POS interface commands -- alarm-detect

| NOTE: Support for this command depends on the device model.

‌

Use alarm-detect to configure the action to take when an RDI, SD, or SF alarm occurs on an interface.

Use undo alarm-detect to restore the default.

Syntax

alarm-detect { rdi | sd | sf } action link-down

undo alarm-detect { rdi | sd | sf }

Default

The device does not take any actions on the interface when an RDI, SD, or SF alarm occurs.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

rdi: Specifies remote defect indication (RDI) alarms.

sd: Specifies signal degrade (SD) alarms.

sf: Specifies signal fail (SF) alarms.

action: Specifies the action to take when the specified alarm is detected on the interface.

link-down: Places the interface in down state.

Usage guidelines

An RDI alarm occurs if the device receives multiplexer section remote defect indication (MS-RDI) signals from the remote end.

An SD or SF alarm occurs if the bit error rate of incoming packets crosses the SD or SF alarm threshold. To set the SD or SF alarm threshold, use the threshold command.

Examples

# Configure POS 2/2/1 to go down when an SD alarm occurs.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] alarm-detect sd action link-down

Related commands

threshold

POS interface commands -- bandwidth

Use bandwidth to configure the expected bandwidth of an interface.

Use undo bandwidth to restore the default.

Syntax

bandwidth bandwidth-value

undo bandwidth

Default

The expected bandwidth (in kbps) is the interface baud rate divided by 1000.

Views

Standard POS interface view

POS subinterface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

bandwidth-value: Specifies the expected bandwidth in the range of 1 to 400000000 kbps.

Usage guidelines

The expected bandwidth is an informational parameter used only by higher-layer protocols for calculation. You cannot adjust the actual bandwidth of an interface by using this command.

Examples

# Set the expected bandwidth to 50 kbps for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] bandwidth 50

POS interface commands -- clock

Use clock to set the clock mode of a standard POS interface.

Use undo clock to restore the default.

Syntax

clock { master | slave }

undo clock

Default

The clock mode of a POS interface is slave.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

master: Sets the clock mode to master.

slave: Sets the clock mode to slave.

Usage guidelines

Standard POS interfaces support the following clock modes:

· Master—Uses internal clock signal.

· Slave—Uses line clock signal.

If the standard POS interface is connected to another router, set its clock mode to be different from the mode used by the remote end. If the standard POS interface is connected to a SONET/SDH device, which provides higher clock precision, always set its clock mode to slave.

Examples

# Set the clock mode to master for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] clock master

POS interface commands -- crc

Use crc to set the CRC length on an interface.

Use undo crc to restore the default.

Syntax

crc { 16 | 32 }

undo crc

Default

The CRC length on an interface is 32 bits.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

16: Sets the CRC length to 16 bits.

32: Sets the CRC length to 32 bits.

Usage guidelines

The CRC length must be the same at both ends.

Examples

# Set the CRC length to 16 bits on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] crc 16

POS interface commands -- dampening

Use dampening to enable the device to dampen an interface when it is flapping.

Use undo dampening to disable interface dampening.

Syntax

dampening [ half-life reuse suppress max-suppress-time ]

undo dampening

Default

Interface dampening is disabled on POS interfaces.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

half-life: Specifies the amount of time (in seconds) for a penalty to decrease by half of its value. The value range is 1 to 120 seconds, and the default is 54 seconds.

reuse: Specifies the reuse threshold. The value range is 200 to 20000, and the default is 750. The reuse threshold must be lower than the suppression threshold.

suppress: Specifies the suppression threshold. The value range is 200 to 20000, and the default is 2000.

max-suppress-time: Specifies the maximum amount of time an interface can be dampened. The value range is 1 to 255 seconds, and the default is 162 seconds (three times the default half-life timer).

Usage guidelines

This command, the link-delay command, and the port link-flap protect enable command are mutually exclusive with each other on an interface.

This command does not take effect on the administratively down events. When you execute the shutdown command, the penalty restores to 0, and the interface reports the down event to the higher layer protocols.

For more information about the interface dampening feature, see Interface Configuration Guide.

Examples

# Configure interface dampening on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] dampening 2 800 3000 5

Related commands

display interface pos

link-delay

port link-flap protect enable

POS interface commands -- default

Use default to restore the default settings for an interface.

Syntax

default

Views

Standard POS interface view

POS subinterface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

| CAUTION: The default command might interrupt ongoing network services. Make sure you are fully aware of the impact of this command when you use it on a live network.

‌

This command might fail to restore the default settings for some commands for reasons such as command dependencies or system restrictions. You can use the display this command in interface view to check for these commands, and use their undo forms or follow the command reference to restore their default settings. If your restoration attempt still fails, follow the error message to resolve the problem.

Examples

# Restore the default settings of POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] default

POS interface commands -- description

Use description to configure the description of an interface.

Use undo description to restore the default.

Syntax

description text

undo description

Default

The interface description uses the interface-name Interface format, for example, Pos2/2/1 Interface.

Views

Standard POS interface view

POS subinterface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

text: Specifies the description, a case-sensitive string of 1 to 255 characters.

Examples

# Configure the description of POS 2/2/1 as pos-interface.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] description pos-interface

POS interface commands -- display interface pos

Use display interface pos to display information about POS interfaces.

Syntax

display interface [ pos [ interface-number | interface-number.subnumber ] ] [ brief [ description | down ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

pos [ interface-number | interface-number.subnumber ]: Specifies a standard POS interface, POS channel interface, or POS subinterface. The interface-number.subnumber arguments specify a POS subinterface. The interface-number argument specifies the main interface number, and the subnumber argument specifies the subinterface number in the range of 0 to 1023. If you do not specify the pos keyword, this command displays information about all interfaces on the device. If you specify the pos keyword without specifying an interface, this command displays information about all POS interfaces.

brief: Displays brief interface information. If you do not specify this keyword, the command displays detailed interface information.

description: Displays complete interface descriptions. If you do not specify this keyword, the command displays only the first 27 characters of interface descriptions.

down: Displays physically down interfaces and their down causes. If you do not specify this keyword, the command displays information about interfaces in any state.

Examples

# Display detailed information about POS 2/2/1.

<Sysname> display interface pos 2/2/1

Pos2/2/1

Current state: DOWN

Line protocol state: DOWN

Description: Pos2/2/1 Interface

Bandwidth: 50kbps

Maximum transmission unit: 1500

Dampening enabled:

Penalty: 0 (not suppressed)

Ceiling: 4525

Reuse: 800

Suppress: 3000

Half-life: 2 seconds

Max-suppress-time: 5 seconds

Flap count: 0

Hold timer: 10 seconds, retry times: 5

Internet Address: 5.5.5.2/24 Primary

Link layer protocol: PPP

LCP: opened, IPCP: opened

Physical layer: Packet Over SONET, Baudrate: 155520000 bps

Scramble: enabled, crc: 32, clock: slave, loopback: not set

SONET alarm:

section layer: OOF LOF LOS

line layer: AIS

path layer: AIS RDI

C2(Rx): 0xff, C2(Tx): 0x16

J0(Rx): unknown

J0(Tx): ""

J1(Rx): unknown

J1(Tx): ""

SONET error:

section layer: B1 65535

line layer: B2 0 M1 0

path layer: B3 0 G1 0

Last link flapping: 6 hours 39 minutes 25 seconds

Last clearing of counters: Never

Last 300 seconds input rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec

Last 300 seconds output rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec

Input:

0 packets, 0 bytes

0 errors, 0 runts, 0 giants, 0 CRC

0 overruns, 0 aborts, 0 no buffers

Output:

0 packets, 0 bytes

0 errors, 0 underruns, 0 aborts

# Display brief information about POS 2/2/1.

<Sysname> display interface pos 2/2/1 brief

Brief information on interfaces in route mode:

Link: ADM - administratively down; Stby - standby

Protocol: (s) - spoofing

Interface Link Protocol Primary IP Description

Pos2/2/1 DOWN DOWN --

# Display brief information about all standard POS interfaces, POS subinterfaces, and POS channel interfaces in a down state and the causes.

<Sysname> display interface pos brief down

Brief information on interfaces in route mode:

Link: ADM - administratively down; Stby - standby

Interface Link Cause

Pos2/2/1 ADM Administratively

Table 1 Command output

Field | Description
Current state | Physical link state of the interface: · Administratively DOWN—The interface has been shut down by using the shutdown command. · DOWN—The interface is administratively up, but its physical state is down (possibly because no physical link exists or the link has failed). · Link-Flap DOWN—The interface has been shut down by the link flapping protection feature. · UP—The interface is both administratively and physically up.
Line protocol state | Data link layer state of the interface. The state is determined through automatic parameter negotiation at the data link layer. · UP—The data link layer protocol is up. · DOWN—The data link layer protocol is down.
Description | Description of the interface.
Bandwidth | Expected bandwidth of the interface.
Maximum transmission unit | MTU of the interface.
Dampening enabled: Penalty: 0 (not suppressed) Ceiling: 4525 Reuse: 800 Suppress: 3000 Half-life: 2 seconds Max-suppress-time: 5 seconds Flap count: 0 | Interface dampening information: · Dampening enabled—The dampening feature is enabled. · Penalty—Penalty value. The interface suppression state is displayed in parentheses. ?span style='font:7.0pt "Times New Roman"'> Not suppressed—The interface is not dampened. Interface state changes are reported to higher layer protocols. ?span style='font:7.0pt "Times New Roman"'> Suppressed—The interface is dampened. Interface state changes are not reported to higher layer protocols. · Ceiling—Maximum penalty value. · Reuse—Reuse threshold. · Suppress—Suppression threshold. · Half-life—Half-life timer. · Max-suppress-time—Maximum suppression time. · Flap count—Number of times that the interface has flapped. These fields are not displayed if dampening is disabled on the interface. Support for the interface dampening feature depends on the device model.
Hold timer | Interval at which the data link layer protocol sends keepalives.
retry times | Maximum number of keepalive attempts. The interface determines that the remote end is down if it does not receive a keepalive response after the maximum number of keepalive attempts have been made.
Internet protocol processing: Disabled | The interface is not assigned an IP address and cannot process IP packets.
Internet Address | IP address of the interface. The primary attribute indicates that the address is the primary IP address.
Link layer protocol | Data link layer protocol of the interface.
LCP: opened, IPCP: opened | Both LCP negotiation and IPCP negotiation succeeded.
Physical layer | Physical interface.
Baudrate | Baud rate of the interface.
Scramble | Payload scrambling state.
crc | CRC length.
clock | Clock mode.
loopback | Loopback state.
SONET alarm | SONET alarms.
SONET error | SONET errors.
Last link flapping | The amount of time that has elapsed since the most recent physical state change of the interface. This field displays Never if the interface has been physically down since device startup.
Last clearing of counters | The most recent time that the reset counters interface pos command was executed. This field displays Never if the command has not been executed on the interface since device startup.
Last 300 seconds input rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec | Average input rates (in Bps, bps, and pps) for the last 300 seconds.
Last 300 seconds output rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec | Average output rates (in Bps, bps, and pps) for the last 300 seconds.
Input: 0 packets, 0 bytes 0 errors, 0 runts, 0 giants, 0 CRC 0 overruns, 0 aborts, 0 no buffers | Inbound traffic statistics for the POS interface: · errors—Number of inbound packets with errors detected at the physical layer. · runts—Number of inbound packets shorter than the minimum frame length. · giants—Number of inbound packets larger than the maximum frame length. · CRC—Total number of inbound normal-size packets with CRC errors. · overruns—Number of packet drops because the input rate of the interface exceeded the forwarding capability. · aborts—Number of invalid inbound frames. · no buffers—Number of packet drops because the receive buffer is full.
Output: 0 packets, 0 bytes 0 errors, 0 underruns, 0 aborts | Outbound traffic statistics for the POS interface: · errors—Number of outbound packets with errors detected at the physical layer. · underruns—Number of packets dropped because the output rate of the interface exceeded the memory reading rate. · aborts—Total number of invalid outbound packets.
Brief information on interface(s) under route mode: | Brief information about Layer 3 interfaces.
Interface | Abbreviated interface name.
Link | Physical link state of the interface: · UP—The interface is physically up. · DOWN—The interface is physically down. · ADM—The interface has been shut down by using the shutdown command. To restore the physical state of the interface, use the undo shutdown command. · Stby—The interface is a backup interface in standby state. To see the primary interface, use the display interface-backup state command.
Protocol | Data link layer protocol state of the interface: · UP—The data link layer protocol of the interface is up. · DOWN—The data link layer protocol of the interface is down. · UP(s)—The data link layer protocol of the interface is up, but the link is an on-demand link or does not exist. The (s) attribute represents the spoofing flag.
Primary IP | Primary IP address of the interface. This field displays two hyphens (--) if the interface does not have an IP address.
Description | Description of the interface.
Cause | Cause for the physical link state of an interface to be DOWN: · Administratively—The interface has been manually shut down by using the shutdown command. To restore the physical state of the interface, use the undo shutdown command. · Not connected—No physical connection exists (possibly because the network cable is disconnected or faulty).

‌

Related commands

reset counters interface pos

POS interface commands -- display link-flap protection

Use display link-flap protection to display information about link flapping protection on an interface.

Syntax

display link-flap protection [ interface pos [ interface-number ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

interface-number: Specifies a POS interface number. If you do not specify a POS interface number, the command displays information about link flapping protection on all POS interfaces.

Examples

# Display information about link flapping protection on POS interfaces.

<Sysname> display link-flap protection interface pos

Link-flap protection: Enable

Interface Link-flap Status Interval Threshold

Pos2/2/1 Enabled Down 10 5

Table 2 Command output

Field | Description
Link-flap protection | Status of link flapping protection on all interfaces: · Enable—Link flapping protection is enabled on all interfaces. · Disable—Link flapping protection is disabled on all interfaces.
Link-flap | Status of link flapping protection on an interface: · Enabled—Link flapping protection is enabled on an interface. · Disabled—Link flapping protection is disabled on an interface.
Status | Status of an interface: · Down—The interface has been shut down by the link flapping protection feature. · N/A—The interface status is not affected by the link flapping protection feature.
Interval | Link flapping detection interval for an interface.
Threshold | Link flapping detection threshold for an interface.

‌

Related commands

link-flap protect enable

port link-flap protect enable

POS interface commands -- flag c2

Use flag c2 to set the C2 path signal label byte.

Use undo flag c2 to restore the default.

Syntax

flag c2 flag-value

undo flag c2

Default

The C2 value is 16 in hexadecimal notation.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

flag-value: Specifies a C2 byte value, a hexadecimal number in the range of 0 to ff.

Usage guidelines

The C2 byte is a higher-order path overhead byte. It indicates the multiplex structure of virtual container (VC) frames and the property of payload.

The C2 byte must be the same at both ends of a link.

Examples

# Set the C2 byte to 01 in hexadecimal notation on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] flag c2 01

Related commands

display interface pos

POS interface commands -- flag j0

Use flag j0 to set the J0 regenerator section trace byte for SONET or SDH frames.

Use undo flag j0 to restore the default.

Syntax

flag j0 { sdh | sonet } flag-value

undo flag j0 { sdh | sonet }

Default

The device uses the SDH framing format. In SDH frames, the J0 byte value varies by device model.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

flag-value: Specifies the J0 byte. It must be a string of 1 to 15 characters for SDH, and a hexadecimal number in the range of 0 to ff for SONET.

sdh: Specifies the SDH framing format.

sonet: Specifies the SONET framing format.

Usage guidelines

J0 byte is a section overhead byte. SDH and SONET use this byte to test continuity of the connection between two interfaces at the section level.

The J0 byte can be different on devices of the same service provider. On the interfaces between two service providers, the J0 byte must be the same.

Examples

# Set the J0 byte to ff in hexadecimal notation for SDH on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] flag j0 sdh ff

Related commands

display interface pos

frame-format

POS interface commands -- flag j1

Use flag j1 to set the J1 path trace byte for SONET or SDH frames.

Use undo flag j1 to restore the default.

Syntax

flag j1 { sdh | sonet } flag-value

undo flag j1 { sdh | sonet }

Default

The device uses the SDH framing format. In SDH frames, the J1 byte value varies by device model.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

flag-value: Specifies a J1 byte value. It must be a string of 1 to 15 characters for SDH and a string of 1 to 62 characters for SONET.

sdh: Specifies the SDH framing format.

sonet: Specifies the SONET framing format.

Usage guidelines

J1 byte is a higher-order path overhead byte. SDH and SONET use this byte to test continuity of the connection between two interfaces at the path level.

The J1 byte must be the same at both ends of a link.

Examples

# Set the J1 byte to aabbcc for SDH on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] flag j1 sdh aabbcc

Related commands

display interface pos

flag j1 ignore

frame-format

POS interface commands -- flag j1 ignore

| NOTE: Support for this command depends on the device model.

‌

Use flag j1 ignore to ignore CRC of the J1 byte.

Use undo flag j1 ignore to restore the default.

Syntax

flag j1 ignore

undo flag j1 ignore

Default

CRC is performed for the J1 byte.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Examples

# Ignore CRC of the J1 byte on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] flag j1 ignore

Related commands

flag j1

POS interface commands -- flow-interval

| NOTE: Support for this command depends on the device model.

‌

Use flow-interval to set the packet statistics collection interval for an interface.

Use undo flow-interval to restore the default.

Syntax

flow-interval interval

undo flow-interval

Default

The default setting varies by device model.

Views

System view

Standard POS interface view

POS subinterface view

POS channel interface view

| NOTE: Support for the views depends on the device model.

‌

Predefined user roles

network-admin

mdc-admin

Parameters

interval: Specifies the packet statistics collection interval in the range of 5 to 300 and in steps of 5, in seconds.

Usage guidelines

You can use this command in system view or interface view.

· In system view, the command takes effect on all interfaces.

· In interface view, the command takes effect only on the specified interface.

Examples

# Set the packet statistics collection interval to 180 seconds for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] flow-interval 180

POS interface commands -- frame-format

Use frame-format to set the framing format on a standard POS interface.

Use undo frame-format to restore the default.

Syntax

frame-format { sdh | sonet }

undo frame-format

Default

The framing format is SDH on a standard POS interface.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

sdh: Specifies the SDH framing format.

sonet: Specifies the SONET framing format.

Usage guidelines

When you use the flag j0 and flag j1 commands to set the overhead bytes, the settings must match the framing format.

Examples

# Set the framing format to SONET on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] frame-format sonet

Related commands

flag j0

flag j1

POS interface commands -- interface pos

Use interface pos to create a POS subinterface and enter its view, or enter the view of an existing standard POS interface, POS channel interface, or POS subinterface.

Use undo interface pos to delete a POS subinterface.

Syntax

interface pos { interface-number | interface-number.subnumber [ p2mp | p2p ] }

undo interface pos interface-number.subnumber

Default

No POS subinterfaces exist.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

interface-number: Specifies a standard POS interface or POS channel interface by its number.

interface-number.subnumber: Specifies a POS subinterface. The interface-number argument specifies the main interface number. The subnumber argument specifies the subinterface number in the range of 0 to 1023.

p2mp: Sets the subinterface type to point-to-multipoint. By default, a POS subinterface is P2MP type.

p2p: Sets the subinterface type to point-to-point.

Usage guidelines

You can create POS subinterfaces only on Frame Relay-enabled standard POS interfaces.

Examples

# Create POS subinterface POS 2/2/1.1.

<Sysname> system-view

[Sysname] interface pos 2/2/1.1

[Sysname-Pos2/2/1.1]

Related commands

link-protocol

POS interface commands -- link-delay

| NOTE: Support for this command depends on the device model.

‌

Use link-delay to set the physical state change suppression interval on an interface.

Use undo link-delay to restore the default.

Syntax

link-delay msec milliseconds

undo link-delay

Default

The default setting varies by device model.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

msec milliseconds: Sets the physical state change suppression interval on an interface, in milliseconds. The value range for this argument varies by device model.

Usage guidelines

When the physical state changes, a POS interface reports the event to the upper-layer modules, and generates log and SNMP notification messages. To reduce system overhead caused by frequent physical state changes, use this command to suppress physical state changes within an interval. The interface will ignore any changes that occur during each suppression interval. When the suppression interval expires, the interface will not report the change event or generate messages if the change is removed.

For example, the suppression interval starts when the interface changes from up to down. The interface reports the change event and generates messages if it is still down when the interval expires. The interface does not report the change event or generate messages if it is up when the interval expires.

This command suppresses up state change, down state change, or both depending on the device model.

This command, the dampening command, and the port link-flap protect enable command are mutually exclusive with each other on an interface.

Examples

# Set the physical state change suppression interval to 100 milliseconds for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] link-delay msec 100

Related commands

dampening

port link-flap protect enable

POS interface commands -- link-flap protect enable

Use link-flap protect enable to enable link flapping protection on all interfaces.

Use undo link-flap protect enable to disable link flapping protection on all interfaces.

Syntax

link-flap protect enable

undo link-flap protect enable

Default

Link flapping protection is disabled on all interfaces.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Link flapping on any interface changes network topology and increases the system overhead. For example, in an active/standby link scenario, when the interface status on the active link changes between UP and DOWN, traffic switches between active and standby links. To solve this problem, execute this command.

With link flapping protection enabled on an interface, when the interface goes down, the system enables link flapping detection on the interface. During the link flapping detection interval, if the number of detected flaps reaches or exceeds the link flapping detection threshold, the system shuts down the interface.

Link flapping protection takes effect only when it is enabled in both the system view and interface view.

Examples

# Enable link flapping protection on all interfaces.

<Sysname> system-view

[Sysname] link-flap protect enable

Related commands

port link-flap protect enable

POS interface commands -- link-protocol

Use link-protocol to set the data link layer protocol of an interface.

Syntax

link-protocol { fr | hdlc | ppp }

Default

PPP is used.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

fr: Specifies Frame Relay as the data link layer protocol of the interface.

hdlc: Specifies HDLC as the data link layer protocol of the interface.

ppp: Specifies PPP as the data link layer protocol of the interface.

Examples

# Specify HDLC as the data link protocol of POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] link-protocol hdlc

POS interface commands -- loopback

Use loopback to enable loopback for a standard POS interface.

Use undo loopback to disable loopback for a standard POS interface.

Syntax

loopback { local | remote }

undo loopback

Default

Loopback is disabled on a standard POS interface.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

local: Enables internal loopback.

remote: Enables external loopback.

Usage guidelines

Loopback is intended for testing only. Disable the feature when the interface is operating correctly.

Before you use this command on a standard POS interface, make sure its clock mode is master.

If you enable internal loopback on an unconnected standard POS interface, the status of the data link layer protocol changes to up.

Examples

# Enable internal loopback on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] loopback local

Related commands

clock

POS interface commands -- mtu

Use mtu to set the MTU size for an interface.

Use undo mtu to restore the default.

Syntax

mtu size

undo mtu

Default

The default setting varies by device model.

Views

Standard POS interface view

POS subinterface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

size: Sets the maximum transmission unit (MTU) in bytes. The value range for this argument varies by device model.

Usage guidelines

The MTU setting affects the assembly and fragmentation of IP packets.

After configuring the MTU for an interface, you must use the shutdown command and then the undo shutdown command on the interface for the modification to take effect.

Examples

# Set the MTU to 1430 bytes for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] mtu 1430

POS interface commands -- port link-flap protect enable

Use port link-flap protect enable to enable link flapping protection on an interface.

Use undo port link-flap protect enable to disable link flapping protection on an interface.

Syntax

port link-flap protect enable [ interval interval | threshold threshold ] *

undo port link-flap protect enable [ interval | threshold ]

Default

Link flapping protection is disabled on an interface.

Views

POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

interval: Specifies the link flapping detection interval in seconds. The value range for this argument is 10 to 60. The default value for this argument is 10.

threshold: Specifies the link flapping detection threshold in the range of 5 to 10. The default value for this argument is 5.

Usage guidelines

Link flapping protection takes effect only when it is enabled in both the system view and interface view.

If you do not specify the interval interval or threshold threshold option when you execute the port link-flap protect enable command, the command uses the default settings.

If you specify the interval or threshold keyword when you execute the undo port link-flap protect enable command, the command restores the default setting for the keyword.

With link flapping protection enabled on an interface, when the interface goes down, the system enables link flapping detection on the interface. During the link flapping detection interval, if the number of detected flaps reaches or exceeds the link flapping detection threshold, the system shuts down the interface.

To bring up an interface that has been shut down by link flapping protection, execute the undo shutdown command.

This command, the dampening command, and the link-delay command are exclusive with each other on a POS interface.

Examples

# Enable link flapping protection on POS 2/2/1. Set the link flapping detection interval to 10 seconds, and set the link flapping detection threshold to 5.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-pos2/2/1] port link-flap protect enable interval 10 threshold 5

Related commands

dampening

link-delay

link-flap protect enable

POS interface commands -- port-type switch

| NOTE: Support for this command depends on the device model.

‌

Use port-type switch to change the type of an interface.

Syntax

In standard POS interface view:

port-type switch gigabitethernet

In Layer 3 GigabitEthernet interface view:

port-type switch pos

Views

Standard POS interface view

Layer 3 GigabitEthernet interface view

Predefined user roles

2: System level

Parameters

gigabitethernet: Change a standard POS interface to a Layer 3 GigabitEthernet interface.

pos: Change a Layer 3 GigabitEthernet interface to a standard POS interface.

Usage guidelines

When you execute this command, the device performs the following operations:

1. Removes the original interface.

2. Creates a new-type interface with the same number as the original interface.

3. Enters the interface view of the new-type interface.

Examples

# Change POS 2/2/1 to GigabitEthernet 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] port-type switch gigabitethernet

Changing port type can result in loss of port configuration. Are you sure to continue? [Y/N]:y

[Sysname-GigabitEthernet2/2/1]

POS interface commands -- reset counters interface pos

Use reset counters interface pos to clear interface statistics.

Syntax

reset counters interface [ pos [ interface-number | interface-number.subnumber ] ]

Views

User view

Predefined user roles

network-admin

mdc-admin

Parameters

pos [ interface-number | interface-number.subnumber ]: Clears statistics for a standard POS interface, POS channel interface, or POS subinterface. The interface-number.subnumber arguments specify a POS subinterface. The interface-number argument specifies the main interface number, and the subnumber argument specifies the subinterface number in the range of 0 to 1023. If you do not specify the pos keyword, this command clears statistics for all interfaces. If you specify the pos keyword without specifying an interface, this command clears statistics for all standard POS interfaces, POS subinterfaces, and POS channel interfaces.

Usage guidelines

Use this command to clear history statistics before you collect statistics for a time period.

Examples

# Clear statistics for POS 2/2/1.

<Sysname> reset counters interface pos 2/2/1

Related commands

display interface pos

POS interface commands -- scramble

Use scramble to enable payload scrambling on an interface.

Use undo scramble to disable payload scrambling on an interface.

Syntax

scramble

undo scramble

Default

Payload scrambling is enabled on standard POS interfaces and POS channel interfaces.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Payload scrambling enables an interface to scramble outgoing data and descramble incoming data. By preventing the presence of long strings of all 1s or all 0s, payload scrambling enables the receiving end to extract the line clock signal correctly.

If payload scrambling is disabled, the interface does not scramble outgoing data or descramble incoming data.

The payload scrambling setting must be the same at both ends of a link to ensure correct communication.

After payload scrambling is enabled or disabled on an interface, the C2 byte on the interface does not change automatically. Use the flag c2 command to set the same C2 byte on the interface as its peer.

Examples

# Enable payload scrambling on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1]scramble

POS interface commands -- shutdown

Use shutdown to shut down an interface.

Use undo shutdown to bring up an interface.

Syntax

shutdown

undo shutdown

Default

An interface is up.

Views

Standard POS interface view

POS subinterface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Examples

# Shut down POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] shutdown

POS interface commands -- snmp-agent trap enable { b1-tca | b2-tca | b3-tca }

| NOTE: Support for this command depends on the device model.

‌

Use snmp-agent trap enable { b1-tca | b2-tca | b3-tca } to enable SNMP notifications about signal transmission performance for a standard POS interface.

Use undo snmp-agent trap enable { b1-tca | b2-tca | b3-tca } to disable SNMP notifications about signal transmission performance for a standard POS interface.

Syntax

snmp-agent trap enable { b1-tca | b2-tca | b3-tca }

undo snmp-agent trap enable { b1-tca | b2-tca | b3-tca }

Default

Signal transmission performance notifications are enabled for the standard POS interface.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

To generate SNMP notifications when a B1, B2, or B3 alarm occurs on a standard POS interface, use this command.

B1, B2, and B3 bytes indicate the signal transmission performance of a line at different levels.

· B1 alarm occurs if the bit error rate of a complete STM-N frame exceeds the B1 alarm threshold.

· B2 alarm occurs if the bit error rate of an STM-1 frame exceeds the B2 alarm threshold.

· B3 alarm occurs if the bit error rate of a multiplexed signal (VC3 or VC4 frame) in the STM-1 frame exceeds the B3 alarm threshold.

For B1, B2, or B3 alarm SNMP notifications to be sent correctly, you must also configure SNMP on the device. For more information about SNMP configuration, see the network management and monitoring configuration guide for the device.

Examples

# Disable B1 alarm notifications on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] undo snmp-agent trap enable b1-tca

Related commands

threshold { b1-tca | b2-tca | b3-tca }

POS interface commands -- speed

| NOTE: Support for this command depends on the device model.

‌

Use speed to set the rate of a standard POS interface.

Use undo speed to restore the default.

Syntax

speed speed-value

undo speed

Default

The rate of a standard POS interface is 155 Mbps.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

speed-value: Specifies the rate in Mbps. The value range for this argument varies by device model.

Examples

# Set the rate to 2.5 Gbps for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] speed 2500

POS interface commands -- sub-interface rate-statistic

| NOTE: Support for this command depends on the device model.

‌

Use sub-interface rate-statistic to enable subinterface rate statistics collection on a POS interface.

Use undo sub-interface rate-statistic to disable subinterface rate statistics collection on a POS interface.

Syntax

sub-interface rate-statistic

undo sub-interface rate-statistic

Default

Subinterface rate statistics collection is disabled on a POS interface.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

This command is resource intensive. When you use this command, make sure you fully understand its impact on system performance.

Examples

# Enable subinterface rate statistics collection on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] sub-interface rate-statistic

POS interface commands -- threshold

| NOTE: Support for this command depends on the device model.

‌

Use threshold to configure the power for setting the SD or SF alarm threshold on a standard POS interface.

Use undo threshold to restore the default power for setting the SD or SF alarm threshold on a standard POS interface.

Syntax

threshold { sd sdvalue | sf sfvalue } *

undo threshold [ sd | sf ]

Default

The default setting varies by device model.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

sd: Specifies the SD alarm threshold.

sdvalue: Specifies the power for setting the SD alarm threshold. The threshold is 10e to the power of negative sdvalue (10e–sdvalue). The value range for this argument varies by device model. The greater the value, the lower the SD alarm threshold.

sf: Specifies the SF alarm threshold. The SF alarm threshold must be higher than the SD alarm threshold.

sfvalue: Specifies the power for setting the SF alarm threshold. The threshold is 10e to the power of negative sdvalue (10e–sfvalue). The value range for this argument varies by device model. The greater the value, the lower the SF alarm threshold.

Usage guidelines

SD and SF alarms indicate line performance. SF alarms are more severe than SD alarms.

· An SD alarm occurs if the number of B2 errors reaches the SD alarm threshold.

· An SF alarm occurs if the number of B2 errors reaches the SF alarm threshold.

Examples

# Set the SD threshold to 10e to the power of negative 4 (10e–4) on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] threshold sd 4

POS interface commands -- threshold { b1-tca | b2-tca | b3-tca }

| NOTE: Support for this command depends on the device model.

‌

Use threshold { b1-tca | b2-tca | b3-tca } to configure the power for setting the B1, B2, or B3 alarm threshold on a standard POS interface.

Use undo threshold { b1-tca | b2-tca | b3-tca } to restore the default power for setting the B1, B2, or B3 alarm threshold on a standard POS interface.

Syntax

threshold { b1-tca b1value | b2-tca b2value | b3-tca b3value }

undo threshold { b1-tca | b2-tca | b3-tca }

Default

The default setting varies by device model.

Views

Standard POS interface view

Predefined user roles

network-admin

mdc-admin

Parameters

b1value: Specifies the power for setting the B1 alarm threshold. The threshold is 10e to the power of negative b1value (10e–b1value). The value range for this argument is 3 to 9. The greater the value, the lower the B1 alarm threshold.

b2value: Specifies the power for setting the B2 alarm threshold. The threshold is 10e to the power of negative b2value (10e–b2value). The value range for this argument is 3 to 9. The greater the value, the lower the B2 alarm threshold.

b3value: Specifies the power for setting the B3 alarm threshold. The threshold is 10e to the power of negative b3value (10e–b3value). The value range for this argument is 3 to 9. The greater the value, the lower the B3 alarm threshold.

Usage guidelines

B1, B2, and B3 bytes indicate the signal transmission performance of a line at different levels.

· B1 alarm occurs if the bit error rate of a complete STM-N frame exceeds the B1 alarm threshold.

· B2 alarm occurs if the bit error rate of an STM-1 frame exceeds the B2 alarm threshold.

· B3 alarm occurs if the bit error rate of a multiplexed signal (VC3 or VC4 frame) in the STM-1 frame exceeds the B3 alarm threshold.

The B1, B2, and B3 alarm threshold settings take effect after SNMP notifications are enabled for these alarms.

Examples

# Set the B1 alarm threshold to 10e to the power of negative 4 (10e–4) on POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] threshold b1-tca 4

Related commands

snmp-agent trap enable { b1-tca | b2-tca | b3-tca }

POS interface commands -- timer-hold

Use timer-hold to set the keepalive interval.

Use undo timer-hold to restore the default.

Syntax

timer-hold seconds

undo timer-hold

Default

The keepalive interval is 10 seconds.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

seconds: Specifies the interval at which the interface sends keepalive packets. The value range for this argument is 0 to 32767 seconds.

Usage guidelines

On an interface encapsulated with PPP, FR, or HDLC, the data link layer sends keepalive packets at keepalive intervals to detect the availability of the remote end. The data link layer determines that the peer end is down if it does not receive a response after the maximum number of keepalive attempts have been made. The data link layer then reports the link down event to the upper-layer protocols.

To set the maximum number of keepalive attempts, use the timer-hold retry command.

On a slow link, increase the keepalive interval to prevent false shutdown of the interface. This situation might occur when keepalive packets are delayed because a large packet is being transmitted on the link.

Examples

# Set the keepalive interval to 15 seconds for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] timer-hold 15

Related commands

timer-hold retry

POS interface commands -- timer-hold retry

Use timer-hold retry to set the maximum number of keepalive attempts.

Use undo timer-hold retry to restore the default.

Syntax

timer-hold retry retries

undo timer-hold retry

Default

The maximum number of keepalive attempts is 5.

Views

Standard POS interface view

POS channel interface view

Predefined user roles

network-admin

mdc-admin

Parameters

retries: Specifies the maximum number of keepalive attempts, in the range of 1 to 255.

Usage guidelines

The interface determines that the remote end is down if it does not receive a keepalive response after the maximum number of keepalive attempts have been made.

This command applies to interfaces encapsulated with PPP, FR, or HDLC. To set the keepalive interval, use the timer-hold command.

On a slow link, increase the maximum number of keepalive attempts to prevent false shutdown of the interface. This situation might occur when keepalive packets are delayed because a large packet is being transmitted on the link.

Examples

# Set the maximum number of keepalive attempts to 10 for POS 2/2/1.

<Sysname> system-view

[Sysname] interface pos 2/2/1

[Sysname-Pos2/2/1] timer-hold retry 10

Related commands

timer-hold