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There are some basic commands that every Cisco certification network administrator should know.
1. ↑ / ↓ button: Call up the next/next command. Tab: Completion command. ? Key: Calls up all commands in the current mode.
2. Logout this login: exit, logout, quit.
3, no: cancel a configuration such as "no ip add 192.168.1.2255.255.255.0", or the anti-sense of the command such as "no
Shutdown".
Switch (vlan)# no vlan 2 Delete the VLAN numbered 2< Prerequisites This VLAN does not contain any ports> Switch(config-if)# no switchport access vlan 2Router(config-router)# no router rip Cancel dynamic routing of RIP configuration information
4. Abbreviation enable →en configure terminal→ conf t show→sh interface→int fastethernet
0/1→f0/1ethernet0/1→e0/1serial2/0 →s2/0 address →addpassword→pass shutdown→shutconsole→ con hostname→hostdatabase →data encapsulation→enca
Chapter 1 Overview of Computer Network Structure
1.> enable# config terminal Router (config)# interface fastethernet0/1 Switch (config)#interface vlan 1 User mode→privileged mode privileged mode→global configuration mode (router) global configuration mode→interface mode (switch) global configuration mode →Interface mode
2, # disable privileged mode → user mode
3, (config) # end global or interface mode → privileged mode, equivalent to "ctrl + z"
4, exit returns from the current mode to the previous mode
5, (config) #interface vlan 1 Enter vlan 1 interface
6. (config-if)# ip address 192.168.1.2 255.255.255.0 Configure the IP address of the current interface (note that the switch can only configure the IP of vlan1, and the router can configure the IP of the physical port)
7, (config-if) # no shutdown open the current interface
8, (config) # hostname R1 configure the host name, for example, R1 (this command is also available in interface mode)
9, # show version shows the system IOS name and version information
10, # show running-config displays the current configuration information
11, # show startup-config shows the saved configuration information
12, # copy running-config startup-config save the currently configured information (both commands can be)
13, #write
14, # erase nvram delete the saved configuration information (3 commands are available)
15, # delete nvram: startup-config
16, # erase startup-config
17. (config)# line console 0 (config-line)# exec-timeout 0 0 Modify the session timeout period to avoid returning to the initial interface (you need to press the Enter key to enter the user interface).
18, (config) # line con 0(config-line)# logging synchronous Starts the synchronization display, avoiding some information displayed by the console interrupting the configuration process when configuring the switch.
19, (config) # no ip domain-lookup disable DNS lookup
Chapter III Building an Office Network Environment
20, # show mac-address-t able [dynamic] display switch mac address table
21, (config-if)# duplex full (config-if)# duplex half(config-if)# duplex auto Configure the working mode of the current interface of the switch. Full full duplex half-duplex auto adaptive
22, (config-if) #speed 100 (config-if)#speed auto configure the communication rate of the current interface of the switch, in MHz
23, # show int f0/1 shows the duplex mode and communication speed of an interface
24, # ping 192.168.1.1–l 1000– t Test cable communication quality (this command can also be used in user mode) Chapter 4 Maintaining the office network environment
25, arp -a display ARP cache table
26, arp– d arp – d 192.168.1.2 delete arp cache table delete specific arp entries
27, arp–s 192.168.1.2 00-83-56-C0-00-01 static binding arp address
28, # show arp shows the ARP cache table of the router or switch
29, Switch # show mac-address-table display switch arp cache table (user mode can also use this command)
30, Switch# clear arp-cache clear switch or router arp table
31, (config-if) # arp 1.1.1.1 0011.1111.1111 arpa f0/22 bind the host's IP and MAC address on the gateway router, such as: Binding IP: 1.1.1.1 MAC: 1111.1111 to f0/22 port
Chapter VII Static Routes
32. Router(config)# ip route 192.168.1.0 255.255.255.0 192.168.10.2 50 Configure (floating) static route. Assume that the destination network address is 192.168.1.0, the subnet mask is 255.255.255.0, the local interface is 192.168.10.2, and the management distance is 50.
33. Router(config)# ip route 192.168.1.0 255.255.255.0 192.168.11.2 50 Configure the floating static route of the backup link.
34. Router(config)# ip route 0.0.0.0 0.0.0.0 192.168.11.1 50Configure the default route. Assume that the interface address of the next hop router is 192.168.11.1, and the management distance is 50.
35, Router# show ip route shows the routing table of the router
36. Router(config)# int s0/1 Router(config-if)# shut off the s0/1 interface of the router
37, (config) # access-list 1 permit 192.168.1.0 0.0.0.255 defines the access control list. Suppose the control list number is 1, and the address allowed by permit is 192.168.1.0 to 192.168.1.255.
38. Router(config)# ip nat inside source list 1 int f0/1 overload implements multiplexing of external interface addresses and dynamic conversion of IP addresses. Indicates a packet entering from the inside interface and meeting the access-list 1 requirement. Its source address will be PAT-converted; interface multiplexing on the f0/1 interface; overload overload.
39. Router(config)#intf0/0Router(config-if)#ipnatinsideRouter(config)#intf0/1
Router(config-if)# ip nat outside Enable PAT port multiplexing on the current interface of the router
Chapter VIII Management Network Equipment
40, (config) # line con 0(config-line)#password china123(config-line)#login configuration console
Port password. Assumed to be china123
41, (config) # enable password china123 configure the clear text password to enter the privileged mode
42, (config) # enable secret china456 configuration to enter the privileged mode encryption password
43, (config)# service password-encryption encrypts plaintext passwords
44, (config) # line vty 0 4(config-line)# password china123(config-line)# login Configure the switch VTY password. 04 indicates the number of interface numbers allowed to enter, assuming the password is china123
45, # telnet 192.168.1.2 remote login switch or router. This command is also available in user mode.
46, (config) # ip default-gateway 192.168.1.1 configuration default gateway
47, # copy tftp flash # copy flash tftp upgrade router IOS. Copy the router from the remote tftp server
IOS copies the router's IOS to a remote tftp server for backup
48, # copy ftp flash # copy flash ftp upgrade router IOS. Copy the router's IOS from a remote ftp server
Copy the router's IOS to the remote ftp server and back up the router password recovery (Press the Ctrl+Pause Break key to enter the ROM Monitor within 60s after power-off)
49, rommon1>confreg0x2142rommon2>reset Router#copystartup-config running-config#conft(config)#linecon0 (config-line)#nopassword(config-line)#exit(config)#config-register0x2102
(config)# exit # copy running-config startup-configModifies the configuration register value to 2142. Restart, enter setup mode. Save the startup-config configuration to running-config. Set the console port password to blank. Change the value of the configuration register back to 0x2102. Save the configuration switch password recovery (press and hold the MODE key → plug in the power → release the MODE button when Switch: appears)
50, flash_initrenameflash: config.textflash: config.oldboot#renameflash: config.old flash: config.text# copy flash: config.textsystem:running-config# conf t(config)#line con 0
(config-line)#nopassword(config-line)#end# copy running-configstartup-config Initialize FLASH Rename the configuration file in FLASH so that it will not load the password restart (or reset) → press Ctrl+C to enter directly system. Change the name of the configuration file back to manually load the configuration file and set the console port password to be empty. Save the configuration.
Chapter IX Benet Network Formation Project
51. Router (cofig)# ip dhcp pool global Configure the DHCP service. Define the address pool, assuming that poolname is global.
52. Router(dhcp-config)# network 192.168.1.0 255.255.255.0 dynamically allocates IP address segments
53, Router (dhcp-config) # default-router 192.168.1.254 set the gateway address
54. Router(dhcp-config)# dns-server 192.168.1.253 Configure the DNS address for the client.
55, Router (dhcp-config) # lease 3 set the address lease, assuming 3 days
56, Router (dhcp-config) # ip dhcp excluded-addres
