Configuration Guide for Cisco NCS 1004, IOS XR Release 25.x.x

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Configuration Guide for Cisco NCS 1004, IOS XR Release 25.x.x

Idle insertion for Ethernet controllers

Updated: July 31, 2026

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This section explains the idle insertion feature available for Ethernet controllers on the NCS 1004 platform.

A idle insertion for Ethernet controllers is a link verification feature that

  • enables pre-provisioning end-to-end testing between 100GE or 400GE Ethernet controllers on the NCS 1004 before bringing up live traffic,

  • allows for insertion of idle frames in both ingress and egress directions to help isolate link errors without any Ethernet testers, and

  • is supported on 1.2T, 1.2TL, and 2-QDD-C cards, but does not support OTU4 client rate.

Feature history

Table 1. Feature history

Feature name

Release information

Feature description

Idle Insertion for Ethernet Controllers

Cisco IOS XR Release 7.5.2

Idle insertion for Ethernet controllers feature performs end-to-end link verification between 100GE or 400GE Ethernet controllers before bringing up the actual traffic. This feature enables you to perform pre-provisioning checks to isolate link errors in advance without any Ethernet testers. This feature is supported on the 1.2T C band, 1.2T L band, and 800G QSFP-DD Transponder line cards.

Behavior

Idle insertion for Ethernet controllers feature allows you to perform end-to-end link verification between 100GE or 400GE Ethernet controllers before bringing up the actual traffic. This feature is supported on the 1.2T, 1.2TL, and 2-QDD-C cards.

Note

OTU4 client rate is not supported.

Idle frames can be inserted in both the ingress and egress directions on Ethernet controllers and the LOCAL-FAULT and REMOTE-FAULT alarms are cleared. The performance monitoring counters on the pcs layer are monitored to check for any errors on the link.

Note

Do not configure the Idle insertion for Ethernet controllers feature on the link that carries live traffic.

The recommended topology for link verification is a network configuration that uses idle insertion to perform end-to-end link checks on 100GE or 400GE Ethernet controllers before enabling live traffic on the NCS 1004.

Link verification sequence

This diagram describes the recommended topology for link verification:

Figure 1. Topology for link verification
Topology for link verification

These steps describe the sequence for link verification using this topology:

  1. Both the near-end and far-end clients have the LOCAL-FAULT alarm if the trunk is up on both the ends.

  2. Enable idle ingress on the near-end client. The idle frame transmits toward the trunk link and reaches the far-end client. The LOCAL-FAULT alarm is then cleared on the far-end client.

  3. As the far-end client has fiber loop, the idle frame is inserted again into the same client RX toward the trunk link and reaches the near-end client. The LOCAL-FAULT alarm is then cleared on the near-end client as well.

  4. When you enable idle insertion on any client and in any direction, the idle frame transmits in loop similar to this topology and all the LOCAL-FAULT and the REMOTE-FAULT alarms are cleared.

  5. The link can be monitored after all the alarms are cleared. The link has a problem if any alarm is reported during the link test.

Configure idle insertion for Ethernet controllers

Enable or disable idle frame insertion on Ethernet controllers to facilitate link verification and manage alarm status.

Before you begin

  • Do not configure idle frame insertion together with a hold-off timer.

  • Do not configure PRBS on the trunk.

Follow these steps to configure idle insertion on Ethernet controllers:

Procedure

1.

Run the configure controller hundredGigECtrlr Rack/Slot/Instance/Port insert-idle ingress insert-idle egress command to enable idle insertion on the Ethernet controller.

Example:

This is a sample for enabling the idle ingress and idle egress in 100GE controllers:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#controller hundredGigECtrlr 0/2/0/2
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#insert-idle ingress
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#insert-idle egress
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#commit
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#end
2.

Run the configure controller hundredGigECtrlr Rack/Slot/Instance/Port no insert-idle ingress no insert-idle egress command to disable idle insertion on the Ethernet controller.

Example:

This is a sample for disabling the idle ingress and idle egress in 100GE controllers:

RP/0/RP0/CPU0:ios(config)#controller hundredGigECtrlr 0/2/0/2
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#no insert-idle ingress
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#no insert-idle egress
RP/0/RP0/CPU0:ios(config-eth-ctrlr)#commit

After disabling the idle frame insertion feature, the LOCAL-FAULT or REMOTE-FAULT alarm may not appear again because the idle frames are in loop. Hence, you must break the idle frame loop in the link by performing either one of the following:

  • Perform fiber OIR on either the near-end or far-end client port.

  • Perform shut and unshut operation on any client port.
3.

Run the show controllers hundredGigECtrlr command to verify the idle ingress and idle egress that is configured on the Ethernet controllers.

Example:


RP/0/RP0/CPU0:ios#show controllers hundredGigECtrlr 0/2/0/2
Wed Mar 30 06:56:58.878 UTC
Operational data for interface HundredGigECtrlr0/2/0/2:
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: Disabled
    
    Insert Idle Ingress: Enabled
    Insert Idle Egress: Enabled
    
Phy:
    Media type: Not known
    Statistics:
        FEC:
            Corrected Codeword Count: 0
            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: 0ms

Idle insertion is configured on the Ethernet controller. The LOCAL-FAULT and REMOTE-FAULT alarms are cleared when the idle frames are active. Monitor the PCS performance counters for any errors.