Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

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Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

Hold-off timer

Updated: September 23, 2026

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This section describes hold-off times, their function in trunk fault scenarios, and their impact on network stability.

When a fault occurs on the trunk port, you can hold the propagation of local faults using the hold-off time feature. This feature is can be enabled on the Ethernet controllers of 1.2T, 2.4T, 2.4Tx, QXP, 2-QDD-C, and 2.4TA cards by configuring the hold-off timer.

When the fault occurs on the trunk, idles are inserted in the traffic stream from the trunk port to the client port for the duration of the configured holdoff-time. If the trunk port remains faulty beyond the configured holdoff-time, a local fault is transmitted towards the client device. If the trunk recovers from the fault before the holdoff-time expires, traffic resumes.

This feature can be used on customer deployments to prevent reset of client ports during a PSM switchover.

Configure holdoff-time on QXP Card

Use this task to configure holdoff-time on 100GE or 400GE controllers for the QXP card.

Procedure

  1. Run the controller HundredGigECtrlr Rack/Slot/Instance/Port holdoff-time trunk-fault time-value command to configure holdoff-time on the 100GE controllers for the QXP card.

    The range of timevalue is from 0 ms to 3000 ms.

    Example:

    This is a sample where holdoff-time is enabled on the 100GE controller for the QXP card.

    
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#controller HundredGigECtrlr 0/1/0/1
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#holdoff-time trunk-fault 3000
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#commit

    Example:

    This is a sample to view the holdoff-time status on the 100GE controller.

    
RP/0/RP0/CPU0:ios#show controller hundredGigECtrlr 0/1/0/1
Fri Jul 23 16:07:11.541 UTC
Operational data for interface HundredGigECtrlr0/1/0/1:

State:
    Administrative state: enabled
    Operational state: Up
    LED state: Green On
    Maintenance: Disabled
    AINS Soak: None
      Total Duration: 0 hour(s) 0 minute(s)
      Remaining Duration: 0 hour(s) 0 minute(s) 0 second(s)
    Laser Squelch: Enabled

Phy:
    Media type: Not known
Statistics:
FEC:
Corrected Codeword Count: 134967789
Uncorrected Codeword Count: 0

Autonegotiation disabled.

Operational values:
    Speed: 100Gbps
    Duplex: Full Duplex
    Flowcontrol: None
    Loopback: None (or external)
    BER monitoring:
        Not supported
        Forward error correction: Standard (Reed-Solomon)
    Holdoff Time: 3000ms

  2. Run the controller fourHundredGigECtrlr Rack/Slot/Instance/Port holdoff-time trunk-fault time-value command to configure holdoff-time on the 400GE controllers for the QXP card.

    Example:

    This is a sample where holdoff-time is enabled on the 400GE controller for the NCS1K4-QXP-K9 card.

    
RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#controller fourHundredGigECtrlr 0/0/0/10
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#holdoff-time trunk-fault 2000
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#commit

    Example:

    This is a sample to view the holdoff-time status on the 400GE controller.

    
RP/0/RP0/CPU0:ios#show controller fourhundredGigECtrlr 0/0/0/10
Fri Jul 23 16:07:11.541 UTC
Operational data for interface fourHundredGigECtrlr0/0/0/10:

State:
    Administrative state: enabled
    Operational state: Up
    LED state: Green On
    Maintenance: Disabled
    AINS Soak: None
      Total Duration: 0 hour(s) 0 minute(s)
      Remaining Duration: 0 hour(s) 0 minute(s) 0 second(s)
    Laser Squelch: Enabled

Phy:
    Media type: Not known
Statistics:
FEC:
Corrected Codeword Count: 134967789
Uncorrected Codeword Count: 0

Autonegotiation disabled.

Operational values:
    Speed: 400Gbps
    Duplex: Full Duplex
    Flowcontrol: None
    Loopback: None (or external)
    BER monitoring:
        Not supported
        Forward error correction: Standard (Reed-Solomon)
    Holdoff Time: 2000ms