Physical address..................: 54-89-98-FE-44-5A
DNS server........................:
PC>ping 192.168.50.1 //连通测试正常
Ping 192.168.50.1: 32 data bytes, Press Ctrl_C to break
Request timeout!
From 192.168.50.1: bytes=32 seq=2 ttl=125 time=63 ms
From 192.168.50.1: bytes=32 seq=3 ttl=125 time=31 ms
From 192.168.50.1: bytes=32 seq=4 ttl=125 time=62 ms
From 192.168.50.1: bytes=32 seq=5 ttl=125 time=47 ms
--- 192.168.50.1 ping statistics ---
5 packet(s) transmitted
4 packet(s) received
20.00% packet loss
round-trip min/avg/max = 0/50/63 ms
标签：20.1,default,0.0,route,192.168,static,OSPF,路由 来源： https://www.cnblogs.com/gucun-blog/p/16558105.html