2.2 实验1：模式切换、上下文帮助及查看有关信息
本实验进行路由器IOS软件的基本操作，包括在各种CLI模式之间切换，使用上下文帮助，查验IOS版本信息，以及查看路由器基本组件信息。
1.实验目的
通过本实验，读者可以把握以下技能:
在用户执行模式、特权执行模式和配置模式之间切换;
查看各种模式下命令的区别;
熟悉上下文关联帮助的使用;
查看IOS版本信息;
查看路由器各基本组件信息。
2.设备需求
本实验需要以下设备:
Cisco路由器1台，型号不限;
PC机1台，操作系统为Windows系列;
Console电缆1条及相应的接口转换器。
3.线缆连接及配置说明
如图2-1所示，PC机通过串口与路由器的console端口直接相连。
4.实验配置及监测结果
实验环境预备就绪后，开启PC机和路由器的电源，开始进行实验。
用PC机系统中的超级终端程序访问路由器，监测清单2.1记录了整个操作过程。
监测清单2-1实验1的操作与命令说明
Router (用户执行模式）
Routerenable (进入特权执行模式)
Routed (特权执行模式提示符)
Router#conf t (向全局配置模式切换)
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# (全局配置模式提示符)
Router(config)#interface ethernet 0 (进入interface配置模式)
Router(config-if)# ( interface配置模式提示符)
Router(config-if)#? (查看interface配置模式下的所有配置命令)
Interface configuration commands:
access-eXPRession Build a bridge boolean access expression
appletalk Appletalk interface subcommands
arp Set arp type (arpa, probe, snap) or timeout
backup Modify backup parameters
bandwidth Set bandwidth informational parameter
bridge-group Transparent bridging interface parameters
carrier-delay Specify delay for interface transitions
cdp CDP interface subcommands
cmns OSI CMNS
... (此处省略)
standby Hot standby interface subcommands
timeout Define timeout values for this interface
traffic-shape Enable Traffic Shaping on an Interface or Sub-Interface
transmit-interface Assign a transmit interface to a receive-only interface
tx-ring-limit Configure PA level transmit ring limit
Router(config-if)#ip add? (使用“？”查看以add开头的命令)
address
Router(config-if)#ip address? (使用“？”查看ip address后面的命令)
A.B.C.D IP address
Router(config-if)#ip address 192.168.1.1 ?
A.B.C.D IP subnet mask
Router(config-if)#ip address 192.168.1.1 255.255.255.0 ?
secondary Make this IP address a secondary address
Router(config-if)#ip address 192.168.1.1255.255.255.0
Router(config-if)#exit (退出interface配置模式，进入全局配置模式)
Router(config)#? (查看全局配置模式下的所有配置命令)
configure commands:
aaa Authentication, Authorization and Accounting.
access-list Add an access list entry
alias Create command alias
appletalk Appletalk global configuration commands
arap Appletalk Remote Access Protocol
arp Set a static ARP entry
async-bootp Modify system bootp parameters
... (此处省略)
tFTP-server Provide TFTP service for netload requests
time-range Define time range entries
usemame Establish User Name Authentication
virtual-profile Virtual Profile configuration
x25 X.25 Level 3
x29 X29 commands
Router(config)#exit (退出配置模式，进入特权执行模式)
Router#? (查看特权执行模式下所有的命令)
Exec commands:
access-enable Create a temporary Access-List entry
access-profile Apply user-profile to interface
access-template Create a temporary Access-List entry
archive manage archive files
bfe For manual emergency modes setting
cd Change current Directory
clear Reset functions
... (此处省略)
telnet Open a telnet connection
terminal Set terminal line parameters
test Test subsystems, memory, and interfaces
traceroute Trace route to destination
tunnel Open a tunnel connection
udptn Open an udptn connection
undebug Disable debugging functions (see also 'debug')
verify Verify a file
where List active connections
write Write running configuration to memory, network, or terminal
x28 Become an X.28 PAD
x3 Set X.3 parameters on PAD
Router#disable (退出特权执行模式，进入用户执行模式)
Router? (查看用户执行模式下的所有命令)
Exec commands:
access-enable Create a temporary Access-List entry
access-profile Apply user-profile to interface
... (此处省略)
udptn Open an udptn connection
where List active connections
x28 Become an X.28 PAD
x3 Set X.3 parameters on PAD
Routershow version (查看路由器的版本信息和组件信息)
Cisco Internetwork Operating System Software
IOS(tm)2500 Software(C2500-D-L),Version 12.1(8a),RELEASE SOFTWARE(fc1) IOS版本信息
Copyright (c) 1986-2001 by cisco Systems, Inc.
Compiled Wed 23-May-01 01:20 by yiyan
Image text-base: 0x0000144C, data-base: 0x00843EA8
ROM:System Bootstrap. Version 5.2(8a), RELEASE SOFTWARE ( ROM 版本信息)
BOOTFlash: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fcl)
Router uptime is 56 minutes (本路由器的开机时间)
System returned to ROM by power-on
System image file is "flash:c2500-d4.121-8a.mz" ( Flash中的IOS映像文件名)
cisco 2500 (68030) processor (revision L) with 14336K/2048K bytes of memory. (处理器信息)
Processor board ID 03215594, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
2Ethernet/IEEE 802.3 mterface(s) (路由器物理接口)
2Serial network interface(s) (路由器物理接口)
32K bytes of non-volatile configuration memory. ( NVRAM, 大小为32K )
8192K bytes of processor board System flash (Read/Write) (Flash, 8192K)
Configuration register is 0x2102 (配置寄存器值)
Routershow flash (查看Flash具体信息)
System flash directory:
File Length Name/status
1 4289602 c2500-d-1.121-8a.mz
[4289668 bytes used, 4098940 available, 8388608 total] ( Flash的已用空间、可用空间和总空间)
8192K bytes of processor board System flash (Read/Write) ( Flash的容量及状态)
Router
上面我们用比较长的篇幅记录了路由器的模式切换、帮助使用、组件查看等操作，并对所发命令及显示结果进行了相应的说明，同时我们还看到了大量的有用信息。
