Do You Need an ASN to Lease IPv4? Three BGP Delivery Models

An IPv4 lease and an ASN are related decisions with different jobs. The lease provides use rights for a block during an agreed term. The ASN identifies the routing policy that originates announcements. Separating those layers makes the delivery model, authorisation records, and support boundary easier to write into an Order.

The short answer

• With a provider announcing the whole /24, the customer can use the provider's Origin ASN and treat an independent ASN as optional.
• With the customer announcing through its own upstream, the customer needs a controlled ASN or an Origin ASN explicitly authorised in the Order.
• With addresses assigned to servers, a NAT pool, or cloud resources without BGP, the delivery focuses on address use and abuse handling while origin routing can remain outside the initial scope.

SKNK lists IPv4 /24 reference pricing at €450 per quarter or €1,580 per year. Availability, intended use, IP reputation, routing authorisation, and delivery boundaries are confirmed through the application and written Order. See IPv4 address leasing.

Three delivery models

Delivery model	Origin ASN	Customer-side work	Typical fit
Provider announces the /24	Provider ASN	Address assignment, host configuration, service integration	Fast address use with routing handled by an existing upstream
Customer announces through its upstream	Customer ASN or an agreed Origin ASN	BGP configuration, upstream coordination, route monitoring	A network with its own identity, upstreams, and routing policy
Address use without BGP	No separate origin arrangement	Hosts, NAT, DNS, abuse contact path	Public addresses are needed before independent routing is deployed

All three models can use the same leased block. The operational difference is who originates the announcement, who maintains route state, and who handles upstream filtering. A /24 contains 256 addresses; propagation still depends on the policies of networks along the path.

How ASN, Origin, IRR, and ROA fit together

1. Set the origin. Record the announcing prefix, Origin ASN, and the customer or designated routing provider responsible for operation.
2. Set the authority. The resource holder records the route authorisation and maintenance arrangement agreed for the case.
3. Publish routing intent. An IRR route object records the prefix and Origin ASN relationship and can feed operator filters.
4. Publish origin authorisation. A ROA records which ASN may announce which prefix and the maximum authorised prefix length.
5. Check the live state. BGP observations, RPKI validation, and IRR lookup provide separate evidence about the current setup.

IRR and ROA can be scheduled in one Order. Each record still follows the actual resource, authority source, and change path. AS-SET is a basic routing registry item and follows the customer's or designated routing provider's operational need.

Read What Is an IRR Route Object?, What Is a ROA?, and the RPKI and BGP lookup tool.

Fields to put in the Order

• Prefix: the specific /24 or the requested size under review.
• Origin: Origin ASN, expected upstream, and announcement model.
• Records: scope and maintainer for IRR route, ROA, LOA, and AS-SET.
• Operations: BGP configuration, monitoring, technical changes, and support contacts.
• Lifecycle: term, renewal, Origin changes, withdrawal, and renumbering arrangements.

Advanced topologies, additional Origin ASNs, high-volume manual work, and customer-side network engineering are assessed and quoted per case. Fees, response terms, and delivery boundaries belong in the Order.

In one sentence

Leased address use, ASN ownership, Origin authorisation, and global reachability are separate work items; choose the BGP delivery model first, then schedule IRR, ROA, LOA, and support.

Technical sources

• RIPE Database primary object documentation
• RIPE NCC RPKI and BGP Origin Validation
• IPv4 address leasing page