Objective: To become familiar with the basic show commands.
Lab Equipment: We will be using Router 1. To select Router 1 click on the drop down
1. Get to the router prompt.
Router>
2. Enter Privilege Mode.
Router>enableRouter#
3. Show the active configuration in memory. The currently active configuration script
running on the router is referred to as the running-config on the routers command-line
interface. Note that privileged mode is required. The running configuration script is not
automatically saved on a Cisco router, and will be lost in the event of power failure. The
running configuration must be manually saved with the 'copy' command (discussed in a
later lab).
Router#show running-config
4. Flash memory is a special kind of memory on the router that contains the operating
system image file(s). Unlike regular router memory, Flash memory continues to maintain
the file image even after power is lost.
Router#show flash
5. The routers Command Line Interface (CLI) maintains by default the last 10 commands
you have entered in memory. What command will view all of the past commands still in
router memory at the same time?
Router#show history
6. What two commands will let you retrieve the previous command you typed?
Press the up arrowor<ctrl> P
7. What two commands will let you use the next command in the history buffer?
Press the down arrowor<ctrl> N
8. What command will let you view the status of the current layer 3 routed protocols
running on your router?
Router#show protocols
9. What command is used to obtain critical information, such as: router platform type,
operating system revision, operating system last boot time and file location, amount of
memory, number of interfaces, and configuration register?
Router#show version
10. How can you view the router’s clock?
Router#show clock
11. What command will display a cached list of hosts and all of their interfaces IP
addresses?
Router#show hosts
12. How can you view a list of all users who are connected to the router?
Router#show users
13. What command will give you detailed information about each interface?
Router#show interfaces
14. What command will show the global and interface-specific status of any layer 3
protocols?
Router#show protocols
Show Lab Summary
This lab will introduce the Cisco Internetwork Operating System (IOS) command line
interface (CLI). You will need to logon to a router and become familiar with the
different levels of access on the router. You will also become familiar with the
commands available to you in each mode (user or privileged) and the router help facility,
history, and editing features.
Show Version
The show version command gives you a lot more information than at first you may think.
Use show version to obtain critical information, such as: router platform type, operating
system revision, operating system last boot time and file location, amount of memory,
number of interfaces, and configuration register.
Router>show versionKrang Operating System SoftwareRouter uptime is 2 minutesSystem returned to ROM by power-onSystem image file is "flash:c2500.bin"[[[OUTPUT DELETED]]]1 Ethernet/IEEE 802.3 interface(s)1 Serial(sync/async) network interface(s)1 ISDN Basic Rate interface(s)32K bytes of non-volatile configuration memory.4096K bytes of processor board System flash (Read/Write)
Configuration register is 0x2102
Layer 3 Interface Information
To view the layer 3 information for all interfaces currently configured on the router, use
the show protocols command.
Router>show protocolsGlobal values:Internet Protocol routing is enabledBRI0 is administratively down, line protocol is DownEthernet0 is administratively down, line protocol is DownSerial0 is administratively down, line protocol is Down
Flash Memory
Flash memory is a special kind of memory on the router that contains the operating
system image file(s). Unlike regular router memory, Flash memory continues to maintain
the file image even after power is lost.
Router>show flash
System flash directory:File Length Name/status1 3015588 c2500.bin[3015652 bytes used, 1178652 available, 4194304 total]4096K bytes of processor board System flash (Read/Write)
Running Configuration
The currently active configuration script running on the router is referred to as the
running-config on the routers command-line interface. Note the privilege mode
required. The running configuration script is not automatically saved on a Cisco router,
and will be lost in the event of a power failure. The running configuration must be
manually saved with the copy command (discussed in a later lab).
Router>Router>enableRouter#show running-configBuilding configuration...
Current configuration:!version 12.0!hostname Router!interface Serial0no ip addressshutdown!interface BRI0no ip addressshutdown!interface Ethernet0no ip addressshutdown!line con 0line aux 0line vty 0 4!endRouter#
Command History
The routers Command Line Interface (CLI) maintains by default the last 10 commands
you have entered in memory, for later retrieval. You can change this default value. You
cycle through previous router commands entered (since the last power loss), using one of
two methods. To view all of the past commands still in router memory at the same time,
use the show history command. For single line retrieval, use either the Arrow-Up (for
previous command) and Arrow-Down (for next command), or Control-P (for previous
command) and Control-N (for next command).
Router>show historyshow versionshow protocolsshow flashenableshow running-configdisableshow history
Clock
The router keeps its own clock that you can use to synchronize devices to. To view the
clock use the show clock command.
Router#show clock*00:38:35.755 UTC Mon Mar 1 1993Router#
Host Table
You can create a list of host names on your router. You can view the entries (if any) by
typing show hosts.
Router#show hostsDefault domain is not setName/address lookup uses static mappingsHost Flags Age Type Address(es)Router#
Show users
The show users command displays users who are connected to the router.
Router#show usersLine User Host(s) Idle Location* 0 con 0 idle 00:00:00Router#
Show Interfaces
The show interfaces command will display statistics for all interfaces configured on the
router.
Router#show interfacesBRI0 is administratively down, line protocol is downHardware is BRIMTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255Encapsulation HDLC, loopback not setLast input never, output never, output hang neverLast clearing of "show interface" counters neverInput queue: 0/75/0 (size/max/drops); Total output drops: 0Queueing strategy: weighted fairOutput queue: 0/1000/64/0 (size/max total/threshold/drops)Conversations 0/0/256 (active/max active/max total)Reserved Conversations 0/0 (allocated/max allocated)5 minute input rate 0 bits/sec, 0 packets/sec5 minute output rate 0 bits/sec, 0 packets/sec0 packets input, 0 bytes, 0 no bufferReceived 0 broadcasts, 0 runts, 0 giants, 0 throttles0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort0 packets output, 0 bytes, 0 underruns0 output errors, 0 collisions, 5 interface resets0 output buffer failures, 0 output buffers swapped out0 carrier transitions--More--
Notice the --More-- This means that there is more information pertaining to the last
command. To view more commands line by line, press: enter To exit the output and
return to the router prompt, press: e (this can be any letter, it's just easy to remember that e is for exit) To view
more output one screen at a time, press the space bar.
Show Protocols
The show protocols command displays global and interface specific status of layer 3 routed
protocols.
Router#show protocolsGlobal values:Internet Protocol routing is enabledBRI0 is administratively down, line protocol is downEthernet0 is administratively down, line protocol is downSerial0 is administratively down, line protocol is downSerial1 is administratively down, line protocol is downSerial2 is administratively down, line protocol is down
