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

Verify UDC port traffic statistics

Updated: June 18, 2026

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Use this procedure to verify that UDC ports are operational and traffic is flowing after a software upgrade or downgrade by using switch statistics commands on NCS 1010, NCS 1014, and NCS 1020.

After a software upgrade or downgrade that crosses Release 26.1.1, UDC traffic may be interrupted for approximately 100 seconds. It automatically recovers after this period.

Follow these steps to ensure that the UDC ports have returned to the Up state and that traffic is flowing without errors.

Procedure

1.

Run the show controller switch statistics command to view the statistics of all switch port states and packet counts.

Example:

RP/0/RP0/CPU0:ios# show controller switch statistics location 0/RP0/CPU0

The command displays a table of all switch ports. Locate the rows for UDC0 and UDC1 and verify these columns:

  • The Phys State column shows Up.

  • The Tx Drops/Errors and Rx Drops/Errors columns show 0.

Rack  Card  Switch   Rack Serial Number
-----------------------------------------
  0   RP0   RP-SW    <serial-number>

                                                      Tx        Rx
      Phys    State     Tx             Rx          Drops/    Drops/
Port  State   Changes   Packets        Packets     Errors    Errors  Connects To
...
10    Up      3         2316362958     2314924341  0         0       UDC0
11    Up      3         2314924559     2316363174  0         0       UDC1
...
2.

Run the show controller switch statistics detail command to view detailed Rx and Tx counters for each UDC port.

Example:

RP/0/RP0/CPU0:ios# show controller switch statistics detail location 0/RP0/CPU0

Locate the sections for UDC0 (physical port 10) and UDC1 (physical port 11) in the output.

The output displays detailed per-port counters. To confirm normal operation, verify these items in the UDC0 and UDC1 sections:

  • Rx Unicast Packets and Tx Unicast Packets show non-zero values that increment over time, indicating that traffic is flowing.

  • All error counters — including Rx Bad Octets, Rx Errors, Rx Bad CRC, Rx Policing Drops, Tx FIFO Underrun/CRC, Tx Policing Drops, and Tx Queueing Drops — show 0.

Rack   Card    Switch      Port    State   Speed    Connects To
------------------------------------------------------------------------
0      RP0     RP-SW       11      Up      1-Gbps   UDC1

Rx Unicast Packets:      <incrementing>
Rx Bad Octets:           0
Rx Errors:               0
Rx Bad CRC:              0
Rx Policing Drops:       0
Tx Unicast Packets:      <incrementing>
Tx FIFO Underrun/CRC:    0
Tx Policing Drops:       0
Tx Queueing Drops:       0
3.

Run the show controller switch statistics summary command to view the summary of all switch port states and packet counts.

Example:

RP/0/RP0/CPU0:ios# show controller switch statistics summary

When a controller card is inserted into slot 1 of an NCS 1020 equipped with a filler card, the show controllers switch summary command displays the port speed as 'Unknown' and the port state as 'Forwarding’.

If both UDC ports indicate a physical state of Up, show zero error and drop counts, and have incrementing unicast packet counters, then UDC traffic has recovered from the software upgrade or downgrade.