Short answer: VCF 9.1 Management Services (VCFMS) need a pool of at least 12 IP addresses on the VCF management network, and Broadcom recommends reserving 30 so you have room to scale. You can supply the pool as a CIDR block, a start–end range or a list of individual (even non-contiguous) addresses, and exclude reserved IPs. The UI covers the simple cases. The VCF Installer and SDDC Manager APIs cover the rest, including a custom network from 9.1.1.
What VCF Management Services are and why they need an IP pool
VCF management services are new in VCF 9.1. They bring fleet lifecycle, identity broker, log management, real-time metrics, Salt, SDDC lifecycle, the software depot and telemetry together on one platform. They run as containerized workloads in a VCF services runtime instance. The first VCF Instance hosts the fleet-level services, and every VCF Instance gets its own runtime for local tasks. Each runtime consumes addresses from a pool you define when you deploy or upgrade.
How many IP addresses VCFMS needs
| Requirement | Value (per Broadcom docs) |
|---|---|
| Minimum pool | 12 IP addresses (documented as a /28 block) |
| Recommended pool | 30 IP addresses (a /27 block), reserved for new components and scale-out |
| Network | VCF management network (9.1.0.x). A custom network via API from 9.1.1 |
| Internal runtime CIDR | 198.18.0.0/15 by default. Change it to 240.0.0.0/15 or 250.0.0.0/15 if 198.18.0.0/15 is already used in your network |
Source: First VCF Instance FQDNs and IP addresses. Plan for 30 from the start. The extra addresses are used later when you add components such as log management or real-time metrics, and growing a pool inside a crowded management VLAN is harder than reserving it up front.
IP allocation formats: CIDR, range, list, exclusions
| Format | Example | Use it when |
|---|---|---|
| CIDR | 10.0.10.224/27 | You have a clean aligned block |
| Range | 10.0.10.200 – 10.0.10.229 | You have a contiguous but unaligned free segment |
| List | 10.0.10.21, 10.0.10.37, … | The management network is fragmented |
| Exclusions | excludedAddresses | A block is mostly free but contains a few used IPs |
According to the upgrade deployment procedure, the UI accepts all these formats from VCF 9.1.0.400. On earlier 9.1 builds, the UI expects a contiguous range (new installs) or a CIDR (upgrades), and you need the API for anything else.
Where to set it: VCF Installer vs SDDC Manager
- New deployment (VCF Installer): the pool goes in the
vspClusterSpecsection of the deployment JSON (ipv4Pool). You can also enter it in the Installer UI. - Upgrade to 9.1 (SDDC Manager): VCFMS and the license server are deployed as a separate step. Use the UI, or
POST /v1/vcf-management-componentswith aVcfManagementComponentsSpecif you need non-contiguous IPs, exclusions or a custom network (xRegionNetwork, 9.1.1 and later).
API references: VCF Installer API and SDDC Manager API – vcf-management-components.
Common validation errors
- “Not all addresses from the VCF Management Services IPv4 pool are part of the management network”: part of your range or CIDR falls outside the management subnet. Shrink the block, or on 9.1.1+ use the API with a custom network (KB 440223).
- In-use IPs found in the pool: something already answers on an address in the pool. Exclude it, or move the pool. Also keep component FQDNs (vCenter, NSX, SDDC Manager, etc.) outside the runtime pool, while still on the management network.
- Overlap with 198.18.0.0/15: if your network already uses that range, change the internal runtime CIDR before deployment.
For a small lab, see deploying a minimal VCF 9.0 lab. The same rule applies there: carve out the VCFMS block before you hand out IPs to anything else.
Further reading
- William Lam: VCF 9.1 – Additional IP allocation options for VCF Management Services (VCFMS) in VCF Installer and SDDC Manager
- Broadcom TechDocs: Deploy VCF Management Services and License Server as Part of VCF Upgrade to 9.1
- Broadcom KB 440223: IPv4 pool not part of the management network
