NetScaler Flexed licensing is the capacity-pool licence framework through which NetScaler sells ADC capacity under Citrix Universal Hybrid Multi-Cloud (UHMC) and Citrix Platform subscriptions. The documentation describes it as “the new licensing framework aimed at simplifying the license management process”: a Flexed licence includes software instance licences (VPX/CPX/BLX, SDX, MPX and VPX FIPS) and bandwidth capacity licences that are applied on NetScaler Console and then allocated across every form factor deployed in the cloud or on premises.[1] It succeeds the legacy Pooled capacity model, which NetScaler Console still hosts and the License Activation Service still supports.[4][10]
Where Flexed licences come from
When a customer buys a Universal Hybrid Multi-Cloud licence or a Citrix Platform Licence (CPL), the NetScaler licences delivered are referred to as Flexed licences.[3] The commercial packaging is in the Citrix product terms: each of UHMC and Citrix Platform includes 999 NetScaler software instances of each of VPX/CPX/BLX, MPX, SDX, VPX FIPS, and the MPX-Z and SDX-Z zero-capacity platform licences; UHMC limits NetScaler throughput to 1000 Gbps and Citrix Platform provides unlimited throughput capacity, in both cases with usage restricted to the licensed customer.[7] NetScaler’s pricing page describes the same two packages next to a stand-alone Fixed-Capacity licence.[13] Stand-alone Fixed-Capacity customers receive a “defined number of NetScaler software instances” and do not need NetScaler Console, so they do not use pools at all.[13]
In file-based deployments, the Flexed licence arrives as separately named files downloaded from the licensing portal with the NetScaler Console host ID:
| File name contains | Entitles | Applied on |
|---|---|---|
| NetScaler Flexed VPX SW Instance | VPX, CPX and BLX software instances | NetScaler Console |
| NetScaler Flexed MPX SW Instance | MPX software instances | NetScaler Console |
| NetScaler Flexed SDX SW Instance | SDX software instances | NetScaler Console |
| NetScaler Flexed VPX FIPS SW Instance | VPX FIPS software instances | NetScaler Console |
| NetScaler Flexed Platinum BW | Flexed Platinum throughput capacity | NetScaler Console |
| Zero Capacity MPX-Z Platform License | MPX hardware participating in Flexed licensing | The MPX appliance |
| Zero Capacity SDX-Z Platform License | SDX hardware participating in Flexed licensing | The SDX appliance |
Source: NetScaler Console licence management documentation.[3] With LAS-based licensing the zero-capacity platform files are no longer needed and entitlements are delivered as an activation blob instead.[1]
Pools
Flexed licensing has two kinds of pool. The instance pool is split into VPX/CPX/BLX software instances, MPX software instances (the same pool serves MPX FIPS), SDX software instances (the same pool serves SDX FIPS) and VPX FIPS software instances; when checked out, an instance licence unlocks the instance’s resources, including CPUs, SSL cores, packets per second and bandwidth.[1] The bandwidth pool is the total bandwidth that physical and virtual instances can share. In Flexed licensing it is normally a single Premium pool, but a customer who moved from Pooled licensing can see a mix of Standard, Advanced and Premium; a given instance cannot hold bandwidth from different pools at the same time, and which pool it uses depends on its software edition.[1] Legacy Pooled capacity always keeps separate Standard, Advanced and Premium bandwidth pools.[4]
Pooled and Flexed pools are managed by NetScaler Console configured as a licence server, and NetScaler documents that Console can manage Pooled capacity licences without a NetScaler Console licence.[4] For Flexed licences, Console 14.1-12.34 and later also provides a bundled entitlement of unlimited Console VIPs for analytics; on earlier builds Console treats Flexed licences as Pooled licences and the bundled VIP entitlement is not available.[3]
Zero-capacity hardware
MPX and SDX appliances managed through Flexed licensing are called zero-capacity hardware (MPX-Z and SDX-Z) because “these instances cannot function until they check resources out of the bandwidth pool”.[1] A Z-cap licence is installed on the appliance by hardware serial number or licence access code; once installed it is locked to the hardware and cannot be shared on demand, but may be moved manually to another appliance.[1] MPX running 11.1 build 54.14 or later and SDX running 11.1 build 58.13 or later support Flexed licensing.[1] A customer moving from Pooled to Flexed whose hardware already holds perpetual Z-cap licences need not apply the Z-cap files received with Flexed, unless the existing Z-cap licences are valid only for a specific period.[3] Product terms add that the zero-capacity hardware itself, like all MPX and SDX hardware, needs separately purchased hardware maintenance.[7]
Check-out limits
Each platform defines a minimum bandwidth below which the instance does not operate, a maximum, and a check-out unit. The documentation gives 10 Mbps as the minimum bandwidth checkout unit for CPX, BLX and VPX and 1 Gbps for MPX and SDX; every check-out must be an integer multiple, so on a 1 Gbps unit platform 1000 Mbps can be checked out but not 200 Mbps or 150.5 Gbps.[2] An instance can operate only after it holds at least the minimum bandwidth.[2] The LAS FAQ adds a practical point: for VPX, CPX and BLX the starting minimum is 20 Mbps and values that are not multiples of 10 Mbps are invalid; on affected Console on-prem releases (14.1-73.x or earlier) such values can leave an instance unlicensed after a reboot or in grace.[10]
Selected Flexed limits for MPX (all with a 1 Gbps unit):
| Platform | Minimum bandwidth (Gbps) | Maximum bandwidth (Gbps) |
|---|---|---|
| MPX 5900Z | 1 | 10 |
| MPX 8900Z | 5 | 30 |
| MPX 9100Z | 10 | 95 |
| MPX 14000Z | 20 | 100 |
| MPX 16000Z | 30 | 250 |
| MPX 26000Z | 100 | 200 |
Source: Table 1, minimum and maximum capacity for Flexed and Pooled licensing.[2] SDX has separate tables by release. For SDX 13.1 build 51.x and later, and 14.1 build 12.x and later, the 8900Z has a minimum of 5 Gbps and one instance, a maximum of 30 Gbps and seven instances, and the 16000Z has 30 to 250 Gbps and one to 55 instances; on SDX 14.1-12.x and later with a Flexed licence the restriction to check out a minimum number of instance licences is removed.[2] The documentation notes that the minimum purchase quantity can differ from the minimum system requirement.[2]
Software form factors have maximums by platform, with a 10 Mbps minimum and a single instance each:
| Platform | Maximum bandwidth |
|---|---|
| VPX on VMware ESXi or Linux KVM | 100 Gbps |
| VPX on Citrix Hypervisor | 40 Gbps |
| VPX on AWS | 30 Gbps |
| VPX on Azure or Google Cloud | 10 Gbps |
| VPX on Microsoft Hyper-V | 3 Gbps |
| BLX | 100 Gbps |
| CPX | 10 Gbps |
Source: Tables 3 to 5.[2]
CPX counting
CPX has an unusual rule. A single CPX instance consuming up to 1 Gbps checks out only one instance licence and no bandwidth; bandwidth is added in multiples of 10 Mbps. If a CPX instance consumes 1,500 Mbps, the first 1,000 Mbps is covered by the instance and the remaining 500 Mbps is taken from the pool, so a 20 Gbps pool shared by 20 CPX instances falls to 19.5 Gbps.[1] Container-level detail is in NetScaler ADC form factors licensing.
Legacy Pooled capacity, Starter Pools and Self Managed Pool
Pooled capacity lets bandwidth or instance licences be shared across NetScaler form factors, so that an instance returns capacity to the common pool when it no longer needs it.[4] The SKUs carry the keyword “Starter Pool”, for example a VPX/BLX/CPX Starter Pool of 20 Gbps Premium with 20 instances.[10] Under Pooled capacity the Management Service of an SDX-Z does not consume an instance licence, MPX needs no separate instance subscription, and SDX needs a zero-capacity hardware purchase plus bandwidth and instance subscriptions.[4] Add-on subscriptions for appliances can be bought only after the starter pool and after or with the corresponding appliances.[7]
A pooled subscription cannot be upgraded: edition and bandwidth upgrades are not supported, and a customer who wants another edition must buy a new pooled subscription and upload its licences; bandwidth upgrades do not apply because each instance can check out what it needs.[9]
From NetScaler release 13.1 build 30.x, instances also support a Self Managed Pool licence, which simplifies and automates licence file uploads to a licence server and uses NetScaler Console to hold a common bandwidth or vCPU and instance pool. Migration is possible only between compatible licences: Pooled capacity and Self Managed Pool in either direction, and vCPU and Self Managed vCPU in either direction.[8]
Legacy vCPU and check-in/check-out licences
Two older frameworks may still appear in inventories. Virtual CPU licensing specifies how many CPUs a VPX is entitled to; the VPX checks out licences for the CPUs running in the system and does not count idle CPUs, and a change in CPU count or edition requires shutting the instance down before requesting a new set. CPX instances check out one licence per core, with one to 16 cores supported. The vCPU licence “is no longer available for purchase”.[11] Check-in and check-out (CICO) licences let a VPX or BLX check a licence out of NetScaler Console when provisioned and check it back in when removed or destroyed.[12] Neither is supported by the License Activation Service. For Pooled vCPU licences with a contract end date beyond 15 April 2026, the LAS FAQ describes a replacement LAS-compatible licence for the remainder of the contract term.[10]
Transitions and expiry
The transition guide states that the switch to Flexed licensing must be made before the current licence expires, with a maintenance window planned where steps involve licence reconfiguration or a reboot. A Pooled Premium (Platinum) bandwidth licence switches to Flexed automatically when the old licence expires; Pooled Standard or Advanced customers must manually check out Premium bandwidth and warm reboot. Pooled vCPU and CICO VPX customers must remove the old licence server (the instance is unlicensed until the steps finish), add the licence server in Flexed/Pooled mode, check out instance and bandwidth licences and warm reboot.[5]
Renewal is seamless if done in time. When a new licence is uploaded before the old one expires, two pools of capacity exist and a running instance switches to the new Flexed or Pooled licence without a restart or capacity reconfiguration. If the term expires with no new licence, the instance stops normal operations, loses its configuration and stops processing traffic.[6]
Counting checklist
To compute an effective licence position for a pooled estate, record for each pool the licence file or LAS entitlement (instance type, edition, bandwidth, term end date), then for each instance the form factor, edition, instance licence checked out and bandwidth checked out. Compare the sum of check-outs with the pool, remember the CPX 1 Gbps rule and the SDX-Z management exception, and confirm that every MPX and SDX has the right zero-capacity entitlement.
Out of scope
Fixed bandwidth subscriptions and perpetual licences are covered in NetScaler ADC form factors licensing, the activation mechanism in NetScaler License Activation Service and Gateway licensing in the form factors article.