Router Hardware Management Guide for Cisco 8000 Series Routers, Cisco IOS XR Release

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Router Hardware Management Guide for Cisco 8000 Series Routers, Cisco IOS XR Release

Dynamic power management

Updated: July 1, 2026

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Describes dynamic power management, which allocates router power based on the installed cards and operating modes, reduces the number of required power supply units, and improves overall PSU efficiency.

The Dynamic Power Management feature is a power allocation mechanism that

considers dynamic factors, such as the type of fabric or line cards in the chassis, or the presence of a card in a slot before allocating power,
optimizes total power distribution, and
prevents overprovisioning of power to the router.

Table 1. Feature history table
Feature Name	Release Information	Description
Dynamic Power Management	Release 24.4.1	Introduced in this release on: Fixed Systems (8200 [ASIC: P100], 8700 [ASIC: P100])(select variants only); Modular Systems (8800 [LC ASIC: P100])(select variants only) *This feature is supported on: 8212-48FH-M 8711-32FH-M 88-LC1-36EH 88-LC1-12TH24FH-E 88-LC1-52Y8H-EM
Dynamic Power Management	Release 7.5.2	The Cisco 8202-32FH-M router will now consider dynamic factors, such as optical modules, NPU power profile, and MACsec mode to enable improved power allocation and use.
Dynamic Power Management	Release 7.3.15	The Dynamic Power Management feature considers certain dynamic factors before allocating power to the fabric and line cards. This feature has these benefits: Reduces number of PSUs required by accurately representing the maximum power consumption Improves PSU efficiency by providing more accurate power allocation This feature thus optimizes power allocation and avoids overprovisioning power to a router.
Dynamic Power Management	Release 7.3.3	The Dynamic Power Management feature is now supported on these Cisco 8100 and 8200 series routers: Cisco 8201 Cisco 8202 Cisco 8201-32-FH Cisco 8101-32-FH
Dynamic Power Management	Release 7.3.2	Previously available for fabric and line cards, this feature that helps avoid excess power allocation by considering dynamic factors before allocating power to them is now available for optical modules. To view the power allocation on a per port basis, a new command "show environment power allocated [details] " is introduced.

Benefits of dynamic power management

These are the benefits of using dynamic power management:

Reduces number of PSUs required by accurately representing the maximum power consumption
Improves PSU efficiency by providing more accurate power allocation
Optimizes power allocation and avoids overprovisioning power to a router.

Configuration guidelines and restrictions for dynamic power management

These guidelines apply to dynamic power management:

Supported platforms

We recommend you work with your Cisco account representatives to calculate power requirements for the Cisco 8000 series router.
The router enables this feature by default.
The feature supports the following Cisco 8000 series routers and line cards:
- Cisco 8804, Cisco 8808, Cisco 8812, and Cisco 8818 routers
- Cisco 8201, Cisco 8202, Cisco 8201-32-FH, and Cisco 8202-32FH-M routers
- Cisco 8101-32-FH
- Cisco 8212-48FH-M
- Cisco 8711-32FH-M
- 88-LC1-36EH
- 88-LC1-12TH24FH-E
- 88-LC1-52Y8H-EM

Power allocation parameters

The dynamic power management feature allocates the total power to a router and its fabric card or line card based on these parameters:

Number and type of fabric cards installed on the router
Fabric cards operating modes (5FC or 8FC)
Number and type of line cards installed on the router
Combination of line card and fabric card types installed
NPU power mode configured on a fabric card
Number and type of optics installed (supported in IOS XR Release 7.3.2 and later)
MACSec-enabled ports (supported from IOS XR 7.3.3 and later)

For details, refer to Dynamic Power Management for MACSec-Enabled Ports section in the Configuring MACSec chapter in the System Security Configuration Guide for Cisco 8000 Series Routers.

On 8202-32FH-M router, the dynamic power management feature allocates the total power to a router based on these parameters:

Optical modules installed.
NPU power profile. To identify the mode on which the router is operating, use the hw-module npu-power-profile command.
MACSec mode. By default, MACSec mode is disabled on 8202-32FH-M router.

Power allocation to empty card slot

The power allocation for empty card slots is a power management mechanism that

provides minimum power to empty line card or fabric card slots
enables immediate boot-up of CPU and FPGAs upon card insertion, and
facilitates card type detection before the system initiates data path power-up.

The feature allocates the minimum required power to all empty line card or fabric card slots. This power allows the CPU and FPGAs to boot immediately upon card insertion. The feature doesn't control booting up the CPU and FPGAs. Instead, the system uses this power to detect the card type before determining if sufficient power exists to activate the data path.

For example, the show environment power command output displays various LC or FC card statuses, and also shows allocated and used power.

Note

The allocated power capacity shown in this show command output isn't standard capacity. The allocated power capacity varies depending on various other factors.

Router# show environment power
Thu Apr 22 12:03:06.754 UTC
================================================================================
CHASSIS LEVEL POWER INFO: 0
================================================================================
   Total output power capacity (N + 1)             :    9600W +     6300W
   Total output power required                     :    9241W
   Total power input                               :    6146W
   Total power output                              :    5826W

================================================================================
   Power       Supply         -------Input--------   -----Output---     Status
   Module      Type            Volts A/B   Amps A/B   Volts     Amps
================================================================================
   0/PT0-PM0   PSU6.3KW-HV     245.5/245.7 5.1/5.0    54.7      43.1     OK
   0/PT0-PM1   PSU6.3KW-HV     0.0/245.2   0.0/7.4    54.3      31.7     OK
   0/PT0-PM2   PSU6.3KW-HV     0.0/246.9   0.0/7.5    54.1      32.3     OK

Total of Power Modules:       6146W/25.0A              5826W/107.1A

================================================================================
   Location     Card Type               Power       Power        Status
                                        Allocated   Used
                                        Watts       Watts
================================================================================
   0/RP0/CPU0   8800-RP                 95          69           ON
   0/RP1/CPU0   -                       95          -            RESERVED
   0/0/CPU0     88-LC0-36FH             796         430          ON
   0/1/CPU0     -                       102         -            RESERVED
   0/2/CPU0     88-LC0-36FH             796         430          ON
   0/3/CPU0     -                       102         -            RESERVED
   0/4/CPU0     -                       102         -            RESERVED
   0/5/CPU0     -                       102         -            RESERVED
   0/6/CPU0     -                       102         -            RESERVED
   0/7/CPU0     -                       102         -            RESERVED
   0/8/CPU0     -                       102         -            RESERVED
   0/9/CPU0     88-LC0-36FH             102         -            OFF
   0/10/CPU0    -                       102         -            RESERVED
   0/11/CPU0    -                       102         -            RESERVED
   0/FC0        -                       26          -            RESERVED
   0/FC1        -                       26          -            RESERVED
   0/FC2        -                       26          -            RESERVED
   0/FC3        8812-FC                 784         509          ON
   0/FC4        8812-FC                 784         503          ON
   0/FC5        8812-FC                 26          -            OFF
   0/FC6        8812-FC                 26          -            OFF
   0/FC7        8812-FC                 26          -            OFF
   0/FT0        8812-FAN                1072        1000         ON
   0/FT1        8812-FAN                1072        1012         ON
   0/FT2        8812-FAN                1072        861          ON
   0/FT3        8812-FAN                1072        1033         ON

This table describes the card slot statuses:

Table 2. Router card slot status
Status	Description
RESERVED	When a slot is empty
OFF	When a card is inserted in a slot but power isn't allocated to the card
ON	When a card is allocated power and the card is in operational state

Low-power condition

The low-power condition is a power management state that

prevents power provisioning to new cards when resources are insufficient
triggers the ev_power_budget_not_ok alarm, and
initiates a graceful shutdown of the affected card.

When you insert an LC or FC in a card slot at the time when the router doesn't have enough power available to allocate to the new card, the dynamic power management feature doesn't provision power to the card. It raises the ev_power_budget_not_ok alarm, and gracefully shuts down the card.

This example shows the output of the show shelfmgr history events location command, which illustrates how the router gracefully shuts down an FC in the card slot location 0/FC6 due to ack of power:

Router# show shelfmgr history events location 0/FC6
Thu Apr 22 12:03:11.763 UTC
NODE NAME     : 0/FC6
CURRENT STATE : CARD_SHUT_POWERED_OFF
TIME STAMP    : Apr 20 2021 16:49:52
--------------------------------------------------------------------------------
DATE        TIME (UTC)  EVENT                    STATE
--------------------------------------------------------------------------------
Apr 20 2021 16:49:52    ev_powered_off           CARD_SHUT_POWERED_OFF
Apr 20 2021 16:49:52    ev_device_offline        STATE_NOT_CHANGED
Apr 20 2021 16:49:52    ev_unmapped_event        STATE_NOT_CHANGED
Apr 20 2021 16:49:48    transient_condition      CARD_SHUTDOWN
Apr 20 2021 16:49:48    ev_check_card_down_reaso CHECKING_DOWN_REASON
Apr 20 2021 16:49:48    ev_timer_expiry          CARD_SHUTDOWN_IN_PROGRESS
Apr 20 2021 16:48:46    ev_power_budget_not_ok   CARD_SHUTDOWN_IN_PROGRESS
Apr 20 2021 16:48:45    transient_condition      POWER_BUDGET_CHECK
Apr 20 2021 16:48:45    ev_fpd_upgrade_not_reqd  CARD_STATUS_CHECK_COMPLETE
Apr 20 2021 16:47:45    ev_card_status_check     CARD_STATUS_CHECK
Apr 20 2021 16:47:45    ev_card_info_rcvd        CARD_INFO_RCVD
Apr 20 2021 16:47:44    ev_device_online         DEVICE_ONLINE
Apr 20 2021 16:47:43    ev_timer_expiry          CARD_POWERED_ON
Apr 20 2021 16:47:33    ev_powered_on            CARD_POWERED_ON
Apr 20 2021 16:47:33    init                     CARD_DISCOVERED
--------------------------------------------------------------------------------

The router imposes the following limitations regarding power management and system reloads:

The dynamic power management feature does not guarantee that previously operational LCs, FCs, optics, or interfaces will become active again following an LC, FC, or chassis reload.
The router does not borrow power from a redundant power supply during a low-power condition.

Power allocation to optics

Power allocation for optics is a power management process that

considers power requirements for optics during allocation
automates power assignment upon the insertion of optical modules, and
enables interface activation through the no shut command.

To identify the power allocated for a particular interface, use the show environment power allocated [details ] location location command.

Router# show environment power allocated location 0/3/CPU0
Thu Oct  7 22:27:35.732 UTC
================================================================================
   Location    Components               Power
                                        Allocated
                                        Watts
================================================================================
  0/3/CPU0     Data-path                772
               OPTICS                   138
================================================================================
               Total                    910

Router# show environment power allocated details location 0/3/CPU0
Thu Oct  7 22:27:42.221 UTC
================================================================================
   Location    Components               Power
                                        Allocated
                                        Watts
================================================================================
  0/3/CPU0     Data-path                772
               0/3/0/0                  3
               0/3/0/1                  3
               0/3/0/2                  3
               0/3/0/3                  3
               0/3/0/4                  3
               0/3/0/5                  3
               0/3/0/6                  3
               0/3/0/7                  3
               0/3/0/8                  3
               0/3/0/9                  3
               0/3/0/10                 3
               0/3/0/11                 3
               0/3/0/12                 3
               0/3/0/13                 3
               0/3/0/14                 3
               0/3/0/15                 3
               0/3/0/16                 3
               0/3/0/17                 3
               0/3/0/18                 3
               0/3/0/19                 3
               0/3/0/20                 3
               0/3/0/21                 3
               0/3/0/22                 3
               0/3/0/23                 3
               0/3/0/24                 3
               0/3/0/25                 3
               0/3/0/26                 3
               0/3/0/27                 3
               0/3/0/28                 3
               0/3/0/29                 3
               0/3/0/30                 3
               0/3/0/31                 3
               0/3/0/32                 3
               0/3/0/33                 3
               0/3/0/34                 3
               0/3/0/35                 3
               0/3/0/36                 3
               0/3/0/37                 3
               0/3/0/38                 3
               0/3/0/39                 3
               0/3/0/40                 3
               0/3/0/41                 3
               0/3/0/42                 3
               0/3/0/43                 3
               0/3/0/44                 3
               0/3/0/46                 3    
================================================================================
               Total                    910

The router provides specific feedback when power allocation fails:

The system generates a POWER ALLOCATION FAIL syslog error and a major alarm when it lacks sufficient power to enable an optical module.

!<--Syslog Error-->!
#LC/0/3/CPU0:Oct  7 22:46:48.114 UTC: optics_driver[165]: %PKT_INFRA-FM-3-FAULT_MAJOR : ALARM_MAJOR :POWER ALLOCATION FAIL :DECLARE :0/3/CPU0:  Optics0/3/0/44
LC/0/3/CPU0:Oct  7 22:46:48.114 UTC: optics_driver[165]: %L2-OPTICS-2-QSFP_POWER_ALLOCATION_FAILURE : Not enough power available to enable Optics 0/3/0/44

!<--Alarm-->!
Router#show alarms brief system active
Thu Oct  7 22:47:19.569 UTC

------------------------------------------------------------------------------------
Active Alarms
------------------------------------------------------------------------------------
Location        Severity     Group            Set Time                   Description
------------------------------------------------------------------------------------
0/3/CPU0        Major        Software         10/07/2021 22:46:48 UTC     Optics0/3/0/44 - hw_optics:  Lack of available power to enable the optical module
0/3/CPU0        Major        Software         10/07/2021 22:47:06 UTC     Optics0/3/0/46 - hw_optics:  Lack of available power to enable the optical module

The system displays a PLATFORM-VEEA-1-PORT_NOT_ENABLED syslog error if a user attempts to enable an interface using the no shut command without sufficient power allocation.
```
LC/0/2/CPU0:Aug 30 18:01:14.930 UTC: eth_intf_ea[262]: %PLATFORM-VEEA-1-PORT_NOT_ENABLED : Power not allocated to enable the interface HundredGigE0_2_0_6.
```

Power allocation to fixed-port routers

The power allocation for fixed-port routers is a power management function that

displays total power capacity and requirements
identifies power allocated for specific interfaces, and
provides granular power distribution data for router components.

This table describes the commands to monitor power metrics and their examples:This show environment power command output displays power information for fixed-port routers and components.

Command	Description	Example
`show environment power`	Use this command to view comprehensive power information for the chassis and its components.	Router# show environment power Wed Feb 16 21:05:10.001 UTC ================================================================================ CHASSIS LEVEL POWER INFO: 0 ================================================================================ Total output power capacity (Group 0 + Group 1) : 1400W + 1400W Total output power required : 1033W Total power input : 390W Total power output : 255W Power Group 0: ================================================================================ Power Supply ------Input---- ------Output--- Status Module Type Volts Amps Volts Amps ================================================================================ 0/PM0 PSU1.4KW-ACPE 244.5 0.8 12.0 11.1 OK Total of Group 0: 195W/0.8A 133W/11.1A Power Group 1: ================================================================================ Power Supply ------Input---- ------Output--- Status Module Type Volts Amps Volts Amps ================================================================================ 0/PM1 PSU1.4KW-ACPE 244.2 0.8 12.0 10.2 OK Total of Group 1: 195W/0.8A 122W/10.2A ================================================================================ Location Card Type Power Power Status Allocated Used Watts Watts ================================================================================ 0/RP0/CPU0 8201 893 - ON 0/FT0 FAN-1RU-PE 28 - ON 0/FT1 FAN-1RU-PE 28 - ON 0/FT2 FAN-1RU-PE 28 - ON 0/FT3 FAN-1RU-PE 28 - ON 0/FT4 FAN-1RU-PE 28 - ON
show environment power allocated`[` details`]` locationlocation	Use this command command to identify the power allocated for a particular interface.	`Router# show environment power allocated location 0/RP0/CPU0 Wed Feb 16 21:05:21.360 UTC ================================================================================ Location Components Power Allocated Watts ================================================================================ 0/RP0/CPU0 Data-path 858 OPTICS 35 ================================================================================ Total 893` `Router# show environment power allocated details location 0/RP0/CPU0 Wed Feb 16 21:05:36.142 UTC ================================================================================ Location Components Power Allocated Watts ================================================================================ 0/RP0/CPU0 Data-path 858 0/0/0/19 21 0/0/0/18 14 ================================================================================ Total 893`

Command

Description

Example

show environment power

Use this command to view comprehensive power information for the chassis and its components.

Router# show environment power
Wed Feb 16 21:05:10.001 UTC
================================================================================
CHASSIS LEVEL POWER INFO: 0
================================================================================
   Total output power capacity (Group 0 + Group 1) :    1400W +     1400W
   Total output power required                     :    1033W
   Total power input                               :     390W
   Total power output                              :     255W

Power Group 0:
================================================================================
   Power       Supply         ------Input----   ------Output---     Status
   Module      Type            Volts     Amps    Volts     Amps
================================================================================
   0/PM0       PSU1.4KW-ACPE   244.5     0.8     12.0      11.1     OK

Total of Group 0:              195W/0.8A         133W/11.1A

Power Group 1:
================================================================================
   Power       Supply         ------Input----   ------Output---     Status
   Module      Type            Volts     Amps    Volts     Amps
================================================================================
   0/PM1       PSU1.4KW-ACPE   244.2     0.8     12.0      10.2     OK

Total of Group 1:              195W/0.8A         122W/10.2A

================================================================================
   Location     Card Type               Power       Power        Status
                                        Allocated   Used
                                        Watts       Watts
================================================================================
   0/RP0/CPU0   8201                    893         -            ON
   0/FT0        FAN-1RU-PE              28          -            ON
   0/FT1        FAN-1RU-PE              28          -            ON
   0/FT2        FAN-1RU-PE              28          -            ON
   0/FT3        FAN-1RU-PE              28          -            ON
   0/FT4        FAN-1RU-PE              28          -            ON

show environment power allocated[ details] locationlocation

Use this command command to identify the power allocated for a particular interface.

Router# show environment power allocated location 0/RP0/CPU0
Wed Feb 16 21:05:21.360 UTC
================================================================================
   Location    Components               Power
                                        Allocated
                                        Watts
================================================================================
  0/RP0/CPU0   Data-path                858
               OPTICS                   35
================================================================================
               Total                    893

Router# show environment power allocated details location 0/RP0/CPU0
Wed Feb 16 21:05:36.142 UTC
================================================================================
   Location    Components               Power
                                        Allocated
                                        Watts
================================================================================
  0/RP0/CPU0   Data-path                858
               0/0/0/19                 21
               0/0/0/18                 14
================================================================================
               Total                    893

Disable dynamic power management

By default, the dynamic power management is enabled on a router. This example shows how to disable dynamic power management:

Procedure

	1.	Enter the global configuration mode. Example: `Router# configure`
	2.	Use the power-mgmt action disable command to disable dynamic power management. Example: `Router(config)#power-mgmt action disable`
	3.	Save the changes. Example: `Router(config)#commit` Caution After disabling the dynamic power management feature, you must manage the router power on your own. So, use this command with caution.
	4.	To enable dynamic power management again, use the no power-mgmt action disable command.

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Dynamic power management

Benefits of dynamic power management

Configuration guidelines and restrictions for dynamic power management

Supported platforms

Power allocation parameters

Power allocation to empty card slot

Low-power condition

Power allocation to optics

Power allocation to fixed-port routers

Disable dynamic power management

Procedure

Example:

Example:

Example: