Basic System Management Commands

This chapter describes the function and displays the syntax for basic system management commands. For more information about defaults and usage guidelines, see the corresponding chapter of the Configuration Fundamentals Command Reference.

alias

To create a command alias, use the alias global configuration command. Use the no form of this command to delete all aliases in a command mode or to delete a specific alias, and to revert to the original command syntax.

mode	Command mode of the original and alias commands.
alias-name	Command alias.
alias-command-line	Original command syntax.

alias mode alias-name alias-command-line
no alias mode [alias-name]

mode

Command mode of the original and alias commands.

alias-name

Command alias.

alias-command-line

Original command syntax.

buffers

Use the buffers global configuration command to make adjustments to initial buffer pool settings and to the limits at which temporary buffers are created and destroyed. Use the no form of this command to return the buffers to their default size.

small	Buffer size of this public buffer pool is 104 bytes.
middle	Buffer size of this public buffer pool is 600 bytes.
big	Buffer size of this public buffer pool is 1524 bytes.
verybig	Buffer size of this public buffer pool is 4520 bytes.
large	Buffer size of this public buffer pool is 5024 bytes.
huge	Default buffer size of this public buffer pool is 18024 bytes. This value can be configured with the buffers huge size command.
type number	Interface type and interface number of the interface buffer pool. The type value cannot be fddi.
permanent	Number of permanent buffers that the system tries to create and keep. Permanent buffers are normally not trimmed by the system.
max-free	Maximum number of free or unallocated buffers in a buffer pool. A maximum of 20,480 small buffers can be constructed in the pool.
min-free	Minimum number of free or unallocated buffers in a buffer pool.
initial	Number of additional temporary buffers that are to be allocated when the system is reloaded. This keyword can be used to ensure that the system has necessary buffers immediately after reloading in a high-traffic environment.
number	Number of buffers to be allocated.

buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free
| min-free | initial} number
no buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free
| min-free | initial} number

small

Buffer size of this public buffer pool is 104 bytes.

middle

Buffer size of this public buffer pool is 600 bytes.

big

Buffer size of this public buffer pool is 1524 bytes.

verybig

Buffer size of this public buffer pool is 4520 bytes.

large

Buffer size of this public buffer pool is 5024 bytes.

huge

Default buffer size of this public buffer pool is 18024 bytes. This value can be configured with the buffers huge size command.

type number

Interface type and interface number of the interface buffer pool. The type value cannot be fddi.

permanent

Number of permanent buffers that the system tries to create and keep. Permanent buffers are normally not trimmed by the system.

max-free

Maximum number of free or unallocated buffers in a buffer pool.
A maximum of 20,480 small buffers can be constructed in the pool.

min-free

Minimum number of free or unallocated buffers in a buffer pool.

initial

Number of additional temporary buffers that are to be allocated when the system is reloaded. This keyword can be used to ensure that the system has necessary buffers immediately after reloading in a high-traffic environment.

number

Number of buffers to be allocated.

buffers huge size

Use the buffers huge size global configuration command to dynamically resize all huge buffers to the value you specify. Use the no form of this command to restore the default buffer values.

number	Huge buffer size, in bytes.

buffers huge size number
no buffers huge size number

number

Huge buffer size, in bytes.

calendar set

To set the system calendar, use one of the formats of the calendar set EXEC command.

hh:mm:ss	Current time in hours (military format), minutes, and seconds.
day	Current day (by date) in the month.
month	Current month (by name).
year	Current year (no abbreviation).

calendar set hh:mm:ss day month year
calendar set hh:mm:ss month day year

hh:mm:ss

Current time in hours (military format), minutes, and seconds.

day

Current day (by date) in the month.

month

Current month (by name).

year

Current year (no abbreviation).

clock calendar-valid

To configure a router as a time source for a network based on its calendar, use the clock calendar-valid global configuration command. Use the no form of this command to specify that the calendar is not an authoritative time source.

clock calendar-valid
no clock calendar-valid

clock read-calendar

To manually read the calendar into the system clock, use the clock read-calendar EXEC command.

clock read-calendar

clock set

To manually set the system clock, use one of the formats of the clock set EXEC command.

hh:mm:ss	Current time in hours (military format), minutes, and seconds.
day	Current day (by date) in the month.
month	Current month (by name).
year	Current year (no abbreviation).

clock set hh:mm:ss day month year
clock set hh:mm:ss month day year

hh:mm:ss

Current time in hours (military format), minutes, and seconds.

day

Current day (by date) in the month.

month

Current month (by name).

year

Current year (no abbreviation).

clock summer-time

To configure the system to automatically switch to summer time (daylight savings time), use one of the formats of the clock summer-time global configuration command. Use the no form of this command to configure the Cisco IOS software not to automatically switch to summer time.

zone	Name of the time zone (PDT,...) to be displayed when summer time is in effect.
recurring	Indicates that summer time should start and end on the corresponding specified days every year.
date	Indicates that summer time should start on the first specific date listed in the command and end on the second specific date in the command.
week	(Optional) Week of the month (1 to 5 or last).
day	(Optional) Day of the week (Sunday, Monday,...).
date	Date of the month (1 to 31).
month	Month (January, February,...).
year	Year (1993 to 2035).
hh:mm	Time (military format) in hours and minutes.
offset	(Optional) Number of minutes to add during summer time (default is 60).

clock summer-time zone recurring [week day month hh:mm week day month hh:mm [offset]]
clock summer-time zone date date month year hh:mm date month year hh:mm [offset]
clock summer-time zone date month date year hh:mm month date year hh:mm [offset]
no clock summer-time

zone

Name of the time zone (PDT,...) to be displayed when summer time is in effect.

recurring

Indicates that summer time should start and end on the corresponding specified days every year.

date

Indicates that summer time should start on the first specific date listed in the command and end on the second specific date in the command.

week

(Optional) Week of the month (1 to 5 or last).

day

(Optional) Day of the week (Sunday, Monday,...).

date

Date of the month (1 to 31).

month

Month (January, February,...).

year

Year (1993 to 2035).

hh:mm

Time (military format) in hours and minutes.

offset

(Optional) Number of minutes to add during summer time (default is 60).

clock timezone

To set the time zone for display purposes, use the clock timezone global configuration command. To set the time to Coordinated Universal Time (UTC), use the no form of this command.

zone	Name of the time zone to be displayed when standard time is in effect.
hours	Hours offset from UTC.
minutes	(Optional) Minutes offset from UTC.

clock timezone zone hours [minutes]
no clock timezone

zone

Name of the time zone to be displayed when standard time is in effect.

hours

Hours offset from UTC.

minutes

(Optional) Minutes offset from UTC.

clock update-calendar

To set the calendar from the system clock, use the clock update-calendar EXEC command.

clock update-calendar

downward-compatible-config

To generate a configuration that is compatible with an earlier Cisco IOS release, use the downward-compatible-config global configuration command. To remove this feature, use the no form of this command.

version	Cisco IOS Release number, not earlier than 10.2.

downward-compatible-config version
no downward-compatible-config

version

Cisco IOS Release number, not earlier than 10.2.

hostname

To specify or modify the host name for the network server, use the hostname global configuration command. The host name is used in prompts and default configuration filenames. The setup command facility also prompts for a host name at startup.

name	New host name for the network server.

hostname name

name

New host name for the network server.

ip bootp server

To access the BOOTP service available from hosts on the network, use the ip bootp server global configuration command. Use the no form of the command to disable these services.

ip bootp server
no ip bootp server

ip telnet source-interface

Use the ip telnet source-interface global configuration command to allow a user to select an address of an interface as the source address for Telnet connections. Use the no form of this command to reset the source address to the default for each connection.

interface	The interface whose address is to be used as the source for Telnet connections.

ip telnet source-interface interface
no ip telnet source-interface

interface

The interface whose address is to be used as the source for Telnet connections.

ip tftp source-interface

Use the ip tftp source-interface global configuration command to allow a user to select the interface whose address will be used as the source address for TFTP connections.

interface	The interface whose address is to be used as the source for TFTP connections.

ip tftp source-interface interface
no ip tftp source-interface

interface

The interface whose address is to be used as the source for TFTP connections.

load-interval

To change the length of time for which data is used to compute load statistics, use the load-interval interface configuration command. Use the no form of this command to revert to the default setting.

seconds	Length of time for which data is used to compute load statistics. A value that is a multiple of 30, from 30 to 600 (30, 60, 90, 120, and so forth).

load-interval seconds
no load-interval seconds

seconds

Length of time for which data is used to compute load statistics. A value that is a multiple of 30, from 30 to 600 (30, 60, 90, 120, and so forth).

ntp access-group

To control access to the system's Network Time Protocol (NTP) services, use the ntp access-group global configuration command. To remove access control to the system's NTP services, use the no form of this command.

query-only	Allows only NTP control queries. See RFC 1305 (NTP version 3).
serve-only	Allows only time requests.
serve	Allows time requests and NTP control queries, but does not allow the system to synchronize to the remote system.
peer	Allows time requests and NTP control queries and allows the system to synchronize to the remote system.
access-list-number	Number (1 to 99) of a standard IP access list.

ntp access-group {query-only | serve-only | serve | peer} access-list-number
no ntp access-group {query-only | serve-only | serve | peer}

query-only

Allows only NTP control queries. See RFC 1305 (NTP version 3).

serve-only

Allows only time requests.

serve

Allows time requests and NTP control queries, but does not allow the system to synchronize to the remote system.

peer

Allows time requests and NTP control queries and allows the system to synchronize to the remote system.

access-list-number

Number (1 to 99) of a standard IP access list.

ntp authenticate

To enable Network Time Protocol (NTP) authentication, use the ntp authenticate global configuration command. Use the no form of this command to disable the feature.

ntp authenticate
no ntp authenticate

ntp authentication-key

To define an authentication key for Network Time Protocol (NTP), use the ntp authentication-key global configuration command. Use the no form of this command to remove the authentication key for NTP.

number	Key number (1 to 4294967295).
md5	Authentication key. Message authentication support is provided using the Message Digest (MD5) algorithm. The key type md5 is currently the only key type supported.
value	Key value (an arbitrary string of up to eight characters).

ntp authentication-key number md5 value
no ntp authentication-key number

number

Key number (1 to 4294967295).

md5

Authentication key. Message authentication support is provided using the Message Digest (MD5) algorithm. The key type md5 is currently the only key type supported.

value

Key value (an arbitrary string of up to eight characters).

ntp broadcast

To specify that a specific interface should send Network Time Protocol (NTP) broadcast packets, use the ntp broadcast interface configuration command. Use the no form of this command to disable this capability.

version number	(Optional) Number from 1 to 3 indicating the NTP version.

ntp broadcast [version number]
no ntp broadcast

version number

(Optional) Number from 1 to 3 indicating the NTP version.

ntp broadcast client

To allow the system to receive NTP broadcast packets on an interface, use the ntp broadcast client interface configuration command. Use the no form of this command to disable this capability.

ntp broadcast client
no ntp broadcast client

ntp broadcastdelay

To set the estimated round-trip delay between the Cisco IOS software and a Network Time Protocol (NTP) broadcast server, use the ntp broadcastdelay global configuration command. Use the no form of this command to revert to the default value.

microseconds	Estimated round-trip time (in microseconds) for NTP broadcasts. The range is from 1 to 999999.

ntp broadcastdelay microseconds
no ntp broadcastdelay

microseconds

Estimated round-trip time (in microseconds) for NTP broadcasts. The range is from 1 to 999999.

ntp clock-period

value	Amount to add to the system clock for each clock hardware tick (in units of 2-32 seconds).

ntp clock-period value
no ntp clock-period

value

Amount to add to the system clock for each clock hardware tick (in units of
2-32 seconds).

ntp disable

To prevent an interface from receiving Network Time Protocol (NTP) packets, use the ntp disable interface configuration command. To enable receipt of NTP packets on an interface, use the no form of this command.

ntp disable
no ntp disable

ntp master

To configure the Cisco IOS software as a Network Time Protocol (NTP) master clock to which peers synchronize themselves when an external NTP source is not available, use the ntp master global configuration command. To disable the master clock function, use the no form of this command.

stratum	(Optional) Number from 1 to 15. Indicates the NTP stratum number that the system will claim.

ntp master [stratum]
no ntp master [stratum]

stratum

(Optional) Number from 1 to 15. Indicates the NTP stratum number that the system will claim.

ntp peer

To configure the system clock to synchronize a peer or to be synchronized by a peer, use the
ntp peer global configuration command. To disable this capability, use the no form of this command.

ip-address	IP address of the peer providing, or being provided, the clock synchronization.
version	(Optional) Defines the Network Time Protocol (NTP) version number.
number	(Optional) NTP version number (1 to 3).
key	(Optional) Defines the authentication key.
keyid	(Optional) Authentication key to use when sending packets to this peer.
source	(Optional) Names the interface.
interface	(Optional) Name of the interface from which to pick the IP source address.
prefer	(Optional) Makes this peer the preferred peer that provides synchronization.

ntp peer ip-address [version number] [key keyid] [source interface] [prefer]
no ntp peer ip-address

ip-address

IP address of the peer providing, or being provided, the clock synchronization.

version

(Optional) Defines the Network Time Protocol (NTP) version number.

number

(Optional) NTP version number (1 to 3).

key

(Optional) Defines the authentication key.

keyid

(Optional) Authentication key to use when sending packets to this peer.

source

(Optional) Names the interface.

interface

(Optional) Name of the interface from which to pick the IP source address.

prefer

(Optional) Makes this peer the preferred peer that provides synchronization.

ntp server

To allow the system clock to be synchronized by a time server, use the ntp server global configuration command. To disable this capability, use the no form of this command.

ip-address	IP address of the time server providing the clock synchronization.
version	(Optional) Defines the Network Time Protocol (NTP) version number.
number	(Optional) NTP version number (1 to 3).
key	(Optional) Defines the authentication key.
keyid	(Optional) Authentication key to use when sending packets to this peer.
source	(Optional) Identifies the interface from which to pick the IP source address.
interface	(Optional) Name of the interface from which to pick the IP source address.
prefer	(Optional) Makes this server the preferred server that provides synchronization.

ntp server ip-address [version number] [key keyid] [source interface] [prefer]
no ntp server ip-address

ip-address

IP address of the time server providing the clock synchronization.

version

(Optional) Defines the Network Time Protocol (NTP) version number.

number

(Optional) NTP version number (1 to 3).

key

(Optional) Defines the authentication key.

keyid

(Optional) Authentication key to use when sending packets to this peer.

source

(Optional) Identifies the interface from which to pick the IP source address.

interface

(Optional) Name of the interface from which to pick the IP source address.

prefer

(Optional) Makes this server the preferred server that provides synchronization.

ntp source

To use a particular source address in Network Time Protocol (NTP) packets, use the ntp source global configuration command. Use the no form of this command to remove the specified source address.

type	Type of interface.
number	Number of the interface.

ntp source type number
no ntp source

type

Type of interface.

number

Number of the interface.

ntp trusted-key

To authenticate the identity of a system to which Network Time Protocol (NTP) will synchronize, use the ntp trusted-key global configuration command. Use the no form of this command to disable authentication of the identity of the system.

key-number	Key number of authentication key to be trusted.

ntp trusted-key key-number
no ntp trusted-key key-number

key-number

Key number of authentication key to be trusted.

ntp update-calendar

To periodically update the calendar from Network Time Protocol (NTP), use the ntp update-calendar global configuration command. Use the no form of this command to disable the periodic updates.

ntp update-calendar
no ntp update-calendar

prompt

To customize the prompt, use the prompt global configuration command. To revert to the default prompt, use the no form of this command.

string	Prompt. It can consist of all printing characters and the escape sequences.

prompt string
no prompt [string]

string

Prompt. It can consist of all printing characters and the escape sequences.

scheduler allocate

To guarantee CPU time for processes, use the scheduler allocate global configuration command on the Cisco 7200 series and Cisco 7500 series. The no form of this command restores the default.

interrupt-time	Integer (in microseconds) that limits the maximum number of microseconds to spend on fast switching within any one network interrupt context. The range is 400 to 60000 microseconds. The default is 4000 microseconds.
process-time	Integer (in microseconds) that guarantees the minimum number of microseconds to spend at the process level when network interrupts are disabled. The range is 100 to 4000. The default is 200 microseconds.

scheduler allocate interrupt-time process-time
no scheduler allocate

interrupt-time

Integer (in microseconds) that limits the maximum number of microseconds to spend on fast switching within any one network interrupt context. The range is 400 to 60000 microseconds. The default is 4000 microseconds.

process-time

Integer (in microseconds) that guarantees the minimum number of microseconds to spend at the process level when network interrupts are disabled. The range is 100 to 4000. The default is 200 microseconds.

scheduler interval

To control the maximum amount of time that can elapse without running system processes, use the scheduler interval global configuration command. The no form of this command restores the default.

milliseconds	Integer that specifies the interval, in milliseconds. The minimum interval that you can specify is 500 milliseconds; there is no maximum value.

scheduler interval milliseconds
no scheduler interval

milliseconds

Integer that specifies the interval, in milliseconds. The minimum interval that you can specify is 500 milliseconds; there is no maximum value.

service decimal-tty

To specify that line numbers be displayed and interpreted as decimal numbers rather than octal numbers, use the service decimal-tty global configuration command. Use the no form of this command to restore the default.

service decimal-tty
no service decimal-tty

service exec-wait

To delay the startup of the EXEC on noisy lines, use the service exec-wait global configuration command. Use the no form of this command to disable the delay function.

service exec-wait
no service exec-wait

service finger

To allow Finger protocol requests (defined in RFC 742) to be made of the network server, use the service finger global configuration command. This service is equivalent to issuing a remote show users command. Use the no form of this command to remove this service.

service finger
no service finger

service hide-telnet-address

To hide addresses while trying to establish a Telnet session, use the service hide-telnet-address global configuration command. Use the no form of this command to remove this service.

service hide-telnet-address
no service hide-telnet-address

service nagle

To enable the Nagle congestion control algorithm, use the service nagle global configuration command. Use the no form of this command to disable the algorithm.

service nagle
no service nagle

service prompt config

To display the configuration prompt (config), use the service prompt config global configuration command. Use the no form of this command to remove the configuration prompt.

service prompt config
no service prompt config

service tcp-small-servers

To access minor TCP/IP services available from hosts on the network, use the service tcp-small-servers global configuration command. Use the no form of the command to disable these services.

service tcp-small-servers
no service tcp-small-servers

service telnet-zero-idle

To set the TCP window to zero (0) when the Telnet connection is idle, use the service telnet-zero-idle global configuration command. Use the no form of this command to disable this service.

service telnet-zero-idle
no service telnet-zero-idle

service udp-small-servers

To access minor User Datagram Protocol (UDP) services available from hosts on the network, use the service udp-small-servers global configuration command. Use the no form of the command to disable these services.

service udp-small-servers
no service udp-small-servers

show aliases

To display all alias commands, or the alias commands in a specified mode, use the show aliases EXEC command.

show aliases [mode]

mode

(Optional) Command mode. See the alias command for acceptable options for the mode argument.

show buffers

Use the show buffers EXEC command to display statistics for the buffer pools on the network server.

show buffers [type number | alloc [dump]]

type number

(Optional) Displays interface pool information. If the specified interface type and number has its own buffer pool, displays information for that pool. Value of type can be ethernet, serial, tokenring, fddi, bri, atm, e1, t1.

alloc

(Optional) Displays a brief listing of all allocated buffers.

dump

(Optional) Dumps all allocated buffers. This keyword must be used with the alloc keyword, not by itself.

show calendar

To display the calendar hardware setting, use the show calendar EXEC command:

show calendar

show clock

To display the system clock, use the show clock EXEC command.

show clock [detail]

detail

(Optional) Indicates the clock source (NTP, VINES, system calendar, and so forth) and the current summer-time setting (if any).

show ntp associations

To show the status of Network Time Protocol (NTP) associations, use the show ntp associations EXEC command.

show ntp associations [detail]

detail

(Optional) Shows detailed information about each NTP association.

show ntp status

To show the status of Network Time Protocol (NTP), use the show ntp status EXEC command.

show ntp status

show sntp

Use the show sntp EXEC command on a Cisco 1003, Cisco 1004, or Cisco 1005 router to show information about the Simple Network Time Protocol (SNTP).

show sntp

sntp broadcast client

Use the sntp broadcast client global configuration command to configure a Cisco 1003, Cisco 1004, or Cisco 1005 router to use the Simple Network Time Protocol (SNTP) to accept Network Time Protocol (NTP) traffic from any broadcast server. The no form of the command prevents the router from accepting broadcast traffic.

sntp broadcast client
no sntp broadcast client

sntp server

Use the sntp server global configuration command to configure a Cisco 1003, Cisco 1004, or Cisco 1005 router to use the Simple Network Time Protocol (SNTP) to request and accept Network Time Protocol (NTP) traffic from a time server. The no form of the command removes a server from the list of NTP servers.

sntp server {address | hostname} [version number]
no sntp server {address | hostname}

address

IP address of the time server.

hostname

Hostname of the time server.

version number

(Optional) Version of NTP to use. The default is 1.

type number	(Optional) Displays interface pool information. If the specified interface type and number has its own buffer pool, displays information for that pool. Value of type can be ethernet, serial, tokenring, fddi, bri, atm, e1, t1.
alloc	(Optional) Displays a brief listing of all allocated buffers.
dump	(Optional) Dumps all allocated buffers. This keyword must be used with the alloc keyword, not by itself.

address	IP address of the time server.
hostname	Hostname of the time server.
version number	(Optional) Version of NTP to use. The default is 1.

Table of Contents

Basic System Management Commands