CCNA读书笔记（四）

Chapter4 Cisco’s Internetworking Operating System(IOS) and security Device Manager(SDM)

 

The IOS user interface

Cisco router IOS
1.       Carrying network protocols and functions
2.       connecting high-speed traffic between devices
3.       adding security to control access and stop unauthorized network use
4.       providing scalability for ease of network growth and redundancy
5.       supplying network reliability for connecting to network resources
 

Connecting to a Cisco router
1. console port   RJ45
2. auxiliary port    out-of-band
3. telnet           in-band
2800  Integrated Services Router(ISR)
 

Bring up a Router
POST power-on self-test
Flash memory –Cisco ISO
Flash memory is electronically erasable programmable read-only memory- an EEPRAM
NVRAM- startup-config
 

Bring up a non-isr router(a 2600)
If there isn’t a configuration in NVRAM, the router will broadcast looking for a valid one on a TFTP host. If the broadcast fails, it will then go into what is called setup mode.
 

 

 

 

Command-line interface(CLI)

Entering the CLI from a non-isr router
Router>enable     user mode > privileged exec mode
Router#disable
Router>logout
 

Overview of router models
Router# configure terminal
Show history
Show terminal
Terminal history size XX(max 256)
 

Gathering basic routing information
Show vision
 

Router and switch administrative configurations
1.       hostname
config t
hostname todd
2.       banners
MOTD(message of the day)
Banner motd #       #
3.       setting password
3.1enable password
Enable secret todd
Enable password todd
3.2 auxiliary password
Line aux 0
Password aux
Login
            console password
line console 0
password console
login
 

exec-timeout 0 0
logging synchronous
 

            telnet password
line vty 0 1180
password telnet
login
没有密码的情况下，允许telnet
Line vty 0 4
No login
 

Setting up secure shell(SSH)
 

Hostname todd
Ip domain-name lammle.com
Crypto key generate rsa general-keys modulus 1024
Ip ssh time-out 60
Ip ssh authentication-retries 2
Line vty 0 1180
Transport input ssh telnet
 

Encrypting your password
Service password-en
 

Router interfaces
Int f0/1
Description
Ip address 172.168.10.2 255.255.255.0
No shutdown
 

Using pipe
Show run | begin interface
Show ip route | include 192.168.2.32
 

Serial interface commands
Int s0/0/0
Clock rate 1000000
Show controllers s0/0/0
 

Bandwidth(default t1 1.544Mbps)
Int s0/0/0
Bandwidth 1000
 

Viewing,saving,and erasing configurations
DRAM>>NVRAM
Copy running-config startup-config
Show startup-config
 

Deleting the configuration and reloading the router
Erase startup-config
Reload
 

Verifying your configuration
Ping / traceroute
 

Show cdp entry * protocol
CDP(Cisco Discovery Protocol)
Show int fa0/0
Show ip interface
Show ip int brief
Show protocols