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Cisco IOS Interface and Hardware Component Command Reference, Release 12.3 T
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Introduction
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Interface and Hardware Component Commands: A through C
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Interface and Hardware Component Commands: D through H
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Interface and Hardware Component Commands: I through L
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int_m1gt_1
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Interface and Hardware Component Commands: M through R
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Interface and Hardware Component Commands: scramble through show chassis
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Interface and Hardware Component Commands: show compress through show hub
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Interface and Hardware Component Commands: show interfaces through show interfaces vg-anylan
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Interface and Hardware Component Commands: show ipc through syscon source-interface
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Interface and Hardware Component Commands: T through Y
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Table Of Contents
dsl-mode shdsl symmetric annex
end (satellite initial configuration)
exit (satellite initial configuration)
half-duplex controlled-carrier
hw-module main-cpu qa error-recovery
data-protection
To enable data protection for a circuit emulation (CEM) channel, use the data-protection command in CEM configuration mode. To disable data protection, use the no form of this command.
data-protection
no data-protection
Syntax Description
This command has no arguments or keywords.
Defaults
Data protection is disabled.
Command Modes
CEM configuration
Command History
Examples
The following example demonstrates how to enable data protection.
Router(config-cem)# data-protectionRelated Commands
cem
Enters circuit emulation configuration mode.
clear cem
Clears CEM channel statistics.
show cem
Displays CEM channel statistics.
data-strobe
To specify an input control lead to be monitored as an indicator of valid data, use the data-strobe command in CEM configuration mode. To disable the monitoring of an input control lead, use the no form of this command.
data-strobe input-lead {on | off}
no data-strobe
Syntax Description
Defaults
No input control lead is monitored.
Command Modes
CEM configuration
Command History
Usage Guidelines
Any input control signal on a serial data port may be configured as a "data strobe" to indicate to the NM-CEM-4SER network module whether ingress data on the port should be encapsulated for transmission or ignored. If the data strobe command is specified with the on keyword, data packets are created and sent when the input lead is asserted. If the data strobe is off (either intentionally, or as a result of the failure of the customer premises equipment [CPE]), no data packets are created, and this results in preservation of bandwidth in the IP network.
This command applies only to serial ports.
Examples
The following example demonstrates how to specify that packets are to be created and sent to the far end only when the DTR input control lead is asserted.
Router(config-cem)# data-strobe dtr on
Related Commands
dce-terminal-timing enable
To prevent phase shifting of the data with respect to the clock when running the line at high speeds and long distances, use the dce-terminal-timing enable command in interface configuration mode. If serial clock transmit external (SCTE) terminal timing is not available from the DTE, use the no form of this command; the DCE will use its own clock instead of SCTE from the DTE.
dce-terminal-timing enable
no dce-terminal-timing enable
Syntax Description
This command has no arguments or keywords.
Defaults
The DCE uses its own clock.
Command Modes
Interface configuration
Command History
Usage Guidelines
On the Cisco 4000 router, you can specify the serial Network Interface Module timing signal configuration. When the board is operating as a DCE and the DTE provides terminal timing (SCTE or TT), the dce-terminal-timing enable command causes the DCE to use SCTE from the DTE.
Examples
The following example shows how to prevent phase shifting of the data with respect to the clock:
Router(config)# interface serial 0Router(config-if)# dce-terminal-timing enabledefault (CEM)
To reset channel options to their default values, use the default command in CEM configuration mode.
default {data-protection | dejitter-buffer | idle-pattern | ip dscp | ip tos | ip precedence | payload-compression | payload-size | signaling}
Syntax Description
Defaults
The CEM channel options are set at their configured values.
Command Modes
CEM configuration
Command History
Examples
The following example demonstrates how to reset CEM channel data protection to its default value.
Router(config-cem)# default data-protectionRelated Commands
dejitter-buffer
To configure the size of the dejitter buffer, use the dejitter-buffer command in CEM configuration mode. To restore the dejitter buffer to its default size, use the no form of this command.
dejitter-buffer size
no dejitter-buffer
Syntax Description
Defaults
The dejitter buffer defaults to 60 milliseconds.
Command Modes
CEM configuration
Command History
Examples
The following example shows how to set the dejitter buffer to 200 milliseconds.
Router(config-cem)# dejitter-buffer 200
Related Commands
cem
Enters circuit emulation configuration mode.
clear cem
Clears CEM channel statistics.
show cem
Displays CEM channel statistics.
delay (interface)
To set a delay value for an interface, use the delay command in interface configuration mode. To restore the default delay value, use the no form of this command.
delay tens-of-microseconds
no delay
Syntax Description
tens-of-microseconds
Integer that specifies the delay in tens of microseconds for an interface or network segment. To see the default delay, use the show interfaces command.
Defaults
Default delay values may be displayed with the show interfaces EXEC command.
Command Modes
Interface configuration
Command History
Examples
The following example shows how to set a delay of 30,000 microseconds on serial interface 3:
Router(config)# interface serial 3Router(config-if)# delay 3000Related Commands
show interfaces
Displays the statistical information specific to a serial interface.
description (controller)
To add a description to an E1 or T1 controller or the Channelized T3 Interface Processor (CT3IP) in Cisco 7500 series routers, use the description command in controller configuration mode. To remove the description, use the no form of this command.
description string
no description
Syntax Description
string
Comment or description (up to 80 characters) to help you remember what is attached to an interface.
Defaults
No description is added.
Command Modes
Controller configuration
Command History
10.3
This command was introduced.
11.3
This command was modified to include the CT3IP controller.
Usage Guidelines
The description command is meant solely as a comment to be put in the configuration to help you remember what certain controllers are used for. The description affects the CT3IP and Multichannel Interface Processor (MIP) interfaces only and appears in the output of the show controller e1, show controller t1, show controller t3, and show running-config EXEC commands.
Examples
The following example shows how to add a description for a 3174 controller:
Router(config)# controller t1Router(config-controller)# description 3174 Controller for test labRelated Commands
dot1q tunneling ethertype
To define the Ethertype field type used by peer devices when implementing Q-in-Q VLAN tagging, use the dot1q tunneling ethertype command in interface configuration mode. To remove the VLAN tag Ethertype, use the no form of this command.
dot1q tunneling ethertype ethertype
no dot1q tunneling ethertype ethertype
Syntax Description
Defaults
The Ethertype field used by peer devices when implementing Q-in-Q VLAN tagging is 0x8100.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the dot1q tunneling ethertype command if the peer switching devices are using an Ethertype field value of 0x9100. All Cisco switching devices use the default Ethertype field value of 0x8100.
This command is used with the IEEE 802.1Q-in-Q VLAN Tag Termination feature in which double VLAN tagging is configured using the encapsulation dot1q command. 802.1q double tagging allows a service provider to use a single VLAN to support customers who have multiple VLANs.
Examples
The following example shows how to configure an Ethertype field as 0x9100:
Router(config)# interface gigabitethernet 1/0/0Router(config-if)# dot1q tunneling ethertype 0x9100Related Commands
down-when-looped
To configure an interface to inform the system that it is down when loopback is detected, use the down-when-looped command in interface configuration mode.
down-when-looped
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is valid for High-Level Data Link Control (HDLC) or PPP encapsulation on serial and High-Speed Serial Interface (HSSI) interfaces.
This command does not have a no form.
Backup Interfaces
When an interface has a backup interface configured, it is often desirable that the backup interface be enabled when the primary interface is either down or in loopback. By default, the backup is enabled only if the primary interface is down. By using the down-when-looped command, the backup interface will also be enabled if the primary interface is in loopback.
Testing an Interface with the Loopback Command
If testing an interface with the loopback command, or by placing the DCE into loopback, the down-when-looped command should not be configured; otherwise, packets will not be transmitted out the interface that is being tested.
Examples
The following example shows how to configure interface serial 0 for HDLC encapsulation. The interface is then configured to let the system know that it is down when in loopback mode.
Router(config)# interface serial0Router(config-if)# encapsulation hdlcRouter(config-if)# down-when-loopedRelated Commands
backup interface
Configures an interface as a secondary or dial backup interface.
loopback (E3 controller)
Diagnoses equipment malfunctions between an interface and a device.
ds0-group (J1 controller)
To configure channelized J1 time slots, use the ds0-group command in controller configuration mode. To remove the DS0 group, use the no form of this command.
ds0-group ds0-group-no timeslots timeslot-list type external-signaling
no ds0-group ds0-group-no timeslots timeslot-list type external-signaling
Syntax Description
Defaults
No DS0 group is defined.
Command Modes
Controller configuration
Command History
Usage Guidelines
The ds0-group command replaces the existing cas-group command. Making the command generic allows flexibility and scalability. It is not restricted to channel associated signaling (CAS) or channel bundling.
The ds0-group command automatically creates a logical voice port that is numbered as follows on Cisco 2600 and Cisco 3600 series routers: slot/port:ds0-group-no. Although only one voice port is created for each group, applicable calls are routed to any channel in the group.
Examples
The following example is sample output from the show controllers j1 command on the Cisco 3660 series after channelized J1 time slots have been configured:
Router(config-controller)# ds0-group 1 timeslots 1-15,17-31 type e&m-wink-startRouter(config-controller)# endRouter# show controllers j1*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(1), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(2), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(3), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(4), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(5), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(6), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(7), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(8), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(9), cp*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(10), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(11), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(12), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(13), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(14), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(15), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(17), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(18), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(19), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(20), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(21), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(22), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(23), p*Mar 1 03:12:26.259: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(24), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(25), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(26), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(27), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(28), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(29), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(30), p*Mar 1 03:12:26.263: %LINK-3-UPDOWN: Interface recEive and transMit3/0:0(31), pRelated Commands
dsl-mode shdsl symmetric annex
To specify the operating mode of the digital subscriber line (DSL) controller, use the dsl-mode shdsl symmetric annex command in controller configuration mode. To return the DSL to the default Annex A, use the no form of this command.
dsl-mode shdsl symmetric annex mode
Syntax Description
Defaults
The annex defaults to A for North America.
Command Modes
Controller configuration
Command History
Usage Guidelines
This command is used to configure the DSL controller interface to operate in a specified DSL mode and to set regional operating parameters. The shdsl keyword is used to set the mode to SHDSL and configures multirate, high-speed DSL per ITU G.991.2. The symmetric keyword configures the controller to symmetric mode. The annex keyword configures the controller to use regional operating parameters. The regional operating parameters default to North America.
Examples
The following example displays the use of the controller dsl 0/0 command to configure the controller in the router configured on the central office (CO) side. Use the dsl-mode shdsl symmetric annex b command to configure the controller for multirate, high-speed DSL with symmetric mode for European operating parameters.
Router# configure terminalRouter(config)# controller dsl 0/0Router(config-controller)# line-term coRouter(config-controller)# dsl-mode shdsl symmetric annex bRouter(config-controller)# mode atmRouter(config-controller)#00:22:07: %CONTROLLER-5-UPDOWN: Controller DSL 0/0, changed state to downRouter(config-controller)# line-mode 4-wire00:23:25: %CONTROLLER-5-UPDOWN: Controller DSL 0/0, changed state to up00:23:31: %LINK-3-UPDOWN: Interface ATM0/0, changed state to up00:23:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0/0, changed state to upRelated Commands
dsu bandwidth
To specify the maximum allowable bandwidth used by a T3 or E3 controller or the PA-T3 and PA-E3 port adapters, use the dsu bandwidth command in interface configuration mode. To return to the default bandwidth, use the no form of this command.
dsu bandwidth kbps
no dsu bandwidth
Syntax Description
kbps
Maximum bandwidth, in kbps. Range is from 22 to 44736. Default values are as follows:
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34010 for E3 or PA-E3
•
•
Defaults
34010 kbps for E3 or PA-E3
44210 kbps for T3
44736 kbps for PA-T3Command Modes
Interface configuration
Command History
Usage Guidelines
The local interface configuration must match the remote interface configuration. For example, if you reduce the maximum bandwidth to 16000 on the local port, you must also do the same on the remote port.
The dsu bandwidth command reduces the bandwidth by padding the E3 and T3 frame.
To verify the data service unit (DSU) bandwidth configured on the interface, use the show interfaces serial EXEC command.
When G.751 framing is used, DSU bandwidth can be used to select a payload subrate from 34010 kbps down to 22 kbps. Before framing bypass can be used, a DSU bandwidth of 34010 kbps must be configured.
Even though software allows the user to configure a continuous range of bandwidths in subrate modes, vendors support bandwidths only in quantums (for example, in an E3 digital link, bandwidth must be in multiples of 358 kbps). Therefore, the software sets the user-configured bandwidth to the closest vendor-supported bandwidth. Use the show interfaces serial slot/port command to display the actual bandwidth that is configured.
The user-configured subrate mode, subrate bandwidth, actual subrate bandwidth configured, and scramble configuration are displayed near the end of the show interfaces serial command output.
The following table shows DSU modes and vendor-supported bandwidths.
Examples
The following example sets the maximum allowable DSU bandwidth to 16,000 kbps on interface 1/0/0:
Router(config)# interface serial 1/0/0Router(config-if)# dsu bandwidth 16000The following example shows the user-configured subrate bandwidth and the actual configured subrate bandwidth as displayed in the output of the show interfaces serial command:
Router# show interfaces serialSerial1/0 is up, line protocol is upHardware is DSXPNM SerialMTU 1500 bytes, BW 44210 Kbit, DLY 20000 usec,reliability 253/255, txload 1/255, rxload 1/255Encapsulation HDLC, crc 16, loopback not setKeepalive not setDTR is pulsed for 0 seconds on reset, Restart-Delay is 1637167 secsLast input 04:59:04, output 04:59:04, output hang neverLast clearing of "show interface" counters 00:00:02Input queue:0/75/0/0 (size/max/drops/flushes); Total output drops:0Queueing strategy:fifoOutput queue :0/40 (size/max)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, 0 interface resets0 output buffer failures, 0 output buffers swapped out0 carrier transitionsDSU mode 0, bandwidth 34010, real bandwidth 34010, scramble 0Related Commands
show interfaces serial
Displays information that is specific to the interface hardware.
dsu mode
To specify the interoperability mode used by a T3 or E3 controller or the PA-T3 and PA-E3 port adapters, use the dsu mode command in interface configuration mode. To return to the default mode, use the no form of this command.
dsu mode {0 | 1 | 2 | 3 | 4}
no dsu mode
Syntax Description
Defaults
0
Command Modes
Interface configuration
Command History
Usage Guidelines
Scrambling Support on T3 and E3 Serial Interfaces in DSU Mode 1
DSU mode 1 refers to Kentrox mode. If DSU mode is used on a T3 serial interface and the bandwidth is = > 35,000 bps, the scrambling option is not supported. Likewise, if DSU mode 1 is used for an E3 serial interface and the bandwidth is = > 24,510 bps, scrambling is not supported.
Match Local and Remote DSU Configurations
The local interface configuration must match the remote interface configuration. For example, if you define the data service unit (DSU) interoperability mode as 1 on the local port, you must also do the same on the remote port.
Know the DSU Type
You must know what type of DSU is connected to the remote port to determine if it interoperates with an E3 or T3 controller or a PA-E3 or PA-T3 port adapter. The dsu mode command enables and improves interoperability with other DSUs.
Verify DSU Mode
To verify the DSU mode configured on the interface, use the show controllers serial or show interfaces serial EXEC commands.
Examples
The following example sets the DSU mode to 1 on interface 1/0/0:
Router(config)# interface serial 1/0/0Router(config-if)# dsu mode 1The following example shows the configuration for a serial interface configured in DSU mode 1. The bandwidth is set higher than that supported by the Kentrox firmware allows for scrambling. therefore, the scrambling option is not supported in this configuration.
Router(config)# interface serial 1/0/0Router(config-if)# mtu 4474Router(config-if)# ip address 216.186.93.114 255.255.255.252Router(config-if)# ip mtu 4470Router(config-if)# dsu mode 1Router(config-if)# dsu bandwidth 44210Related Commands
show controllers serial
Displays information that is specific to the serial controllers.
show interfaces serial
Displays information that is specific to the interface hardware.
dte-invert-txc
To invert the transmit external clock (TXC) signal received from the DCE when the device is operating as a DTE, use the dte-invert-txc command in interface configuration mode. If the DCE accepts serial clock transmit external (SCTE) signal when the device is operating as a DTE, use the no form of this command.
dte-invert-txc
no dte-invert-txc
Syntax Description
This command has no arguments or keywords.
Defaults
The TXC signal is not inverted.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command if the DCE cannot receive SCTE from the DTE, the data is running at high speeds, and the transmission line is long. The dte-invert-txc command prevents phase shifting of the data with respect to the clock.
On the Cisco 4000 series, you can specify the serial Network Processor Module timing signal configuration. When the board is operating as a DTE, the dte-invert-txc command inverts the TXC clock signal it gets from the DCE that the DTE uses to transmit data.
If the DCE accepts SCTE from the DTE, use no dte-invert-txc.
Examples
The following example inverts the TXC on serial interface 0:
Router(config)# interface serial 0Router(config-if)# dte-invert-txcduplex
To configure duplex operation on an interface, use the duplex command in interface configuration mode. To return the system to half-duplex mode, the system default, use the no form of this command.
duplex {full | half | auto}
no duplex
Syntax Description
Defaults
Half-duplex mode
Command Modes
Interface configuration
Command History
Usage Guidelines
To use the autonegotiation capability (that is, detect speed and duplex modes automatically), you must set both speed and duplex to auto.
Table 7 describes the access server's performance for different combinations of the duplex and speed modes. The specified duplex command configured with the specified speed command produces the resulting system action.
For the Cisco AS5300, the duplex {full | half | auto} command syntax replaces the following two earlier duplex commands:
•
•
You will get the following error messages if you try to use these commands on a Cisco AS5300:
Router(config)# interface fastethernet 0Router(config-if)# full-duplexPlease use duplex command to configure duplex modeRouter(config-if)#Router(config-if)# half-duplexPlease use duplex command to configure duplex modeExamples
The following example shows how to configure full- duplex operation on a Cisco AS5300:
Router(config)# interface fastethernet 0Router(config-if)# duplex fullRelated Commands
e2-clockrate
To configure serial interface 0 for E2 (8 MHz full duplex) and to shut down the other three serial interfaces (1 to 3), use the e2-clockrate command in interface configuration mode. To disable the full duplex E2, use the no form of this command.
e2-clockrate
no e2-clockrate
Syntax Description
This command has no arguments or keywords.
Defaults
All interfaces are running.
Command Modes
Interface configuration
Command History
12.0(2)XD
This command was introduced.
12.0(3)T
This command was integrated into Cisco IOS Release 12.0(3)T.
Usage Guidelines
The e2-clockrate command is an interface configuration command and is seen only with interface serial0. When this command is used, serial interface 0 supports speeds up to E2 (8 MHz full duplex) and the other three serial interfaces (1 to 3) are put in the "shutdown" state. Also, running this command displays the following warning message:
Serial interface 0 is configured to support E2 rates and serial ports "1-3" are moved to shutdown state.Examples
The following example shows sample display output for the e2-clockrate EXEC command.
Router(config-if)# e2-clockrateInterface Serial 0 is configured to support clockrates up to E2 (8Mbps)Interfaces serial 1-3 will not be operationalRelated Commands
clock rate
Configures the clock rate for the hardware connections on serial interfaces such as NIMs and interface processors to an acceptable bit rate.
early-token-release
To enable early token release on Token Ring interfaces, use the early-token-release command in interface configuration mode. To disable this function, use the no form of this command.
early-token-release
no early-token-release
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Early token release is a method whereby the Token Ring interfaces can release the token back onto the ring immediately after transmitting, rather than waiting for the frame to return. This feature helps increase the total bandwidth of the Token Ring.
The Token Ring Interface Processor (TRIP) on the Cisco 7500 series routers and the Token Ring adapters on the Cisco 7200 series routers all support early token release.
Examples
The following example enables the use of early token release on Token Ring interface 1:
Router(config)# interface tokenring 1Router(config-if)# early-token-releaseThe following example enables the use of early token release on the Token Ring interface processor in slot 4 on port 1 on the Cisco 7500 series routers:
Router(config)# interface tokenring 4/1Router(config-if)# early-token-releaseencapsulation
To set the encapsulation method used by the interface, use the encapsulation command in interface configuration mode. To remove the encapsulation, use the no form of this command.
encapsulation encapsulation-type
no encapsulation encapsulation-type
Syntax Description
Defaults
The default depends on the type of interface. For example, synchronous serial interfaces default to HDLC and asynchronous interfaces default to SLIP.
Command Modes
Interface configuration
Command History
Usage Guidelines
SLIP and PPP
To use SLIP or PPP, the router or access server must be configured with an IP routing protocol or with the ip host-routing command. This configuration is done automatically if you are using old-style slip address commands. However, you must configure it manually if you configure SLIP or PPP via the interface async command.
On lines configured for interactive use, encapsulation is selected by the user when they establish a connection with the slip or ppp EXEC command.
IP Control Protocol (IPCP) is the part of PPP that brings up and configures IP links. After devices at both ends of a connection communicate and bring up PPP, they bring up the control protocol for each network protocol that they intend to run over the PPP link such as IP or IPX. If you have problems passing IP packets and the show interface command shows that line is up, use the negotiations command to see if and where the negotiations are failing. You might have different versions of software running, or different versions of PPP, in which case you might need to upgrade your software or turn off PPP option negotiations. All IPCP options as listed in RFC 1332, PPP Internet Protocol Control Protocol (IPCP), are supported on asynchronous lines. Only Option 2, TCP/IP header compression, is supported on synchronous interfaces.
PPP echo requests are used as keepalive packets to detect line failure. The no keepalive command can be used to disable echo requests. For more information about the no keepalive command, refer to the chapter "IP Services Commands" in the Cisco IOS IP Command Reference, Volume 1 of 4: Addressing and Services and to the chapter "Configuring IP Services" in the Cisco IOS IP Configuration Guide.
To use SLIP or PPP, the Cisco IOS software must be configured with an IP routing protocol or with the ip host-routing command. This configuration is done automatically if you are using old-style slip address commands. However, you must configure it manually if you configure SLIP or PPP via the interface async command.
Note
SS7
The SS7 encapsulation command is new with the Integrated SLT feature and is available only for interface serial objects created by the channel-group command. For network access server (NAS) platforms, the encapsulation for channel group serial interface objects defaults to HDLC. You must explicitly set the encapsulation type to SS7 to override this default.
When encapsulation is set to SS7, the encapsulation command for that object is no longer available. A serial SS7 link is deleted only when its associated dial feature card (DFC) card is removed. As with existing Cisco 26xx-based SLTs, you do not need to specify whether the SS7 link is to be used as an A-link or an F-link.
By itself this command does not select the correct encapsulation type. Therefore, once created, you must set the encapsulation type to the new SS7 value, as well as assign a session channel ID to the link at the serial interface command level. The configuration on a digital SS7 link can be saved (no shutdown) only when its encapsulation is successfully set to SS7 and it has been assigned a channel identifier.
VLANs
Do not configure encapsulation on the native VLAN of an IEEE 802.1q trunk without the native keyword. (Always use the native keyword when the vlan-id is the ID of the IEEE 802.1q native VLAN.)
For detailed information on use of this command with VLANs, refer to the Cisco IOS Switching Services Configuration Guide and the Cisco IOS Switching Services Command Reference.
Examples
The following example shows how to reset HDLC serial encapsulation on serial interface 1:
Router(config)# interface serial 1Router(config-if)# encapsulation hdlcThe following example shows how to enable PPP encapsulation on serial interface 0:
Router(config)# interface serial 0Router(config-if)# encapsulation pppThe following example shows how to configure async interface 1 for PPP encapsulation:
Router(config)# interface async 1Router(config-if)# encapsulation pppTo learn more about the virtual serial interface and check SS7 encapsulation, enter the show interfaces serial slot/trunk:channel-group command in privileged EXEC mode, as in the following example:
Router# show interfaces serial 7/3:1Serial7/3:1 is up, line protocol is downHardware is PowerQUICC SerialMTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,reliability 255/255, txload 4/255, rxload 1/255Encapsulation SS7 MTP2, loopback not setKeepalive set (10 sec)Last input never, output 00:00:00, output hang neverLast clearing of "show interface" counters 03:53:40Queueing strategy: fifoOutput queue 0/40, 0 drops; input queue 0/75, 0 drops5 minute input rate 0 bits/sec, 0 packets/sec5 minute output rate 26000 bits/sec, 836 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 abort11580159 packets output, 46320636 bytes, 0 underruns0 output errors, 0 collisions, 1 interface resets0 output buffer failures, 0 output buffers swapped out2 carrier transitionsDCD=up DSR=down DTR=down RTS=down CTS=downRelated Commands
end (satellite initial configuration)
To exit satellite initial configuration mode, save any new or changed parameters, and reset the Cisco IP VSAT satellite WAN network module (NM-1VSAT-GILAT), use the end command in satellite initial configuration mode.
end
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values
Command Modes
Satellite initial configuration
Command History
Usage Guidelines
The end command is identical to the exit command in satellite initial configuration mode.
When you enter the exit or end command to exit satellite initial configuration mode, the system automatically saves any changed parameters to the NM-1VSAT-GILAT network module nonvolatile memory and resets the NM-1VSAT-GILAT network module.
Examples
The following example shows what appears when you enter the end or exit command after changing one or more initial configuration parameters:
Router(sat-init-config)# endApplying changed parameters to the satellite module.Parameter update succeeded. Module is now resetting.Router#The following example shows what appears when you enter the end or exit command when no parameters have been changed:
Router(sat-init-config)# endRouter#Related Commands
exit (satellite initial configuration)
To exit satellite initial configuration mode, save any new or changed parameters, and reset the Cisco IP VSAT satellite WAN network module (NM-1VSAT-GILAT), use the exit command in satellite initial configuration mode.
exit
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values
Command Modes
Satellite initial configuration
Command History
Usage Guidelines
The exit command is identical to the end command in satellite initial configuration mode.
When you enter the exit or end command to exit satellite initial configuration mode, the system automatically saves any changed parameters to the NM-1VSAT-GILAT network module nonvolatile memory and resets the NM-1VSAT-GILAT network module.
Examples
The following example shows what appears when you enter the exit or end command after changing one or more initial configuration parameters:
Router(sat-init-config)# exitApplying changed parameters to the satellite module.Parameter update succeeded. Module is now resetting.Router#The following example shows what appears when you enter the exit or end command when no parameters have been changed:
Router(sat-init-config)# exitRouter#Related Commands
error throttling
To stop receiving error data packets on multiple channel groups configured on all interfaces on the T1 controller of a channelized T3 port adapter, use the error throttling command in T3 controller configuration mode. To continue receiving error data packets on all channels on the T1 controller, use the no form of this command.
error throttling
no error throttling
Syntax Description
This command has no arguments or keywords.
Defaults
The error throttling command is enabled by default.
Command Modes
T3 controller configuration
Command History
Usage Guidelines
Use the show controllers t3 command to display whether the current router configuration has error throttling enabled or disabled.
The error throttling command disables the T1 level clock in order to stop receiving error data packets on a T1 controller.
When a T1 has multiple channel groups configured over it, error throttling affects all the channels on a T1. If any single interface receives a burst of errors, over a short duration, such as 400 errors in 100 milliseconds, the T1 clock is turned off for a period of 100 milliseconds. The reason is that when there is a high rate of errors, the error rate is very likely to continue for a long duration of time. Using error throttling to stop receiving the error data packets reduces wasteful processing and discarding of error packets.
The no error throttling command allows all the error data packets to be processed, dropped, and accounted for on a T1 controller. When the error rate is high, the CPU can become overloaded.
When the no error throttling command is used to configure a T3 port, the configuration applies to all of the 28 associated T1 channels.
Examples
The following example enables error throttling by disabling the T1 clock in order to stop receiving error data packets on a T1 controller:
Router(config-controller)# error throttlingThe following example uses the show controllers t3 command to display partial output showing that error throttling is enabled on the T1 controller:
Router# show controllers t3 2/1/0T3 2/1/0 is down. Hardware is 2CT3 single wide port adapterCT3 H/W Version: 0.2.2, CT3 ROM Version: 1.0, CT3 F/W Version: 2.5.1FREEDM version: 1, reset 0 resurrect 0Applique type is Channelized T3Transmitter is sending remote alarm.Receiver has loss of signal.FEAC code received: No code is being receivedFraming is M23, Line Code is B3ZS, Clock Source is InternalRx-error throttling on T1's ENABLED...Related Commands
show controllers t3
Displays whether the current router configuration has error throttling enabled or disabled.
fddi burst-count
To allow the FCI card to preallocate buffers to handle bursty FDDI traffic (for example, Network File System [NFS] bursty traffic), use the fddi burst-count command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi burst-count number
no fddi burst-count
Syntax Description
Defaults
3 buffers
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to the FCI card only.
Note
Examples
The following example sets the number of buffers to 5:
Router(config)# interface fddi 0Router(config-if)# fddi burst-count 5fddi c-min
To set the C-Min timer on the pulse code modulation (PCM), use the fddi c-min command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi c-min microseconds
no fddi c-min
Syntax Description
Defaults
1600 microseconds
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to the processor connection management (CMT) only. You need extensive knowledge of the PCM state machine to tune this timer. Use this command when you run into PCM interoperability problems.
Examples
The following example sets the C-Min timer to 2000 microseconds:
Router(config)# interface fddi 0Router(config-if)# fddi c-min 2000Related Commands
fddi cmt-signal-bits
To control the information transmitted during the connection management (CMT) signaling phase, use the fddi cmt-signal-bits command in interface configuration mode.
fddi cmt-signal-bits signal-bits [phy-a | phy-b]
Syntax Description
signal-bits
A hexadecimal number preceded by 0x; for example, 0x208. The FDDI standard defines 10 bits of signaling information that must be transmitted, as follows:
•
•
•
•
•
•
•
•
phy-a
(Optional) Selects Physical Sublayer A. The default is 0x008 (hexadecimal) or 00 0000 1000 (binary). Bits 1 and 2 are set to 00 to select Physical A. Bit 3 is set to 1 to indicate "accept any connection."
phy-b
(Optional) Selects Physical Sublayer B. The default is 0x20c (hexadecimal) or 10 0000 1100 (binary). Bits 1 and 2 are set to 10 to select Physical B. Bit 3 is set to 1 to indicate "accept any connection." Bit 9 is set to 1 to select MAC on output. The normal data flow on FDDI is input on Physical A and output on Physical B.
Defaults
•
•
Command Modes
Interface configuration
Command History
Usage Guidelines
If neither the phy-a nor phy-b keyword is specified, the signal bits apply to both physical connections.
Caution
Table 8 lists the physical types.
Table 8 FDDI Physical Type Bit Specifications
0
0
Physical A
1
0
Physical B
0
1
Physical S
1
1
Physical M
Table 9 lists the duration bits.
This command does not have a no form.
Examples
The following example sets the CMT signaling phase to signal bits 0x208 on both physical connections:
Router(config)# interface fddi 0Router(config-if)# fddi cmt-signal-bits 0x208fddi duplicate-address-check
To enable the duplicate address detection capability on the FDDI interface, use the fddi duplicate-address-check command in interface configuration mode. To disable this function, use the no form of this command.
fddi duplicate-address-check
no fddi duplicate-address-check
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
If you use this command, the Cisco IOS software will detect a duplicate address if multiple stations are sharing the same MAC address. If the software finds a duplicate address, it will shut down the interface.
Examples
The following example enables duplicate address checking on the FDDI interface:
Router(config)# interface fddi 0Router(config-if)# fddi duplicate-address-checkfddi encapsulate
To specify encapsulating bridge mode on the CSC-C2/FCIT interface card, use the fddi encapsulate command in interface configuration mode. To turn off encapsulation bridging and return the FCIT interface to its translational, nonencapsulating mode, use the no form of this command.
fddi encapsulate
no fddi encapsulate
Syntax Description
This command has no arguments or keywords.
Defaults
By default, the FDDI interface uses the SNAP encapsulation format defined in RFC 1042, Standard for the Transmission of IP Datagrams Over IEEE 802 Networks. It is not necessary to define an encapsulation method for this interface when using the CSC-FCI interface card.
Command Modes
Interface configuration
Command History
Usage Guidelines
The no fddi encapsulate command applies only to CSC-C2/FCIT interfaces, because the CSC-FCI interfaces are always in encapsulating bridge mode. The CSC-C2/FCIT interface card fully supports transparent and translational bridging for the following configurations:
•
•
•
The fddi encapsulate command puts the CSC-C2/FCIT interface into encapsulation mode when doing bridging. In transparent mode, the FCIT interface interoperates with earlier versions of the CSC-FCI encapsulating interfaces when performing bridging functions on the same ring.
Caution
from occurring. These problems include bit-order translation (or usage of MAC addresses as data), maximum transfer unit (MTU) differences, frame status differences, and multicast address usage.
Some or all of these problems might be present in a multimedia bridged LAN and might prevent communication from taking place. These problems are most prevalent when bridging between
Token Rings and Ethernets or between Token Rings and FDDI nets. This is because of the different
way Token Ring is implemented by the end nodes.
The following protocols have problems when bridged between Token Ring and other media: Novell IPX, DECnet Phase IV, AppleTalk, VINES, XNS, and IP. Furthermore, the following protocols may have problems when bridged between FDDI and other media: Novell IPX and XNS. We recommend that these protocols be routed whenever possible.
Examples
The following example sets FDDI interface 1 on the CSC-C2/FCIT interface card to encapsulating bridge mode:
Router(config)# interface fddi 1Router(config-if)# fddi encapsulatefddi frames-per-token
To specify the maximum number of frames that the FDDI interface transmits per token capture, use the fddi frames-per-token command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi frames-per-token number
no fddi frames-per-token
Syntax Description
number
Maximum number of frames to transmit per token capture. Valid values are from 1 to 10. The default is 3.
Defaults
3 frames
Command Modes
Interface configuration
Command History
Usage Guidelines
Changing the value will increase or decrease the maximum number of frames that the FDDI interface can transmit when it receives a token. Increasing the value does not necessarily mean more frames will be transmitted on each token capture. This is heavily dependent on the traffic load of the specific interface.
When the interface captures a token, it transmits all of the frames that are queued in the interface's transmit ring, up to a maximum value specified by the fddi frames-per-token command.
If there are no frames ready for transmission, the token is passed on, and no frames are transmitted. If there are less than the fddi frames-per-token value in the transmit ring, all frames in the transmit ring are transmitted before the token is passed on. If there are more than the fddi frames-per-token value in the transmit ring, the specified value is transmitted before the token is passed on. The remaining frames in the transmit ring remain queued until the token is captured again.
Examples
The following example shows how to configure the FDDI interface to transmit four frames per token capture:
Router(config-if)# fddi frames-per-token 4fddi smt-frames
To enable the Station Management (SMT) frame processing capability on the FDDI, use the fddi smt-frames command in interface configuration mode. To disable this function and prevent the Cisco IOS software from generating or responding to SMT frames, use the no form of this command.
fddi smt-frames
no fddi smt-frames
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the no form of this command to turn off SMT frame processing for diagnosing purposes. Use the fddi smt-frames command to reenable the feature.
Examples
The following example disables SMT frame processing:
Router(config)# interface fddi 0Router(config-if)# no fddi smt-framesfddi tb-min
To set the TB-Min timer in the physical connection management (PCM), use the fddi tb-min command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi tb-min milliseconds
no fddi tb-min
Syntax Description
milliseconds
Number, in milliseconds, that sets the TB-Min timer value. The range is from 0 to 65535. The default is 100.
Defaults
milliseconds: 100
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to the processor connection management (CMT) only. Use this command when you run into PCM interoperability problems.
Note
Examples
The following example shows how to set the TB-Min timer to 200 ms:
Router(config)# interface fddi 0Router(config-if)# fddi tb-min 200Related Commands
fddi tl-min-time
To control the TL-Min time (the minimum time to transmit a Physical Sublayer, or PHY line state, before advancing to the next physical connection management [PCM] state, as defined by the X3T9.5 specification), use the fddi tl-min-time command in interface configuration mode.
fddi tl-min-time microseconds
Syntax Description
Defaults
microseconds: 30
Command Modes
Interface configuration
Command History
Usage Guidelines
Interoperability tests have shown that some implementations of the FDDI standard need more than 30 microseconds to sense a signal.
This command does not have a no form.
Examples
The following example changes the TL-Min time from 30 microseconds to 100 microseconds:
Router(config)# interface fddi 0Router(config-if)# fddi tl-min-time 100The following example changes the TL-Min time from 30 microseconds to 100 microseconds on a Cisco 7500 series router:
Router(config)# interface fddi 3/0Router(config-if)# fddi tl-min-time 100Related Commands
fddi token-rotation-time
To control ring scheduling during normal operation and to detect and recover from serious ring error situations, use the fddi token-rotation-time command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi token-rotation-time microseconds
no fddi token-rotation-time
Syntax Description
microseconds
Number, in microseconds, that specifies the token rotation time (TRT). The range is from 4000 to 165000. The default is 5000.
Defaults
microseconds: 5000
Command Modes
Interface configuration
Command History
Usage Guidelines
The FDDI standard restricts the allowed time to be greater than 4000 microseconds and less than 165,000 microseconds. As defined in the X3T9.5 specification, the value remaining in the TRT is loaded into the token holding timer (THT). Combining the values of these two timers provides the means to determine the amount of bandwidth available for subsequent transmissions.
Examples
The following example sets the rotation time to 24,000 microseconds:
Router(config)# interface fddi 0Router(config-if)# fddi token-rotation-time 24000The following example sets the rotation time to 24,000 microseconds on a Cisco 7500 series router:
Router(config)# interface fddi 3/0Router(config-if)# fddi token-rotation-time 24000fddi t-out
To set the timeout timer in the physical connection management (PCM), use the fddi t-out command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi t-out milliseconds
no fddi t-out
Syntax Description
milliseconds
Number, in milliseconds, that sets the timeout timer. The range is from 0 to 65535. The default is 100.
Defaults
milliseconds: 100
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to the processor connection management (CMT) only. Use this command when you run into PCM interoperability problems.
Note
Examples
The following example sets the timeout timer to 200 ms:
Router(config)# interface fddi 0Router(config-if)# fddi t-out 200Related Commands
fddi valid-transmission-time
To change the transmission valid timer (TVX) interval, use the fddi valid-transmission-time command in interface configuration mode. To revert to the default value, use the no form of this command.
fddi valid-transmission-time microseconds
no fddi valid-transmission-time
Syntax Description
microseconds
Number, in microseconds, that specifies the TVX interval. The range is from 2500 to 2147483647. The default is 2500.
Defaults
microseconds: 2500
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to recover from a transient FDDI ring error by setting a longer transmission timer interval.
Examples
The following example shows how to change the transmission timer interval to 3000 microseconds:
Router(config)# interface fddi 0Router(config-if)# fddi valid-transmission-time 3000The following example shows how to change the transmission timer interval to 3000 microseconds on Cisco 7000 series routers or Cisco 7200 series routers:
Router(config)# interface fddi 3/0Router(config-if)# fddi valid-transmission-time 3000fdl
To set the Facility Data Link (FDL) exchange standard for CSU controllers or to set the FDL exchange standard for a T1 interface that uses the Extended Super Frame (ESF) framing format, use the fdl command in ATM interface configuration mode. To disable FDL support or to specify that there is no ESF FDL, use the no form of this command.
fdl {att | ansi | all | none}
no fdl {att | ansi | all | none}
Syntax Description
Defaults
ansi
Command Modes
ATM interface configuration
Command History
Usage Guidelines
This command is available for T1 links only and sets the standard that will be followed for FDL messaging through a 4-Kbps out-of-band channel that a service provider uses to check for errors on the facility. You must use the same FDL exchange standard as your service provider. If the setting is not correct, the link may fail to come up. You can have a different standard configured on each T1 interface.
Note
router, ESF framing and binary eight zero substitution (B8ZS) line encoding are supported. When
using a multiport E1 ATM IMA network module on a Cisco 2600 or Cisco 3600 series router,
CRC4 multiframe framing and HDB3 line encoding are supported. These are the parameters
specified by the ATM Forum, and they cannot be changed.Examples
The following example shows how to specify both ANSI and AT&T standards for FDL exchange on a Cisco 2600 or Cisco 3600 series router:
Router(config)# interface atm 0/2Router(config-if)# fdl allframing
To select the frame type for the T1 or E1 data line, use the framing command in controller configuration mode.
T1 Lines
framing {sfadm | esfadm}
E1 Lines
framing {crc4adm | pcm30adm | clear e1}
Syntax Description
Defaults
Extended super frame for a T1 line
CRC4 disabled framing for an E1 lineCommand Modes
Controller configuration
Command History
Usage Guidelines
Use this command in configurations in which the router or access server is intended to communicate with T1 or E1 fractional data lines. The service provided determines which framing type is required for your T1 or E1 circuit.
This command does not have a no form.
Examples
The following example selects extended super frame as the T1 frame type:
Router(config)# controller t1 4/0Router(config-controller)# framing esfadmRelated Commands
lbo
Specifies the distance of the cable from the routers to the network equipment.
linecode
Selects the line code type for a T1 or E1 line.
framing (CEM)
To specify the framing format of a circuit emulation (CEM) T1 or E1 port, use the framing command in controller configuration mode. To reset the framing format of the port to its default value, use the no form of this command.
T1 Port
framing {sf | esf | unframed}
no framing
E1 Port
framing {crc4 | no-crc4 | unframed}
no framing
Syntax Description
Defaults
T1 lines default to esf.
E1 lines default to crc4.
The unframed option is automatically selected if an unframed CEM channel is created on the port using the cem-group command.Command Modes
Controller configuration
Command History
Usage Guidelines
Framing must be configured to match the framing format used by the attached equipment.
In order to change a line between unframed and any framed mode, you must first delete the CEM channels defined in the line.
Examples
The following example shows how to set the framing format of a CEM T1 port to be super frame format.
Router(config-controller)# framing sfThe following example shows how to set the framing format of a CEM E1 port to the G.704 standard with the optional CRC4 mechanism defined in time slot 0 disabled.
Router(config-controller)# framing no-crc4Related Commands
framing (E3 controller)
To specify the type of framing used by the E3 controller, use the framing command in controller configuration mode. To restore the default framing type, use the no form of this command.
framing {bypass | g751}
no framing
Syntax Description
bypass
Specifies that G.751 framing be bypassed.
g751
Specifies G.751 as the E3 framing type. This is the default.
Defaults
G.751 framing
Command Modes
Controller configuration
Command History
Usage Guidelines
If you do not specify the framing command, the default, g751, is used by the E3 controller to automatically determine the framing type received from the far-end equipment.
Configure framing as G.751 when the E3 connection terminates remotely on a Digital Link or Kentrox data service unit (DSU), or when needing a subrate on an E3 connection between two T3 or E3 network modules.
Note
When G.751 framing is used, DSU bandwidth can be used to select a payload subrate from 34,010 kbps down to 22 kbps.
When framing bypass is used, DSU bandwidth of 34,010 kbps must be configured.
When G.751 framing is used, configuring the scramble command can prevent some payload data from being mistakenly interpreted as G.751 framing bits by switches placed between the DSUs. By default, the no scramble command is configured.
When framing bypass is used, the no scramble command must be configured.
When G.751 framing is used, bit 11 of the G.751 frame is reserved for national use and is set to 1 by default.
Configure national bit 1 only when required for interoperability with your telephone company.
Examples
The following example shows the framing for the E3 controller set to bypass:
Router(config)# controller e3 1/0Router(config-controller)# framing bypassRelated Commands
scramble
Specifies the type of framing used by the T1 channels on the CT3IP in Cisco 7500 series routers.
framing (SONET)
To select the frame type of the frame received on an optical line, use the framing command in controller configuration mode.
framing {sonet | sdh}
Syntax Description
Defaults
SONET is the default for the PA-MC-STM-1 port adapter.
SDH is the default for the STM-1 trunk card.Command Modes
Controller configuration
Command History
Usage Guidelines
Use this command to configure the framing type of the SONET controller. The PA-MC-STM-1port adapter supports both the SONET and SDH framing modes. The STM-1 trunk feature card on the Cisco AS5850 only supports SDH framing.
This command does not have a no form.
Examples
The following example shows how to configure the framing type on a SONET controller of an STM-1 card in physical slot number 2 on a Cisco AS5850:
Router(config)# controller sonet 2/0Router(config-controller)# framing sdhRelated Commands
framing (T1/E1 controller)
To select the frame type for the T1 or E1 data line, use the framing command in controller configuration mode.
T1 Lines
framing {sf | esf}
E1 Lines
framing {crc4 | no-crc4} [australia]
Syntax Description
Defaults
Super frame is the default on a T1 line.
CRC4 frame is the default on an E1 line.Command Modes
Controller configuration
Usage Guidelines
Use this command in configurations in which the router or access server is intended to communicate with T1 or E1 fractional data lines. The service provider determines the framing type required for your T1/E1 circuit.
This command does not have a no form.
Examples
The following example selects extended super frame as the T1 frame type:
Router(config-controller)# framing esfRelated Commands
cablelength
Specifies the distance of the cable from the routers to the network equipment.
linecode
Selects the linecode type for T1 or E1 line.
framing (T3 controller)
To specify the type of framing used by the T3 controller or by the CT3IP port adapter in Cisco 7500 series routers, use the framing command in controller configuration mode. To restore the default framing type, use the no form of this command.
T3 Controllers
framing {c-bit | m23}
no framing
Cisco 7500 Series Routers with CT3IP Port Adapter
framing {c-bit | m23 | auto-detect}
no framing
Syntax Description
Defaults
c-bit for most T3 controllers
auto-detect for the CT3IP in a Cisco 7500 series routerCommand Modes
Controller configuration
Command History
Usage Guidelines
If you do not specify the framing command, the default c-bit is used by most T3 controllers to automatically determine the framing type received from the far-end equipment. If you do not specify the framing command on the CT3IP, the default auto-detect is used to automatically determine the framing type received from the far-end equipment.
Because the CT3IP supports the Application Identification Channel (AIC) signal, the setting for the framing might be overridden by the CT3IP firmware.
You can also set the framing for each T1 channel by using the t1 framing controller configuration command.
Examples
The following example sets the framing for the CT3IP to C-bit:
Router(config)# controller t3 9/0/0Router(config-controller)# framing c-bitRelated Commands
t1 framing
Specifies the type of framing used by the T1 channels on the CT3IP in Cisco 7500 series routers.
framing (T3/E3 interface)
To specify T3 or E3 line framing for a PA-T3 or PA-E3 port adapter, use the framing command in interface configuration mode. To return to the default C-bit framing or G.751 framing, use the no form of this command.
PA-T3
framing {c-bit | m13 | bypass}
no framing
PA-E3
framing {bypass | g751}
no framing
Syntax Description
Defaults
C-bit framing for PA-T3
G.751 framing for PA-E3Command Modes
Interface configuration
Command History
Usage Guidelines
The default framing is described in the ITU-T Recommendation G.751.
Note
When the framing mode is bypass, the T3 frame data is not included in the T3 frame, just the data.
When the framing mode is bypass, the E3 frame data is not included in the E3 frame, just the data.
If you use the bypass keyword, scrambling must be set to the default (disabled), the DSU mode must be set to the default (0), and the DSU bandwidth must be set to the default (44736).
To verify the framing mode configured on the interface, use the show controllers serial command in EXEC mode.
Examples
The following example sets the framing mode to bypass on interface 1/0/0:
Router(config)# interface serial 1/0/0Router(config-if)# framing bypassRelated Commands
show controllers serial
Displays information that is specific to the interface hardware.
full-duplex
To specify full-duplex mode on full-duplex single-mode and multimode port adapters, use the full-duplex command in interface configuration mode. To restore the default half-duplex mode, use the no form of this command.
full-duplex
no full-duplex
Syntax Description
This command has no arguments or keywords.
Defaults
Half-duplex mode is the default mode on a Cisco 7500 series router, a Fast Ethernet Interface Processor (FEIP), and serial interfaces that are configured for bisynchronous tunneling.
Command Modes
Interface configuration
Command History
11.1
This command was introduced.
11.3
This command was modified to include information on FDDI full-duplex, single-mode, and multimode port adapters.
Usage Guidelines
Use this command if the equipment on the other end is capable of full-duplex mode.
This command specifies full-duplex mode on full-duplex single-mode and multimode port adapters available on the following networking devices:
•
•
•
•
Refer to the Cisco Product Catalog for hardware compatibility information and for specific model numbers of port adapters.
To enable half-duplex mode, use the no full-duplex or half-duplex commands.
Note
and half-duplex commands on a Cisco AS5300:
Router(config)# interface fastethernet 0
Router(config-if)# full-duplex
Please use duplex command to configure duplex mode
Router(config-if)#
Router(config-if)# half-duplex
Please use duplex command to configure duplex modeSupport for This Command
Use the question mark (?) command to find out which port adapters support this command. If the interface does not support full-duplex, an informational message similar to the one shown below is displayed, and no changes are made to the interface. To determine if the interface supports full-duplex, use the show interfaces command. For example, the following message is displayed if the interface does not support full-duplex:
% interface does not support full-duplex.Use on FDDI
Full-duplex on the FDDI full-duplex port adapters allows an FDDI ring with exactly two stations to transform the ring into a full-duplex, point-to-point topology. To operate in full-duplex mode, there must be only two stations on the ring, the two stations must be capable of operating in full-duplex mode, and both stations must complete a full-duplex autoconfiguration protocol. There is no FDDI token in full-duplex mode. Refer to the Cisco Product Catalog for specific model numbers of port adapters.
Full-duplex autoconfiguration protocol allows an FDDI station to dynamically and automatically operate in either half-duplex (or ring) or full-duplex mode, and ensures that the stations fall back to ring mode when a configuration change occurs, such as a third station joining the ring.
After booting up, the FDDI stations begin operation in half-duplex mode. While the station performs the full-duplex autoconfiguration protocol, the station continues to provide data-link services to its users. Under normal conditions, the transition between half-duplex mode and full-duplex mode is transparent to the data-link users. The data-link services provided by full-duplex mode are functionally the same as the services provided by half-duplex mode.
If you change the full-duplex configuration (for example from disabled to enabled) on supported interfaces, the interface resets.
Examples
The following example configures full-duplex mode on the Cisco 7200 series routers:
Router(config)# interface fastethernet 0/1Router(config-if)# full-duplexThe following example specifies full-duplex binary synchronous communications (Bisync) mode:
Router(config)# interface serial 0Router(config-if)# encapsulation bstunRouter(config-if)# full-duplexThe following example enables full-duplex mode on FDDI interface 0:
Router(config)# interface fddi 0/1/0Router(config-if)# full-duplexRelated Commands
half-duplex
To specify half-duplex mode on an Synchronous Data Link Control (SDLC) interface or on the FDDI full-duplex, single-mode port adapter and FDDI full-duplex, multimode port adapter on the Cisco 7200 series and Cisco 7500 series routers, use the half-duplex command in interface configuration mode. To reset the interface to full-duplex mode, use the no form of this command.
half-duplex
no half-duplex
Syntax Description
This command has no arguments or keywords.
Defaults
Full-duplex mode is the default mode on an SDLC interface, the FDDI full-duplex, single-mode port adapter and FDDI full-duplex, multimode port adapter on the Cisco 7200 series and Cisco 7500 series routers.
Command Modes
Interface configuration
Command History
11.1
This command was introduced.
11.3
This command was modified to include information on FDDI full-duplex, single-mode, and multimode port adapters.
Usage Guidelines
SDLC Interfaces
The half-duplex command is used to configure an SDLC interface for half-duplex mode and is used on a variety of port adapters. Use the question mark (?) command to find out which port adapters support this command.
Note
Note
and half-duplex commands on a Cisco AS5300:
Router(config)# interface fastethernet 0
Router(config-if)# full-duplex
Please use duplex command to configure duplex mode
Router(config-if)#
Router(config-if)# half-duplex
Please use duplex command to configure duplex modeEnabling Full-Duplex Mode
To enable full-duplex mode, use the no half-duplex or full-duplex commands.
Note
the keyword half-duplex was removed from the media-type command. In Release 11.0(6), the functionality for specifying half-duplex mode is provided by the half-duplex command.Port Adapters
Refer to the Cisco Product Catalog for specific model numbers of port adapters.
Examples
The following example configures an SDLC interface for half-duplex mode:
Router(config-if)# encapsulation sdlc-primaryRouter(config-if)# half-duplexRelated Commands
Specifies full-duplex mode on full-duplex single-mode and multimode port adapters.
half-duplex controlled-carrier
To place a low-speed serial interface in controlled-carrier mode, instead of constant-carrier mode, use the half-duplex controlled-carrier command in interface configuration mode. To return the interface to constant-carrier mode, use the no form of this command.
half-duplex controlled-carrier
no half-duplex controlled-carrier
Syntax Description
This command has no arguments or keywords.
Defaults
Constant-carrier mode, where Data Carrier Detect (DCD) is held constant and asserted by the DCE half-duplex interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies only to low-speed serial DCE interfaces in half-duplex mode. Configure a serial interface for half-duplex mode by using the half-duplex command. Refer to the Cisco Product Catalog for specific model numbers of networking devices which support serial interfaces.
Controlled-carrier operation means that the DCE interface has DCD deasserted in the quiescent state. When the interface has something to transmit, it asserts DCD, waits a user-configured amount of time, then starts the transmission. When the interface has finished transmitting, it waits a user-configured amount of time and then deasserts DCD.
Examples
The following examples place the interface in controlled-carrier mode and then back into constant-carrier operation.
This example shows changing to controlled-carrier mode from the default of constant-carrier operation:
Router(config)# interface serial 2Router(config-if)# half-duplex controlled-carrierThis example shows changing to constant-carrier operation from controlled-carrier mode:
Router(config)# interface serial 2Router(config-if)# no half-duplex controlled-carrierRelated Commands
half-duplex timer
To tune half-duplex timers, use the half-duplex timer command in interface configuration mode. To return to the default parameter values, use the no form of this command.
half-duplex timer {cts-delay value | cts-drop-timeout value | dcd-drop-delay value | dcd-txstart-delay value | rts-drop-delay value | rts-timeout value | transmit-delay value}
no half-duplex timer {cts-delay value | cts-drop-timeout value | dcd-drop-delay value | dcd-txstart-delay value | rts-drop-delay value | rts-timeout value | transmit-delay value}
Syntax Description
Defaults
The default cts-delay value is 0 ms.
The default cts-drop-timeout value is 250 ms.
The default dcd-drop-delay value is 100 ms.
The default dcd-txstart-delay value is 100 ms.
The default rts-drop-delay value is 3 ms.
The default rts-timeout value is 3 ms.
The default transmit-delay value is 0 ms.Command Modes
Interface configuration
Command History
Usage Guidelines
Tuning Half-Duplex Timers
The half-duplex timer command is used to tune half-duplex timers. With these timer tuning commands you can adjust the timing of the half-duplex state machines to suit the particular needs of their half-duplex installation.
You can configure more than one option using this command, but each option must be specified as a separate command.
Note
Value Ranges
The range of values for the cts-delay and rts-timeout keywords are dependent on the serial interface hardware.
Examples
The following example set the cts-delay timer to 10 ms and the transmit-delay timer to 50 ms:
Router(config)# interface serial 2Router(config-if)# half-duplex timer cts-delay 10Router(config-if)# half-duplex timer transmit-delay 50Related Commands
hold-queue
To limit the size of the IP output queue on an interface, use the hold-queue command in interface configuration mode. To restore the default values, use the no form of this command.
hold-queue length {in | out}
no hold-queue {in | out}
Syntax Description
Defaults
The default input hold-queue limit is 75 packets.
The default output hold-queue limit is 40 packets.
For asynchronous interfaces the default is 10 packets.
These limits prevent a malfunctioning interface from consuming an excessive amount of memory. There is no fixed upper limit to a queue size.Command Modes
Interface configuration
Command History
Usage Guidelines
Back-to-Back Routing Updates
The default of 10 packets allows the Cisco IOS software to queue a number of back-to-back routing updates. This is the default for asynchronous interfaces only; other media types have different defaults.
Hold Queues and Priority Queueing
The hold queue stores packets received from the network that are waiting to be sent to the client. It is recommended that the queue size not exceed ten packets on asynchronous interfaces. For most other interfaces, queue length should not exceed 100.
The input hold queue prevents a single interface from flooding the network server with too many input packets. Further input packets are discarded if the interface has too many input packets outstanding in the system.
If priority output queueing is being used, the length of the four output queues is set using the priority-list global configuration command. The hold-queue command cannot be used to set an output hold queue length in this situation.
For slow links, use a small output hold-queue limit. This approach prevents storing packets at a rate that exceeds the transmission capability of the link. For fast links, use a large output hold-queue limit. A fast link may be busy for a short time (and thus require the hold queue), but can empty the output hold queue quickly when capacity returns.
To display the current hold queue setting and the number of packets discarded because of hold queue overflows, use the show interfaces command in EXEC mode.
Caution
This is generally better than having duplicate copies of the same packet within the network (which
can happen with large hold queues).
Examples
The following example shows how to set a small input queue on a slow serial line:
Router(config)# interface serial 0Router(config-if)# hold-queue 30 inRelated Commands
hssi external-loop-request
To allow the router to support a CSU/DSU that uses the loopback circuit (LC) signal to request a loopback from the router, use the hssi external-loop-request command in interface configuration mode. To disable this function, use the no form of this command.
hssi external-loop-request
no hssi external-loop-request
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
The HSA applique on the High-Speed Serial Interface (HSSI) contains an LED that indicates the loopback circuit A (LA), loopback circuit B (LB), and LC signals that are transiting through the devices. The CSU/DSU uses the LC signal to request a loopback from the router. The CSU/DSU may want to do this so that its own network management diagnostics can independently check the integrity of the connection between the CSU/DSU and the router.
Use this command to enable a two-way, internal, and external loopback request on the HSSI from the CSU/DSU.
Caution
enabling this function prevents spurious line noise from accidentally tripping the external
loopback request line, which would interrupt the normal data flow.
Examples
The following example enables a CSU/DSU to use the LC signal to request a loopback from the router:
Router(config-if)# hssi external-loop-requesthssi internal-clock
To convert the High-Speed Serial Interface (HSSI) into a clock master, use the hssi internal-clock command in interface configuration mode. To disable the clock master mode, use the no form of this command.
hssi internal-clock
no hssi internal-clock
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command in conjunction with the HSSI null-modem cable to connect two Cisco routers together with HSSI. You must configure this command at both ends of the link, not just one.
Note
the type of service to which it is connected.Examples
The following example shows how to convert the HSSI interface into a clock master:
Router(config-if)# hssi internal-clockhub
To enable and configure a port on an Ethernet hub of a Cisco 2505 or Cisco 2507 router, use the hub command in global configuration mode.
hub ethernet number port [end-port]
Syntax Description
Defaults
No hub ports are configured.
Command Modes
Global configuration
Command History
Usage Guidelines
This command does not have a no form.
Examples
The following example enables port 1 on hub 0:
Router# hub ethernet 0 1Router(config-hub)# no shutdownThe following example enables ports 1 through 8 on hub 0:
Router# hub ethernet 0 1 8Router(config-hub)# no shutdownRelated Commands
shutdown (hub)
Shuts down a port on an Ethernet hub of a Cisco 2505 or Cisco 2507 router.
hw-module main-cpu qa error-recovery
To enable the recovery mechanism for a QA error condition on a Cisco 7500 series router, use the hw-module main-cpu qa error-recovery command in global configuration mode. To disable the recovery mechanism for a QA error condition, use the no form of this command.
hw-module main-cpu qa error-recovery
no hw-module main-cpu qa error-recovery
Syntax Description
This command has no arguments or keywords.
Defaults
In Cisco IOS Release 12.0(24)S1, the recovery mechanism for a QA error condition is disabled; in all other releases, it is enabled.
Command Modes
Global configuration
Command History
Usage Guidelines
QA errors are sometimes seen in heavy traffic situations and may indicate a hardware failure or a software bug. In the case of a hardware failure, a Versatile Interface Processor (VIP) or a Route Switch Processor (RSP) must be replaced. It is possible, however, to recover from a QA error and not see another error for months. When the same buffer header is present in two different queues, the QA ASIC goes into an error condition and triggers a QA error interrupt. The QA error interrupt causes the RSP to dump the QA diagnostics and perform a cbus complex during which all the line cards are reloaded. Although the duplicate buffer header condition does not always indicate a hardware failure, the downtime of up to 300 seconds creates a real problem in the network.
The hw-module main-cpu qa error-recovery command has been created to enable a recovery mechanism for a QA error by allowing the router to remove the duplicate buffer header from the queue that shows the problem and requeue the buffer header. By using the QA error recovery, the downtime is reduced to less than one second under lab conditions. Three QA errors caused by buffer headers are permitted before the router performs a cbus complex and reloads all the line cards.
After three QA errors caused by duplicate queued buffer headers occur, the cbus complex is initiated and the line cards reload. Other QA errors, such as a null buffer header on any queue, can occur. Recovery is not possible in these cases, and the QA error triggers a cbus complex and subsequent line-card reloads. The QA error condition is specific to the Cisco 7500 series routers.
Examples
The following example shows how to enable the QA error recovery mechanism when a Cisco IOS Release 12.0(24)S1 image is used on a Cisco 7500 series router. In all other supported releases, the QA error recovery mechanism is enabled by default.
Router(config)# hw-module main-cpu qa error-recoveryRelated Commands
hw-module sec-cpu reset
To reset and reload the standby Route Switch Processor (RSP) with the specified Cisco IOS image and to execute the image, use the hw-module sec-cpu reset command in privileged EXEC mode.
hw-module sec-cpu reset
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Before using this command, you must use the hw-module slot image global configuration command to specify a high availability Cisco IOS image to run on the standby RSP. After the high availability image is loaded in the active RSP, use the hw-module sec-cpu reset command to reset and reload the standby RSP with the specified Cisco IOS image and to execute the image. To load the standby RSP with the default micro-IOS software contained in the active RSP image instead of a high availability Cisco IOS image, use the no form of the hw-module slot image command followed by the hw-module sec-cpu reset command.
Examples
The following example shows a Cisco 7513 router with the standby RSP loaded in slot 7. The standby RSP is reset and reloaded with the rsp-pv-mz high availability Cisco IOS image. Both RSPs have slot 0 flash memory cards.
Router(config)# hw-module slot 7 image slot0:rsp-pv-mzRouter(config)# endRouter# hw-module sec-cpu resetRelated Commands
hw-module slot image
Specifies a high availability Cisco IOS image to run on an active or standby RSP.
hw-module slot
To enable the router shelf to restart a stopped Dial Shelf Controller (DSC) card, to stop a DSC card, or to cause a shutdown, reset, or reload of any specified dial shelf feature board, use the hw-module slot command in privileged EXEC mode.
hw-module slot shelf-id/slot-number {reload | reset | shutdown | start | stop}
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The stop form of this command is issued from the router shelf console instead of by pressing the attention (ATTN) button on the target DSC. Confirmation of when the start or stop took place is displayed. Warnings are issued and confirmation input is required if a stop command will result in a loss of service when backup functionality is not available.
When a DSC card is stopped, removed, and then reinstalled, there is no need to restart the card (whether the card is the original or a replacement) because a freshly installed card reboots as the backup DSC automatically. However, if a DSC is stopped, either by using the ATTN button or by issuing the hw-module slot stop command, it must be restarted by using the start form of the same command, or the DSC must be removed and reinstalled in order to reboot.
Press the ATTN button on the DSCs to shut down a card manually before removing the card. This is equivalent to issuing a hw-module slot command for that card at the router command prompt. Use the ATTN button to shut down the card before it is swapped out or tested in place, or to restart it, if the card has not been removed after having been shut down.
Tip
OIR event in the case of a feature board failure when physical access to the feature board card is restricted.Entering the hw-module slot shelf-id/slot-number reload command initiates the feature board reload process through power cycling. The hw-module slot shelf-id/slot-number reload command cannot be used to reload DSCs.
Use the reset form of this command to reset the specified feature card and drop all active calls.
Use the shutdown form of this command to shut down the specified feature card and drop all active calls.
Examples
The following example shows how to stop the DSC in slot 13 and start the other DSC in slot 12 (which was previously stopped):
Router# hw-module slot 1/13 stopRouter# hw-module slot 1/12 startThe following example shows how to reload the dial shelf feature board in slot 6:
Router# hw-module slot 1/6 reloadThe following example shows how to reset the card in slot 3:
Router# hw-module slot 1/3 resetThe following example shows how to shut down the PRE card located in slot 3:
Router# hw-module slot 1/3 shutdownRelated Commands
hw-module slot image
To specify a high availability Cisco IOS image to run on an active or standby Route Switch Processor (RSP), use the hw-module slot image command in global configuration mode. To remove a high availability Cisco IOS image from the running configuration, use the no form of this command.
hw-module slot slot-number image file-spec
no hw-module slot slot-number image file-spec
Syntax Description
slot-number
Specifies the number of the RSP slot.
file-spec
Specifies the flash memory card location to load the image into and the name of the image.
Defaults
No high availability Cisco IOS images are specified to run on the active or standby RSPs.
Command Modes
Global configuration
Command History
12.0(16)ST
This command was introduced.
12.3(7)T
This command was integrated into Cisco IOS Release 12.3(7)T.
Examples
The following example shows a Cisco 7513 router with the active RSP loaded in slot 6 and the standby RSP loaded in slot 7. The rsp-pv-mz high availability Cisco IOS image is specified to run on both the active and the standby RSP. Both RSPs have slot 0 flash memory cards.
Router(config)# hw-module slot 6 image slot0:rsp-pv-mzRouter(config)# hw-module slot 7 image slot0:rsp-pv-mzRelated Commands
