Configuration Limits

First Published: September 2, 2025

Last Updated: March 16, 2026

Configuration Limits

The limits in this document indicate the maximum scale capability tested for the corresponding feature individually. This number is the absolute maximum currently supported by Cisco UCS Manager for the corresponding feature. When used in combination, the practical limit for each feature may be lower than the maximum limit cited in this document.

Ethernet Environment Configuration Limits

Feature

Cisco UCS 6454 & 64108

Cisco UCS 6536

Cisco UCSX-S9108-100G

Cisco UCS 6664

Cisco UCS 6652

Active VLANs per Cisco UCS Domain

3000

This is the combined total of VLANs and VSANs that can be configured on each fabric interconnect. Of that total, no more than 32 can be VSANs.

3000

This is the combined total of VLANs and VSANs that can be configured on each fabric interconnect. Of that total, no more than 32 can be VSANs.

3000

This is the combined total of VLANs and VSANs that can be configured on each fabric interconnect. Of that total, no more than 32 can be VSANs.

3000

This is the combined total of VLANs and VSANs that can be configured on each fabric interconnect. Of that total, no more than 32 can be VSANs.

3000

This is the combined total of VLANs and VSANs that can be configured on each fabric interconnect. Of that total, no more than 32 can be VSANs.

VLAN/VSAN ID space per Cisco UCS Domain

4030-4047 and 4095 are reserved and fixed

4030-4047 and 4095 are reserved and fixed

4030-4047 and 4095 are reserved and fixed

4030-4047 and 4095 are reserved and fixed

4030-4047 and 4095 are reserved and fixed

STP logical Interfaces (also referred to as VLAN port count) per fabric interconnect *

108000

108000

32000

108000

108000

Note

 

*The only exception is for failover vNICs. These consume resources on a per Cisco UCS Domain basis.

Supported up to 108,000 VLAN port count per fabric interconnect, verified in large-scale deployments for 6400/6536/6664 with VLAN Port Count Optimization enabled.

VIFs (virtual interfaces) per fabric interconnect that map through VM-FEX to a vNIC or VM itself *

1600

1600

256

1600

1600

Note

 

*The only exception is for failover vNICs. These consume resources on a per Cisco UCS Domain basis.

IGMP groups per Cisco UCS Domain

16000

16000

2000

16000

16000

Uplink port channels per fabric interconnect

12*

12

8

12

12

Note

 

*When there is a mix of FC SAN port channels and FCoE SAN port channels, then together they cannot exceed a total of 8 port channels in the system.

FC SAN port channels + FCoE SAN port channels: 8 (4 +4, 3+ 5, 2+ 6, 1+7, or 0+8)

Maximum number of uplinks per fabric interconnect (including up to12 port channels)

31

31

8

31

31

Member interfaces per port channel

16

16

16

16

16

Interfaces per FCoE SAN port channel

16

16

16

16

16

Primary VLANs per Cisco UCS Domain*

200

200

42

200

200

Note

 

*Private VLANs count towards the total number of VLANs.

Secondary VLANs per Cisco UCS Domain

1000

1000

126

1000

1000

Maximum secondary VLANs per primary VLANs.

200

200

126

200

200

QOS system classes per Cisco UCS Domain

6 (including the class default)

6 (including the class default)

6 (including the class default)

6 (including the class default)

6 (including the class default)

VIC Environment Configuration Limits

Static Virtual NICs per Host for Cisco UCS 6400, 6500, 6600, and UCSX-S9108-100G Fabric Interconnects

OS vNICs vHBAs Max Combination of vNICs and vHBAs

Windows

20

16

12 Enics and 8 Fnics

Ubuntu

32

N/A

32 Enics

ESXi

26

16

18 Enics and 8 Fnics

or 24 Enics and 2 Fnics

Oracle

18

6

18 Enics and 6 Fnics

Linux

  • Red Hat Enterprise Linux

  • XenServer

  • SUSE Linux Enterprise Server

  • CentOs

  • Rocky Linux

  • Red Hat CoreOS

32

16

24 Enics and 8 Fnics

Note

For supported Operating System versions, see UCS Hardware and Software Compatibility.

Fibre Channel Environment Configuration Limits

Feature

Cisco UCS 6400 Series

Cisco UCS 6536

Cisco UCSX-S9108-100G

Cisco UCS 6664

Cisco UCS 6652

VSANs

32

32

32

32

32

Zones

  • Per VSAN—4000

  • Across all VSANS—4000

If you implement Cisco UCS Manager-based zoning, the maximum number of targets per service profile is 64.

  • Per VSAN—4000

  • Across all VSANS—4000

If you implement Cisco UCS Manager-based zoning, the maximum number of targets per service profile is 64.

  • Per VSAN—4000

  • Across all VSANS—4000

If you implement Cisco UCS Manager-based zoning, the maximum number of targets per service profile is 64.

  • Per VSAN—4000

  • Across all VSANS—4000

If you implement Cisco UCS Manager-based zoning, the maximum number of targets per service profile is 64.

  • Per VSAN—4000

  • Across all VSANS—4000

If you implement Cisco UCS Manager-based zoning, the maximum number of targets per service profile is 64.

Native FC links

16

Ports 1 to 16 support native FC

Note

 

For UCS 6454, the number of FC links was increased from 8 to 16 in Cisco UCS Manager Release 4.0(4a).

16

Ports 1/33/1 to 1/36/4 support native FC

8

Ports 1/1/1 to 1/2/4 support native FC

16

Ports 1/25 to 1/40 support native FC

16

Ports 1/25 to 1/40 support native FC

Virtual Fibre Channel interfaces per fabric interconnect

320

320

64

320

320

Virtual Fibre Channel interfaces per blade

16

16

16

16

16

FC-NVMe initiators per blade

4

4

4

4

4

Flogis per fabric interconnect

320

320

64

320

320

Maximum number of FC SAN port channels

4

4

4

4

4

Maximum port channel members per port channel

16

16

8

16

16

Port channel mode in NPV

Active

Active

Active

Active

Active

Port channel mode in FC switching

On

On

On

On

On

General Network Configuration Limits

Feature Cisco UCS 6400 Series

Cisco UCS 6500 Series

Cisco UCSX-S9108-100G

Cisco UCS 6600 Series

Unicast MAC addresses per fabric interconnect

96000 entries

96000 entries

24000 entries

96000 entries

Multicast MAC addresses per fabric interconnect

7000

7000

2000

7000

Secured interfaces per Cisco UCS domain

1000

1000 out of the 2000 VIFs can be port-secured.

1000

1000 out of the 2000 VIFs can be port-secured.

256

1000

1000 out of the 2000 VIFs can be port-secured.

Secured MAC addresses per Cisco UCS domain

8000

MAC addresses secured using the port-security feature.

8000

MAC addresses secured using the port-security feature.

8000

MAC addresses secured using the port-security feature.

8000

MAC addresses secured using the port-security feature.

Maximum MTU (Driven by the QoS Configuration)

9216

9216

9216

9216

1G ports

6454 - 4 (45-48)

64108 - 8 Ports (89-96)

6536 - 2 unified ports (Ports 9 and to 10)

Cisco UCSX-S9108-100G (Ports 7 and 8)

-

SPAN active sessions per fabric interconnect

4

4

4

4

Appliance ports per fabric interconnect

16

16

8

16

General Management Configuration Limits

Feature Cisco UCS 6400 Series

Cisco UCS 6500 Series

Cisco UCSX-S9108-100G

Cisco UCS 6600 Series

Chassis per Cisco UCS domain

20

20

2

20

Maximum combined number of blade and rack servers per Cisco UCS domain

160

160

20

160

Note

 

This value has been validated for stability and responsiveness in high-scale environments with Cisco UCS Manager Release 6.0.

Maximum number of Fabric Extenders per Cisco UCS domain

There is a limit of twenty FEX for each UCS domain. For example, you can either have ten 93180YC-FX3 FEX for each FI or a combination of ten chassis and ten FEX.

20 (10 per fabric interconnect)

20 (10 per fabric interconnect)

N/A

20 (10 per fabric interconnect)

Local user accounts per Cisco UCS domain

48

48

48

48

Concurrent logins per user account

48

This total includes a maximum of 24 concurrent GUI and a maximum of 24 concurrent CLI logins per user account.

This value is the same for both local and remote user accounts.

48

This total includes a maximum of 24 concurrent GUI and a maximum of 24 concurrent CLI logins per user account.

This value is the same for both local and remote user accounts.

16

This total includes a maximum of 8 concurrent GUI and a maximum of 8 concurrent CLI logins per user account.

This value is the same for both local and remote user accounts.

48

This total includes a maximum of 24 concurrent GUI and a maximum of 24 concurrent CLI logins per user account.

This value is the same for both local and remote user accounts.

Active KVM sessions per individual CIMC

4

4

4

4

Concurrent CLI logins per Cisco UCS Manager

32

32

16 (Default & Recommended - 8)

32

Concurrent GUI logins per Cisco UCS Manager

256

256

256

256

Number of LDAP groups per Cisco UCS Manager

160

160

160

160

Number of adapter end points per Cisco UCS Manager

320

320

16

320