To delay the processing of hardware link down notifications, use the carrier-delay command in interface configuration mode.

Note

The carrier-delay command is active only when both up and down are configured from the host. The range of carrier-delay on access port of ASR 9000v is 1 to 60000 msec. If a value of 0 is set, the default value of 100 msec is applied. A value greater than 60000 msec will be ignored and show interfaces output will display the previously configured msec. Both up and down must be set to the same value. If the values are different, the smaller value will be set for both up and down configuration.

Command Default

No carrier-delay is used, and the upper layer protocols are notified as quickly as possible when a physical link goes down.

Command Modes

Interface configuration

Usage Guidelines

When you delay the processing of hardware link down notifications, the higher layer routing protocols are unaware of a link until that link is stable.

If the carrier-delay down milliseconds command is configured on a physical link that fails and cannot be recovered, link down detection is increased, and it may take longer for the routing protocols to re-route traffic around the failed link.

In the case of very small interface state flaps, running the carrier-delay down milliseconds command prevents the routing protocols from experiencing a route flap.

Note	Enter the show interface command to see the current state of the carrier-delay operation for an interface. No carrier-delay information is displayed if carrier-delay has not been configured on an interface.

Related Commands

To clear Media Access Control (MAC) accounting statistics, use the clear mac-accounting command in EXEC mode.

Command Default

No default behavior or values

Command Modes

EXEC

Usage Guidelines

Related Commands

To configure full-duplex operation on a Fast Ethernet interface, use the duplex full command in interface configuration mode. To return the system to the default duplex operation, use the no form of the duplex full command.

Syntax Description

This command has no keywords or arguments.

Command Default

If autonegotiation is disabled on an interface, then the default duplex operation is full duplex.

Command Modes

Interface configuration

Usage Guidelines

The duplex full command automatically replaces the duplex half command if half duplex was previously configured on your router.

Note	The duplex full command and the duplex half command cannot be configured simultaneously.

Related Commands

To configure half-duplex operation on a Fast Ethernet interface, use the duplex half command in interface configuration mode. To return the system to the default duplex operation, use the no form of the duplex half command.

Syntax Description

This command has no keywords or arguments.

Command Default

If autonegotiation is disabled on an interface, then the default duplex operation is full duplex.

Command Modes

Interface configuration

Usage Guidelines

The duplex half command automatically replaces the duplex full command if full duplex was previously configured on your router.

Note	The duplex half command and the duplex full command cannot be configured simultaneously.

Related Commands

To enable the sending of flow-control pause frames, use the flow-control command in interface configuration mode. To disable flow control, use the no form of this command.

Command Default

If autonegotiate is enabled on the interface, then the default is negotiated.

If autonegotiate is disabled on the interface, then the sending of flow-control pause frames is disabled for both egress and ingress traffic.

Command Modes

Interface configuration

Usage Guidelines

Note

When you explicitly enable the sending of flow-control pause frames, the value you configured with the flow-control command overrides any autonegotiated value. This prevents a link from coming up if the value you set with the flow-control command conflicts with the allowable settings on the other end of the connection.

Note	The flow-control command is supported on Gigabit Ethernet, TenGigE, and FastEthernet interfaces only; the flow-control command is not supported on Management Ethernet Interfaces.

Note	The flow-control command syntax options may vary, depending on the type of PLIM or SPA that is installed in your router.

Related Commands

To specify or create an Ethernet interface and enter interface configuration mode, use the interface (Ethernet) command in global configuration mode.

Command Default

None

Command Modes

Global configuration (config)

Usage Guidelines

Related Commands

To configure an Ethernet controller for loopback mode, use the loopback command in interface configuration mode. To disable loopback, use the no form of this command.

Command Default

Loopback mode is disabled.

Command Modes

Interface configuration

Usage Guidelines

The loopback command is available for all Ethernet interface types (Gigabit Ethernet, 10-Gigabit Ethernet, and Fast Ethernet).

Two loopback operation modes are supported for diagnostic purposes: internal and line. In the terminal (internal) loopback, the sent signal is looped back to the receiver. In the facility (line) loopback, the signal received from the far end is looped back and sent on the line. The two loopback modes cannot be active at the same time. In normal operation mode, neither of the two loopback modes is enabled.

Tip	Use the loopback external command when an external loopback connector is attached to the interface.

To generate accounting information for IP traffic based on the source and destination Media Access Control (MAC) addresses on LAN interfaces, use the mac-accounting command in interface configuration mode. To disable MAC accounting, use the no form of this command.

Command Default

MAC accounting is disabled

Command Modes

Interface configuration

Usage Guidelines

The mac-accounting command calculates the total packet and byte counts for a LAN interface that receives or sends IPv4 packets to or from a unique MAC address.

Related Commands

To set the MAC layer address of an Ethernet interface, use the mac-address command in interface configuration mode. To return the device to its default MAC address, use the no form of this command.

Command Default

The default MAC address is read from the hardware burned-in address (BIA).

Command Modes

Interface configuration

Usage Guidelines

The MAC address must be in the form of three 4-digit values (12 digits in dotted decimal notation).

The mac-address command is available for all types of line card Ethernet interfaces (Gigabit Ethernet, 10-Gigabit Ethernet, Fast Ethernet) and for the Management Ethernet interface.

To enable link autonegotiation on Gigabit Ethernet Fast Ethernet interfaces, use the negotiation auto command in interface configuration mode. To disable link autonegotiation, use the no form of this command.

Syntax Description

This command has no keywords or arguments.

Command Default

Link autonegotiation is disabled.

Command Modes

Interface configuration

Usage Guidelines

The negotiation auto command is available on Gigabit Ethernet Fast Ethernet interfaces only.

To change the packet interval for traffic on an interface for improved interoperability with Cisco Catalyst 6000 series switches, use the packet-gap non-standard command in interface configuration mode. To use the standard packet interval as defined by the IEEE 802.ae specification, use the no form of this command.

Syntax Description

This command has no keywords or arguments.

Command Default

The interface uses the standard packet interval as defined by the IEEE 802.ae specification.

Command Modes

Interface configuration

Usage Guidelines

An interface that is connected to a Cisco Catalyst 6000 series switch may experience packet loss problems that can be resolved by changing the packet interval of traffic from standard (as defined by the IEEE 802.ae specification) to nonstandard using the packet-gap non-standard command.

Note	The packet-gap non-standard command is available on 10-Gigabit Ethernet interfaces only.

To display status and configuration information about the Ethernet interfaces on a specific node, use the show controllers command in EXEC mode.

Command Default

No default behavior or values

Command Modes

EXEC mode

Usage Guidelines

For the interface-path-id argument, use the following guidelines:

• If specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:

  • rack: Chassis number of the rack.

  • slot: Physical slot number of the line card.

  • module: Module number. A physical layer interface module (PLIM) is always 0.

  • port: Physical port number of the interface.

• If specifying a virtual interface, the number range varies, depending on interface type.

To display MAC accounting statistics for an interface, use the show mac-accounting command in EXEC mode.

Command Default

No default behavior or values

Command Modes

EXEC

Usage Guidelines

For the interface-path-id argument, use these guidelines:

• If specifying a physical interface, the naming notation is rack/slot/module/port. The slash between values is required as part of the notation. An explanation of each component of the naming notation is as follows:

  • rack: Chassis number of the rack.

  • slot: Physical slot number of the line card.

  • module: Module number. A physical layer interface module (PLIM) is always 0.

  • port: Physical port number of the interface.

• If specifying a virtual interface, the number range varies, depending on interface type.

Related Commands

To configure the speed for a Fast Ethernet interface, enter the speed command in interface configuration mode. To return the system to autonegotiate speed, use the no form of this command.

Command Default

If autonegotiation is enabled on an interface, the default speed is negotiated.

If autonegotiation is disabled on an interface, the default speed is the maximum speed allowed on the interface.

Command Modes

Interface configuration

Usage Guidelines

Note	The speed command is available on Management Ethernet interfaces and Fast Ethernet interfaces only.

Note	Keep in mind that both ends of a link must have the same interface speed. A manually configured interface speed overides any autonegotiated speed, which can prevent a link from coming up if the configured interface speed at one end of a link is different from the interface speed on the other end.