【菜鸟IT大讲堂】配置CDP协议

实验目的

1. 了解思科发现协议CDP的运行原理
2. 掌握思科发现协议CDP的配置方法

实验拓扑

实验需求

1. 根据实验拓扑图，完成设备的基本配置；
2. 在R1上使用CDP查看SW1和R2的设备信息；
3. 注意：CDP默认已经运行，不需要打开。

实验步骤

步骤1：设备的基本配置

配置R1：

Router>enable

Router#configure terminal

Router(config)#hostname R1

R1(config)#no ip domain-lookup

R1(config)#line console 0

R1(config-line)#exec-timeout 0 0

R1(config-line)#logging synchronous

R1(config-line)#exit

R1(config)#interface ethernet0/0

R1(config-if)#ip address 192.168.1.254 255.255.255.0

R1(config-if)#no shutdown

R1(config-if)#exit

R1(config)#interface ethernet0/1

R1(config-if)#ip address 192.168.12.1 255.255.255.0

R1(config-if)#no shutdown

R1(config-if)#end

R1#

配置R2：

Router>enable

Router#configure terminal

Router(config)#hostname R2

R2(config)#no ip domain-lookup

R2(config)#line console 0

R2(config-line)#exec-timeout 0 0

R2(config-line)#logging synchronous

R2(config-line)#exit

R2(config)#interface ethernet0/0

R2(config-if)#ip address 192.168.12.2 255.255.255.0

R2(config-if)#no shutdown

R2(config-if)#end

R2#

配置SW1：

Switch>enable

Switch#configure terminal

Switch(config)#hostname SW1

SW1(config)#no ip domain-lookup

SW1(config)#line console 0

SW1(config-line)#exec-timeout 0 0

SW1(config-line)#logging synchronous

SW1(config-line)#exit

SW1(config)#interface vlan 1

SW1(config-if)#ip address 192.168.1.1 255.255.255.0

SW1(config-if)#no shutdown

SW1(config-if)#exit

SW1(config)#ip default-gateway 192.168.1.254

SW1(config)#end

SW1#

实验检查

步骤1：检查设备的接口状态

检查R1：

R1#show ip interface brief

Interface IP-Address OK? Method Status Protocol

Ethernet0/0 192.168.1.254 YES manual up up

Ethernet0/1 192.168.12.1 YES manual up up

Ethernet0/2 unassigned YES unset administratively down down

Ethernet0/3 unassigned YES unset administratively down down

R1使用到的接口已经配置好IP地址，并且是up up状态。

检查R2：

R2#show ip interface brief

Interface IP-Address OK? Method Status Protocol

Ethernet0/0 192.168.12.2 YES manual up up

Ethernet0/1 unassigned YES TFTP administratively down down

Ethernet0/2 unassigned YES unset administratively down down

Ethernet0/3 unassigned YES unset administratively down down

R2使用到的接口已经配置好IP地址，并且是up up状态。

检查SW1：

SW1#show ip interface brief

Interface IP-Address OK? Method Status Protocol

Ethernet0/0 unassigned YES unset up up

Ethernet0/1 unassigned YES unset up up

Ethernet0/2 unassigned YES unset up up

Ethernet0/3 unassigned YES unset up up

Vlan1 192.168.1.1 YES manual up up

SW1使用到的接口已经配置好IP地址，并且是up up状态。

步骤2：使用CDP查看物理相连的设备信息

检查R1上运行CDP的接口:

R1#show cdp interface

Ethernet0/0 is up, line protocol is up

Encapsulation ARPA

Sending CDP packets every 60 seconds //CDP报文每60秒发送一次

Holdtime is 180 seconds //CDP保持时间是180秒

Ethernet0/1 is up, line protocol is up

Encapsulation ARPA

Sending CDP packets every 60 seconds

Holdtime is 180 seconds

Ethernet0/2 is administratively down, line protocol is down

Encapsulation ARPA

Sending CDP packets every 60 seconds

Holdtime is 180 seconds

Ethernet0/3 is administratively down, line protocol is down

Encapsulation ARPA

Sending CDP packets every 60 seconds

Holdtime is 180 seconds

cdp enabled interfaces : 4

interfaces up : 2

interfaces down : 2

R1的E0/0和E0/1接口已经运行CDP。

检查R1上的CDP邻居:

R1#show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,

D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID Local Intrfce Holdtme Capability Platform Port ID

SW1 Eth 0/0 169 R S I Linux Uni Eth 0/0

R2 Eth 0/1 163 R B Linux Uni Eth 0/0

Total cdp entries displayed : 2

R1上能够看到SW1和R2两个CDP邻居。

检查R1上的CDP条目:

R1#show cdp entry *

---

Device ID: SW1 //R1的CDP邻居SW1

Entry address(es):

IP address: 192.168.1.1 //SW1的IP地址

Platform: Linux Unix, Capabilities: Router Switch IGMP

Interface: Ethernet0/0, Port ID (outgoing port): Ethernet0/0 //R1的E0/0连接到了SW1的E0/0

Holdtime : 132 sec

Version :

Cisco IOS Software, Linux Software (I86BI_LINUXL2-ADVENTERPRISEK9-M), Version 15.2(CML_NIGHTLY_20190423)FLO_DSGS7, EARLY DEPLOYMENT DEVELOPMENT BUILD, synced to V152_6_0_81_E

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2019 by Cisco Systems, Inc.

Compiled Tue 23-Apr-19 02:38 by mmen

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VTP Management Domain: ''

Native VLAN: 1

Duplex: full

Management address(es):

IP address: 192.168.1.1

---

Device ID: R2 //R1的CDP邻居R2

Entry address(es):

IP address: 192.168.12.2 //R2的IP地址

Platform: Linux Unix, Capabilities: Router Source-Route-Bridge

Interface: Ethernet0/1, Port ID (outgoing port): Ethernet0/0 //R1的E0/1连接到了R2的E0/0

Holdtime : 124 sec

Version :

Cisco IOS Software, Linux Software (I86BI_LINUX-ADVENTERPRISEK9-M), Version 15.7(3)M2, DEVELOPMENT TEST SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2018 by Cisco Systems, Inc.

Compiled Wed 28-Mar-18 11:18 by prod_rel_team

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Management address(es):

IP address: 192.168.12.2

R1有两个CDP邻居，分别是SW1和R2。