Table Of Contents
half-duplex controlled-carrier
loopback local (T1 controller)
loopback remote (T1 controller)
service-module 56k clock source
service-module 56k data-coding
service-module 56k network-type
service-module 56k remote-loopback
service-module 56k switched-carrier
service-module t1 clock source
service-module t1 remote-alarm-enable
service-module t1 remote-loopback
Interface Commands
This chapter contains the commands used to configure interface features that are not protocol-specific. For hardware technical descriptions, and for information about installing the router or access server interfaces, refer to the hardware installation and maintenance publication for your particular product.
For interface configuration tasks and examples, refer to the chapter entitled "Configuring Interfaces" in the Configuration Fundamentals Configuration Guide.
For information about the Channel Interface Processor (CIP), see the chapter entitled "IBM Channel Attach Commands" chapter in the Bridging and IBM Networking Command Reference. The CIP is described in a separate chapter because of the interrelationship of host system configuration values and device configuration values.
Note
Some commands previously documented in this chapter have been replaced by new commands. Although they continue to perform their normal functions in the current release, support for these commands will cease in a future release.
access-list (standard)
Use the access-list global configuration command to establish MAC address access lists. Use the no form of this command to remove a single access list entry.
access-list access-list-number {permit | deny} address mask
no access-list access-list-numberSyntax Description
Default
No MAC address access lists are established.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Related Command
access-list (type-code)
access-list (type-code)
Use the access-list global configuration command to build type-code access lists. Use the no form of this command to remove a single access list entry.
access-list access-list-number {permit | deny} type-code wild-mask
no access-list access-list-numberSyntax Description
Default
No type-code access lists are built.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Type-code access lists can have an impact on system performance; therefore, keep the lists as short as possible and use wildcard bit masks whenever possible.
Access lists are evaluated according to the following algorithm:
•
•
If the length/type field is greater than 1500, the packet is treated as an LSAP packet unless the DSAP and SSAP fields are AAAA. If the latter is true, the packet is treated using type-code filtering.
If you have both Ethernet Type II and LSAP packets on your network, you should set up access lists for both.
Use the last item of an access list to specify a default action; for example, permit everything else or deny everything else. If nothing else in the access list matches, the default action is normally to deny access; that is, filter out all other type codes.
Related Commands
access-list (extended)
access-list (standard)async default ip address
The peer default ip address command replaces the async default ip address command. Refer to the description of the peer default ip address command for more information.
async default routing
To enable the router to pass routing updates to other routers over the AUX port configured as an asynchronous interface, use the async default routing interface configuration command.
async default routing
Syntax Description
This command has no keywords or arguments.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use the async default routing command to define the default behavior for router-to-router communication over connections to the AUX port configured as an asynchronous interface.
To require a remote user to manually configure routing over connections to the AUX port configured as an asynchronous interface, use the async dynamic routing command.
Example
The following example enables routing over asynchronous interface 0:
interface async 0async default routingRelated Command
async dynamic routing
async dynamic address
To specify an address on an asynchronous interface (rather than using the default address), use the async dynamic address interface configuration command. Use the no form of this command to disable dynamic addressing.
async dynamic address
no async dynamic addressSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Example
The following example shows dynamic addressing assigned to an interface:
interface async 1async dynamic addressRelated Commands
A dagger (†) indicates that the command is documented outside this chapter.
ppp †
slipasync dynamic routing
To enable manually configured routing on an asynchronous interface, use the async dynamic routing interface configuration command. Use the no form of this command to disable routing protocols; static routing is still used.
async dynamic routing
no async dynamic routingSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Example
The following example shows how to enable manually configured routing on asynchronous interface 1. The ip tcp header-compression passive command enables Van Jacobson TCP header compression and prevents transmission of compressed packets until a compressed packet arrives from the asynchronous link.
interface async 1 async dynamic routing async dynamic addressasync default ip address 1.1.1.2 ip tcp header-compression passiveA remote user who establishes a PPP or SLIP connection to this asynchronous interface can enable routing by using the /routing switch or the ppp/routing command.
However, if you want to establish routing by default on connections to an asynchronous interface, use the async default routing command when you configure the interface.
Related Commands
A dagger (†) indicates that the command is documented outside this chapter.
async default routing
async dynamic address
ip tcp header-compression †async mode dedicated
To place a line into network mode using SLIP or PPP encapsulation, use the async mode dedicated interface configuration command. Use the no form of this command to return the line to interactive mode.
async mode dedicated
no async modeSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
With dedicated asynchronous mode, the interface will use either SLIP or PPP encapsulation, depending on which encapsulation method is configured for the interface. An EXEC prompt does not appear, and the line is not available for normal interactive use.
If you configure a line for dedicated mode, you will not be able to use async dynamic address, because there is no user prompt. You must configure either async default ip address and ip unnumbered or ip address.
Example
The following example assigns an Internet address to an asynchronous line and places the line into network mode. Setting the stop bits to 1 enhances performance.
interface async 1async default ip address 182.32.7.51async mode dedicatedencapsulation slipRelated Command
async mode interactive
async mode interactive
To enable the use of slip and ppp EXEC commands, use the async mode interactive line configuration command. Use the no form of this command to prevent users from enabling SLIP and PPP at the EXEC level.
async mode interactive
no async modeSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Example
The following example enables the ppp and slip EXEC commands:
interface async 1async mode interactiveRelated Commands
A dagger (†) indicates that the command is documented outside this chapter.
async mode dedicated
ppp †
slip †auto-polarity
To enable automatic receiver polarity reversal on a hub port connected to an Ethernet interface of a Cisco 2505 or Cisco 2507, use the auto-polarity hub configuration command. To disable this feature, use the no form of this command.
auto-polarity
no auto-polaritySyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Hub configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
This command applies to a port on an Ethernet hub only.
Example
The following example enables automatic receiver polarity reversal on hub 0, ports 1 through 3:
hub ethernet 0 1 3auto-polarityRelated Command
hub
backup delay
To define how much time should elapse before a secondary line status changes after a primary line status has changed, use the backup delay interface configuration command. To return to the default, so that as soon as the primary fails, the secondary is immediately brought up without delay, use the no form of this command.
backup delay {enable-delay | never} {disable-delay | never}
no backup delay {enable-delay | never} {disable-delay | never}Syntax Description
Default
0 seconds
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When a primary line goes down, the Cisco IOS software delays the amount of seconds defined by the enable-delay argument before enabling the secondary line. If, after the delay period, the primary line is still down, the secondary line is activated.
When a primary line comes back up, the software will delay the amount of seconds defined by the disable-delay argument.
In cases where spurious signal disruptions might appear as intermittent lost carrier signals, it is recommended that some delay be enabled before activating and deactivating a secondary.
ExamplesThe following example sets a 10-second delay on deactivating the secondary line; however, the line is activated immediately:
interface serial 0backup delay 0 10The same example on the Cisco 7000 requires the following commands:
backup interface serial
To configure the serial interface as a secondary, or dial backup line, use the backup interface serial interface configuration command. Use the no form of this command to turn disable this feature.
backup interface serial number
backup interface serial slot/port (for the Cisco 7000 series and 7200 series)
no backup interface serial number
no backup interface serial slot/port (for the Cisco 7000 series and 7200 series)Syntax Description
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0. (An earlier command, backup interface, first appeared in Cisco IOS Release 10.0.)
Examples
The following example sets serial 1 as the backup line to serial 0:
interface serial 0backup interface serial 1Related Command
down-when-looped
backup load
To set the traffic load thresholds for dial backup service, use the backup load interface configuration command. Use the no form of this command to remove the setting.
backup load {enable-threshold | never} {disable-load | never}
no backup load {enable-threshold | never} {disable-load | never}Syntax Description
Default
Both arguments default to never.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When the transmitted or received load on the primary line is greater than the value assigned to the enable-threshold argument, the secondary line is enabled.
When the transmitted load on the primary line plus the transmitted load on the secondary line is less than the value entered for the disable-load argument, and the received load on the primary line plus the received load on the secondary line is less than the value entered for the disable-load argument, the secondary line is disabled.
If the never keyword is used instead of an enable-threshold value, the secondary line is never activated because of load. If the never keyword is used instead of a disable-load value, the secondary line is never deactivated because of load.
Examples
The following example sets the traffic load threshold to 60 percent on the primary line. When that load is exceeded, the secondary line is activated, and will not be deactivated until the combined load is less than 5 percent of the primary bandwidth.
interface serial 0backup load 60 5The same example on the Cisco 7000 requires the following commands:
bandwidth
To set a bandwidth value for an interface, use the bandwidth interface configuration command. Use the no form of this command to restore the default values.
bandwidth kilobits
no bandwidthSyntax Description
kilobits
Intended bandwidth in kilobits per second. For a full bandwidth DS3, enter the value 44736.
Default
Default bandwidth values are set during startup and can be displayed with the EXEC command show interfaces.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The bandwidth command sets an informational parameter only; you cannot adjust the actual bandwidth of an interface with this command. For some media, such as Ethernet, the bandwidth is fixed; for other media, such as serial lines, you can change the actual bandwidth by adjusting hardware. For both classes of media, you can use the bandwidth configuration command to communicate the current bandwidth to the higher-level protocols.
Additionally, IGRP uses the minimum path bandwidth to determine a routing metric. The TCP protocol adjusts initial retransmission parameters based on the apparent bandwidth of the outgoing interface.
At higher bandwidths, the value you configure with the bandwidth command is not what is displayed by the show interface command. The value shown is that used in IGRP updates and also used in computing load.
Note
Example
The following example sets the full bandwidth for DS3 transmissions:
interface serial 0 bandwidth 44736Related Command
A dagger (†) indicates that the command is documented outside this chapter.
vines metric †
cablelength
To increase the pulse of a signal at the receiver and decrease the pulse from the transmitter using pulse equalization and line build-out for a T1 cable on a Cisco AS5200, use the cablelength controller configuration command. To return the pulse equalization and line build-out values to their default settings, use the no form of this command.
cablelength long dbgain-value dbloss-value
no cablelength longSyntax Description
Default
Long cable length, receiver gain of 36 dB, and transmitter loss of 0 dB
Command Mode
Controller configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Use this command for configuring the T1 controller only if the Cisco AS5200's T1 line does not connect to an external CSU box. Ask your telephone service provider what decibel option to use when connecting the T1 line to a smart jack.
A pulse equalizer regenerates a signal that has been attenuated and filtered by a cable loss. Pulse equalization does not produce a simple gain, but it filters the signal to compensate for complex cable loss. A gain26 receiver gain compensates for a long cable length equivalent to 26 dB of loss, while a gain36 compensates for 36 dB of loss.
The lengthening or building out of a line is used to control far-end crosstalk. Building out attenuates the stronger signal from the customer installation transmitter so that the transmitting and receiving signals have similar amplitudes. A signal difference of less than 7.5 dB is ideal. Building out does not produce simple flat loss (also known as resistive flat loss). Instead, it simulates a cable loss of 7.5 dB, 15 dB, or 22.5 dB so that the resulting signal is handled properly by the receiving equalizer at the other end.
Example
The following example increases the receiver gain by 26 decibels and decreases the transmitting pulse by 7.5 decibels for a long cable:
cablelength long gain26 -7.5dbcas-group
To configure channelized T1 timeslots with channel associated signaling (also known as robbed bit signaling), which enables an integrated modem to receive and transmit analog calls, use the cas-group controller configuration command. Use the no form of this command to disable channel associated signaling for one or more timeslots.
cas-group channel-group [timeslots range]
no cas-group channel-group [timeslots range]Syntax Description
Default
Disabled
Command Mode
Controller configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Use this command to enable an AS5200 modem to receive and send incoming and outgoing analog calls through each T1 controller that is configured for a channelized T1 line, which has 24 possible channels.
Switched 56 digital calls are not supported under this new feature.
Example
The following example shows you how to configure all 24 channels to support robbed bit signaling on a Cisco AS5200:
AS5200(config)# controller T1 0AS5200(config-controller)# cas-group 1 timeslots 1-24AS5200(config-controller)#%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 1 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 2 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 3 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 4 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 5 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 6 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 7 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 8 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 9 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 10 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 11 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 12 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 13 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 14 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 15 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 16 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 17 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 18 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 19 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 20 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 21 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 22 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 23 is up%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 24 is upchannel-group
Use the channel-group controller configuration command to define the timeslots that belong to each T1 or E1 circuit.
channel-group number timeslots range [speed {48 | 56 | 64}]
Syntax Description
Default
The default line speed when configuring a T1 controller is 56 kbps.
The default line speed when configuring an E1 controller is 64 kbps.
Command Mode
Controller configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use this command in configurations where the router or access server must communicate with a T1 or E1 fractional data line. The channel-group number may be arbitrarily assigned and must be unique for the controller. The timeslot range must match the timeslots assigned to the channel group. The service provider defines the timeslots that comprise a channel group.
Example
In the following example, three channel groups are defined. Channel-group 0 consists of a single timeslot, channel-group 8 consists of 7 timeslots and runs at a speed of 64 kbps per timeslot, and channel-group 12 consists of a single timeslot.
channel-group 0 timeslots 1channel-group 8 timeslots 5,7,12-15,20 speed 64channel-group 12 timeslots 2Related Commands
framing
linecodeclear controller
Use the clear controller EXEC command to reset the T1 or E1 controller on the Cisco 7000 series, Cisco 7200 series, or Cisco 4000 series routers.
clear controller {t1 | e1} slot/port (Cisco 7000 series and Cisco 7200 series)
clear controller {t1 | e1} number (Cisco 4000 series)Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0 (for the Cisco 7000).
This command first appeared in Cisco IOS Release 11.0 (for the Cisco 4000).Examples
The following example resets the T1 controller at slot 4, port 0 on a Cisco 7000 series router:
clear controller t1 4/0The following example resets the E1 controller at NIM 0 on a Cisco 4000 series router:
clear controller e1 0Related Commands
controller e1
controller t1clear controller lex
To reboot the LAN Extender chassis and restart its operating software, use the clear controller lex privileged EXEC command.
clear controller lex number [prom]
clear controller lex slot/port [prom] (for the Cisco 7000 family)Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
The clear controller lex command halts operation of the LAN Extender and performs a cold restart.
Without the prom keyword, if an image exists in Flash memory, and that image has a newer software version than the PROM image, and that image has a valid checksum, then this command runs the Flash image. If any one of these three conditions is not met, this command reloads the PROM image.
With the prom keyword, this command reloads the PROM image, regardless of any Flash image.
Examples
The following example halts operation of the LAN Extender bound to LAN Extender interface 2 and causes the LAN Extender to perform a cold restart from Flash memory:
Router# clear controller lex 2reload remote lex controller? [confirm] yesThe following example halts operation of the LAN Extender bound to LAN Extender interface 2 and causes the LAN Extender to perform a cold restart from PROM:
Router# clear controller lex 2 promreload remote lex controller? [confirm] yesclear counters
To clear the interface counters, use the clear counters EXEC command.
clear counters [type number]
clear counters [type slot/port] [ethernet | serial] (for the Cisco 4000 series or Cisco 7000 series with a LAN Extender interface)
clear counters [type slot/port] (for the Cisco 7000 series and Cisco 7200 series, and for the Cisco 7500 with a Packet over SONET Interface Processor)
clear counters [type slot/port-adapter/port] (for the Cisco 7000 series and the Cisco 7500 series with ports on VIP cards)Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command clears all the current interface counters from the interface unless the optional arguments type and number are specified to clear only a specific interface type (serial, Ethernet, Token Ring, and so on).
Note
Examples
The following example illustrates how to clear all interface counters:
clear countersThe following example illustrates how to clear interface counters on the serial interface residing on a Cisco 1000 series LAN Extender:
clear counters lex 0 serialRelated Command
show interfaces
clear hub
To reset and reinitialize the hub hardware connected to an interface of a Cisco 2505 or Cisco 2507, use the clear hub ethernet EXEC command.
clear hub ethernet number
ethernet
Indicates the hub in front of an Ethernet interface.
number
Hub number to clear, starting with 0. Since there is currently only one hub, this number is 0.
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Example
The following example clears hub 0:
clear hub ethernet 0Related Command
hub
clear hub counters
To set to zero the hub counters on an interface of a Cisco 2505 or Cisco 2507, use the clear hub counters EXEC command.
clear hub counters [ether number [port [end-port]]]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Example
The following example clears the counters displayed in a show hub command for all ports on hub 0:
clear hub counters ether 0Related Command
show hub
clear interface
To reset the hardware logic on an interface, use the clear interface EXEC command.
clear interface type number
clear interface type slot/port (on a Cisco 7000 series and Cisco 7200 series, and for the Cisco 7500 with a Packet over SONET Interface Processor)
clear interface [type slot/port-adapter/port] (for ports on VIP cards in the Cisco 7000 series and the Cisco 7500 series routers)
clear interface type slot/port [:channel-group] (on a Cisco 7000 MIP T1 interface)Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Under normal circumstances, you do not need to clear the hardware logic on interfaces.
Example
The following example resets the interface logic on HSSI interface 1:
clear interface hssi 1clear interface fastethernet
To reset the controller for a specified Fast Ethernet interface, use the clear interface fastethernet privileged EXEC command.
clear interface fastethernet number (Cisco 4500 series)
clear interface fastethernet slot/port (Cisco 7000 series and Cisco 7200 series)
clear interface fastethernet slot/port-adapter/port (Cisco 7500 series)Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Examples
The following example resets the controller for the Ethernet 0 interface on a Cisco 4500:
clear interface fastethernet 0The following example resets the controller for the Ethernet interface located in slot 1 port 0 on a Cisco 7000 or Cisco 7200:
clear interface fastethernet 1/0The following example resets the controller for the Ethernet interface located in slot 1 port adapter 0 port 0 on a Cisco 7500:
clear interface fastethernet 1/0/0clear line
To return a line to its idle state, use the clear line privileged EXEC command at the system prompt.
clear line line-number
Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Normally, this command returns the line to its default as a terminal line, with the interface in a "down" state.
Example
The following example shows how to use the clear line command to return serial interface 5 to its idle state:
clear line 5clear rif-cache
To clear entries from the Routing Information Field (RIF) cache, use the clear rif-cache EXEC command.
clear rif-cache
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Example
The following example illustrates how to clear the RIF cache:
clear rif-cacheRelated Command
A dagger (†) indicates that the command is documented outside this chapter.
multiring †
clear service-module serial
To reset the integrated CSU/DSU on a Cisco 2524 or Cisco 2525 router, use the clear service-module serial privileged EXEC configuration command.
clear service-module serial number
Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Use this command only in severe circumstances (for example, when the router is not responding to a CSU/DSU configuration command).
This command terminates all DTE and line loopbacks that are locally or remotely configured. It also interrupts data transmission through the router for up to 15 seconds. The software performs an automatic software reset in case of two consecutive configuration failures.
The CSU/DSU module is not reset with the clear interface command.
CautionIf you experience technical difficulties with your router and intend to contact customer support, refrain from using this command. This command erases the router's past CSU/DSU performance statistics. To clear only the CSU/DSU performance statistics, issue the clear counters command.
Example
The following example resets the CSU/DSU on a Cisco 2524 or Cisco 2525 router:
clear service-module serial 0Related Commands
clear counters
test service-moduleclock rate
To configure the clock rate for the hardware connections on the serial interface appliques, network interface modules (NIMs), and interface processors to an acceptable bit rate, use the clock rate interface configuration command. Use the no clock rate command to remove the clock rate if you change the interface from a DCE to a DTE device.
clock rate bps
no clock rateSyntax Description
bps
Desired clock rate in bits per second: 1200, 2400, 4800, 9600, 19200, 38400, 56000, 64000, 72000, 125000, 148000, 500000, 800000, 1000000, 1300000, 2000000, or 4000000.
Default
No clock rate is configured.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Be aware that the fastest speeds might not work if your cable is too long, and that speeds faster than 148,000 bits per second are too fast for EIA/TIA-232 signaling. It is recommended that you only use the synchronous serial EIA/TIA-232 signal at speeds up to 64,000 bits per second. To permit a faster speed, use an EIA/TIA-449 or V.35 applique.
Example
The following example sets the clock rate on the first serial interface to 64,000 bits per second:
interface serial 0 clock rate 64000clock source (Cisco AS5200)
To select the clock source for the time-division multiplexing (TDM) bus in a Cisco AS5200 access server, use the clock source interface configuration command. The no form of this command configures the clock source to its default setting.
clock source {line {primary | secondary} | internal}
no clock source line {primary | secondary}Syntax Description
Defaults
Primary TDM clock source from the T1 0 controller
Secondary TDM clock source from the T1 1 controller
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
To use the clocking coming in from a T1 line, configure the clock source line primary command on the T1 interface that has the most reliable clocking. Configure the clock source line secondary command on the T1 interface that has the next best known clocking. With this configuration, the primary line clocking is backed up to the secondary line if the primary clocking shuts down.
Example
The following example configures the Cisco AS5200 access server to use T1 controller 0 as the primary clock source and T1 controller 1 as the secondary clock source:
controller t1 0clock source line primarycontroller t1 1clock source line secondaryclock source (controller)
Use the clock source controller configuration command to set the T1-line clock-source for the MIP in the Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series or for the NPM in the Cisco 4000 series.
clock source {line | internal}
Syntax Description
