先说点题外话,本来这两天是没时间来更新博客了的,但是事情出了点变化,使得我又有时间上网了,上网当然要到博客里面去逛逛了,没想到收到一封来自51cto的短信,说我的博客已经被评为推荐博客了,呵呵,真的很高兴能得到这样的荣誉,51cto让我感受到了学习的乐趣和写博客的动力(之前在csdn很没动力),更重要的是,能和这么多的网络技术爱好者共同学习,实在是一件很美妙的事情。感谢51cto。



       最近我的这几篇关于cisco基础实验的文章都有幸得到了推荐,从网友的回复看,大多数网友还是支持我的,虽然我的文章对一部分博友来说很初级,但他们都没有说,相反还得到了他们的多次指点,真的很谢谢他们。当然我相信,我不会永远做初级的实验的,我是按照进度来循序渐进的进行的,总会做到高级一点的实验的,呵呵,当然,今天的实验应该还算初级的,呵呵。下面看实验。



应用最为广泛的一种虚接口(即是接口不会依赖物理接口,接口的状态永远是UP的),网管完成网络规划之后,为了方便管理,会为每一台路由器创建一个loopback 接口,并在该接口上单独指定一个IP 地址作为管理地址,管理员会使用该地址对路由器远程登录(telnet)。因此学习它的配置还是有一定的意义的。



      

loopback接口在EBGP中使用的优点_Routing


    拓扑图如上所示,今天的实验通过show  的方式来展现,一来比较简短,二来比较易于察看,一目了然。


                      


                  1.1 在r1上show run:


 


r1#show run
Building configuration...


!
Version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r1
!
!
!
ip subnet-zero
!
!
!
!
!
!
!
!
!
!
interface Loopback
 ip address 10.1.1.1 255.255.255.0
 no ip directed broadcast
!
interface Serial0
 ip address 192.168.2.1 255.255.255.0
 no ip directed-broadcast
 clock rate 64000
!
interface Ethernet0
 ip address 192.168.1.2 255.255.255.0
 no ip directed-broadcast
!
!
router rip
 network 192.168.1.0
 network 192.168.2.0
 network 10.0.0.0     //我的loopback接口的IP地址为10.1.1.1
!
ip classless
no ip http server
!
!
!
line con 0
 transport input none
line aux 0
line vty 0 4                         /启用了vty线路方可进行telnet
 login
 password cisco
!
no scheduler allocate
end


 


                     1.2在r1上show ip route



r1# show 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
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
       U - per-user static route


Gateway of last resort is not set


     192.168.1.0/24 is subnetted, 1 subnets
C       192.168.1.0 is directly connected, Ethernet0
     10.0.0.0/24 is subnetted, 1 subnets
C       10.1.1.0 is directly connected, Loopback
     192.168.2.0/24 is subnetted, 1 subnets
C       192.168.2.0 is directly connected, Serial0
     192.168.3.0/24 is subnetted, 1 subnets
R       192.168.3.0 [120/1] via 192.168.2.2, 00:01:25, Serial0         //这个英文比较简单,应该看得懂


 


1.3 在r1上show ip  pro


 


r1#show ip pro
Routing Protocol is "rip"
  Sending updates every 30 seconds, next due in 7 seconds
  Invalid after 180 seconds, hold down 180, flushed after 240     //从这句可以得知:该配置采用rip协议,路由器每隔30s发出更新信息,(next due in 7 seconds?),超过180s未收到路由更新则认为该路由无效,如果经过240s还没收到更新信息,这该路由信息将会从路由表中删除。
  Outgoing update filter list for all interfaces is
  Incoming update filter list for all interfaces is
  Redistributing:   rip
  Default version control: send version 1, receive any version
    Interface        Send  Recv   Key-chain
    Serial0            1    1 2
    Ethernet0          1    1 2
  Routing for Networks:
    192.168.1.0
    192.168.2.0
    10.0.0.0
  Routing Information Sources:
    192.168.2.2           120      00:00:09
  Distance: (default is 120)       //rip的管理距离默认为120,该值越小越好


 


21.在r2上show run:


 


r2#show run
Building configuration...


!
Version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r2
!
!
!
ip subnet-zero
!
!
!
!
!
!
!
!
!
!
interface Serial0
 ip address 192.168.2.2 255.255.255.0
 no ip directed-broadcast
!
interface Ethernet0
 ip address 192.168.3.1 255.255.255.0
 no ip directed-broadcast
!
!
router rip
 network 192.168.3.0
 network 192.168.2.0
!
ip classless
no ip http server
!
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
!
no scheduler allocate
end


2.2在r2上show ip route


 


r2#show 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
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
       U - per-user static route


Gateway of last resort is not set


     192.168.2.0/24 is subnetted, 1 subnets
C       192.168.2.0 is directly connected, Serial0
     192.168.3.0/24 is subnetted, 1 subnets
C       192.168.3.0 is directly connected, Ethernet0
     192.168.1.0/24 is subnetted, 1 subnets
R       192.168.1.0 [120/1] via 192.168.2.1, 00:08:16, Serial0
     10.0.0.0/24 is subnetted, 1 subnets
R       10.1.1.0 [120/1] via 192.168.2.1, 00:02:14, Serial0


 


2.3 在r2上show ip pro


 


r2#show ip pro
Routing Protocol is "rip"
  Sending updates every 30 seconds, next due in 4 seconds
  Invalid after 180 seconds, hold down 180, flushed after 240
  Outgoing update filter list for all interfaces is
  Incoming update filter list for all interfaces is
  Redistributing:   rip
  Default version control: send version 1, receive any version
    Interface        Send  Recv   Key-chain
    Serial0            1    1 2
    Ethernet0          1    1 2
  Routing for Networks:
    192.168.3.0
    192.168.2.0
  Routing Information Sources:
    192.168.2.1           120      00:00:03
  Distance: (default is 120)  //意思同r1中的意思


                             3.pc1的配置


ipconfig /ip 192.168.1.1 255.255.255.0


ipconfig /dg 192.168.1.2


                              4.pc2的配置

ipconfig /ip 192.168.3.2 255.255.255.0

ipconfig /dg 192.168.3.1

                              5.远程登录验证

 

loopback接口在EBGP中使用的优点_网络_02


 如图所示,在输入telnet 10.1.1.1 并回车之后,会要求输入密码,此处为cisco,输入之后便可以在pc1上对r1进行配置。

        以前做实验,做完之后就只想到让它们互相ping通就好了,但是自从经过博友的提醒之后,才发现原来做实验并不仅仅局限于此,实验做完之后还可以学到很多的东西,再次谢谢众博友。 

转载于:https://blog.51cto.com/victoryan/39231