BuyIPv4.com

Author: BuyIPv4.com

  • How to Bring Your Own IPs (BYOIP) to Google Cloud Platform

    Coming soon…

  • What is Reverse DNS Delegation?

    Introduction

    Most people are familiar with DNS translating domain names into IP addresses. Reverse DNS does the opposite. Reverse DNS delegation plays a critical role in email delivery, security validation, and network trust. This article explains reverse DNS delegation in clear and practical terms.

    What Is Reverse DNS?

    Reverse DNS, also known as rDNS, resolves an IP address to a domain name. It uses special DNS zones under in-addr.arpa for IPv4 and ip6.arpa for IPv6.

    Instead of asking which IP belongs to a domain, reverse DNS answers which domain belongs to an IP address.

    What Is Reverse DNS Delegation?

    Reverse DNS delegation is the process of assigning control of reverse DNS records for an IP range to another party. Typically, an IP address owner delegates reverse DNS management to a hosting provider or customer.

    How Reverse DNS Delegation Works

    PTR Records

    Reverse DNS uses PTR records to map an IP address to a fully qualified domain name.

    Delegation via Name Servers

    The IP address owner configures name server records at the RIR or upstream provider level, pointing reverse DNS control to the delegated party’s DNS servers.

    Customer Management

    Once delegated, the customer can create and manage PTR records independently.

    Why Reverse DNS Is Important

    Email Deliverability

    Mail servers often reject or score down email sent from IP addresses without valid reverse DNS entries.

    Security and Trust

    Reverse DNS helps verify the legitimacy of servers and reduces spoofing risks.

    Logging and Monitoring

    Readable hostnames improve clarity in logs and network diagnostics.

    Reverse DNS for IPv4 and IPv6

    IPv4 Reverse DNS

    IPv4 reverse DNS uses the in-addr.arpa domain with octets reversed.

    IPv6 Reverse DNS

    IPv6 reverse DNS uses the ip6.arpa domain with hexadecimal digits reversed, making delegation more granular but also more complex.

    Common Reverse DNS Delegation Scenarios

    Hosting Providers

    Providers delegate reverse DNS to customers running mail or application servers.

    BYOIP Environments

    Organizations using BYOIP often require reverse DNS delegation to maintain full control.

    Conclusion

    Reverse DNS delegation is a foundational networking feature that directly impacts email reliability, security posture, and operational clarity. Properly configured reverse DNS is essential for any organization operating internet-facing services.

  • What is the Border Gateway Protocol (BGP)?

    Introduction

    The internet is not a single network but a collection of thousands of independent networks. The protocol that allows these networks to exchange routing information is the Border Gateway Protocol, or BGP. This article explains BGP in a practical and accessible way.

    What Is the Border Gateway Protocol?

    BGP is the routing protocol used to exchange routing information between autonomous systems on the internet. An autonomous system is a network or group of networks managed by a single organization and identified by an Autonomous System Number (ASN).

    How BGP Works

    Route Advertisement

    Networks advertise the IP prefixes they can reach to neighboring autonomous systems.

    Path Selection

    BGP evaluates multiple available paths and selects the best route based on policies, not speed.

    Policy-Based Routing

    Unlike interior routing protocols, BGP decisions are influenced by business relationships, cost, and traffic engineering goals.

    Key BGP Concepts

    Autonomous System Number

    Each BGP-speaking network is identified by a unique ASN.

    IP Prefixes

    BGP announces routes as IP prefixes, such as IPv4 or IPv6 networks.

    Peering and Transit

    BGP sessions are established between networks for peering or transit relationships.

    Why BGP Is Important

    Internet Scalability

    BGP allows the internet to scale by distributing routing decisions.

    Traffic Engineering

    Organizations can control inbound and outbound traffic flows.

    Redundancy and Resilience

    Multiple BGP paths enable failover and high availability.

    Common Use Cases for BGP

    Internet Service Providers

    ISPs rely on BGP to exchange routes globally.

    Data Centers and Cloud Providers

    BGP is used for redundancy and multi-homing.

    BYOIP Deployments

    BGP is required to announce customer-owned IP addresses.

    Conclusion

    The Border Gateway Protocol is the backbone of the internet’s routing system. While complex, it provides unmatched flexibility and control for organizations that need resilient and scalable connectivity.

  • What Is Bring Your Own IP (BYOIP)? A Complete Guide for Businesses

    Introduction

    As organizations move workloads between data centers, cloud providers, and hosting environments, IP address portability becomes increasingly important. Bring Your Own IP, commonly abbreviated as BYOIP, solves a key problem: maintaining control over your IP addresses regardless of where your infrastructure runs. This article explains what BYOIP is, how it works, and why businesses choose it.

    What Is Bring Your Own IP (BYOIP)?

    Bring Your Own IP is a networking model that allows an organization to use its own publicly registered IP address ranges with third-party service providers, such as cloud platforms, hosting companies, or connectivity providers. Instead of using IP addresses assigned by the provider, the customer retains ownership and control of the IP space.

    These IP addresses are typically allocated by a Regional Internet Registry (RIR) such as RIPE NCC, ARIN, or APNIC.

    How BYOIP Works

    IP Address Ownership

    The organization must own a public IP address block registered with an RIR. This block remains assigned to the organization, not the service provider.

    Provider Authorization

    The organization authorizes the provider to announce the IP range on its behalf. This is usually done using a Letter of Authorization (LoA).

    BGP Announcement

    The service provider advertises the IP range to the global internet using the Border Gateway Protocol (BGP). Traffic destined for the IP addresses is routed to the provider’s infrastructure.

    Routing Control

    The customer can move the IP range between providers by changing BGP announcements, allowing flexibility without renumbering systems.

    Benefits of BYOIP

    Provider Independence

    BYOIP prevents vendor lock-in. IP addresses can be moved between cloud providers or data centers without changing DNS records or reconfiguring applications.

    Improved Reputation Management

    IP reputation, especially for email delivery and security-sensitive applications, stays with the organization rather than the provider.

    Business Continuity

    In disaster recovery scenarios, workloads can be migrated while keeping the same IP addresses reachable.

    Regulatory and Compliance Advantages

    Some industries require long-term ownership of network resources. BYOIP supports compliance by keeping IP assets under organizational control.

    Common Use Cases for BYOIP

    Cloud Migrations

    Organizations moving from on-premises to cloud environments use BYOIP to avoid service disruptions.

    Multi-Cloud Architectures

    BYOIP simplifies routing and identity management across multiple providers.

    High-Availability Designs

    IP ranges can be dynamically moved between locations for redundancy.

    Challenges and Considerations

    Provider Support

    Not all providers support BYOIP, and requirements may differ.

    Routing Complexity

    Managing BGP and routing policies requires networking expertise.

    Minimum IP Block Sizes

    Providers often require a minimum prefix length, such as a /24 for IPv4.

    Conclusion

    Bring Your Own IP is a powerful solution for organizations that need flexibility, control, and long-term stability of their IP addresses. While it introduces additional routing complexity, the benefits often outweigh the operational overhead for growing and cloud-focused businesses.

  • How to Bring Your Own IPs (BYOIP) to Vultr

    Coming soon…

  • How to Bring Your Own IPs (BYOIP) to OVHcloud

    Introduction: What Is BYOIP at OVHcloud?

    Bring Your Own IP (BYOIP) is a feature from OVHcloud that allows organizations to use IPv4 address ranges they already own directly on the OVHcloud network. Instead of relying solely on OVHcloud-assigned IP addresses, you can import your own public IP ranges and use them as Additional IPs across supported OVHcloud services.

    This approach is particularly useful for companies that want long-term IP portability, consistent IP reputation, and greater control over routing and network architecture.

    What Is Bring Your Own IP (BYOIP)?

    BYOIP allows you to import an existing IPv4 range into OVHcloud and have it announced from their infrastructure using Border Gateway Protocol (BGP). Once imported, the IP range behaves like a standard OVHcloud Additional IP product.

    When importing a bigger range than a /24, it is internally split up into /24 blocks, usable within a single OVHcloud region, and managed through the OVHcloud Control Panel or API. Announcement of the IP range starts once a /24 block, or part thereof, is assigned to an eligible service.

    BYOIP Requirements at OVHcloud

    Before ordering the BYOIP service, several technical and administrative requirements must be met to ensure successful delivery and stable routing.

    Supported Regional Internet Registries (RIRs)

    OVHcloud currently supports IPv4 ranges registered with the following Regional Internet Registries:

    • ARIN
    • RIPE NCC
    • APNIC (support for National Internet Registries is experimental)

    The WHOIS record for the IPv4 block must exactly match the imported range. Selecting a parent or child block will prevent the range from being used.

    IP blocks from ARIN, RIPE, or APNIC can now be used in any OVHcloud region, removing earlier geographical restrictions.

    Accepted IP Block Sizes

    OVHcloud accepts IPv4 ranges from size /24 up to /19. Larger ranges are split into multiple /24 blocks during the import process.

    A /24 results in one block, while a /19 results in thirty-two /24 blocks. Ranges smaller than /24 or larger than /19 are not supported at launch.

    Valid Ownership Status per RIR

    The imported IP range must have a valid ownership status depending on the RIR.

    For ARIN, supported types include Direct Allocation, Direct Assignment, Reallocated, and Reassigned.

    For RIPE NCC, supported statuses include ALLOCATED PA, LIR-PARTITIONED PA, SUB-ALLOCATED PA, ASSIGNED PA, ASSIGNED PI, and LEGACY.

    For APNIC, supported statuses include Allocated-Portable, Allocated-Non-Portable, Assigned-Portable, and Assigned-Non-Portable.

    Choosing an OVHcloud Region

    During the order process, you must select one OVHcloud region where your IP range will be used. Once delivery is complete, /24 blocks can be moved between services within the same region.

    It is not possible to change the region of an imported IP range after delivery, where the Gravelines, Roubaix, and Strasbourg regions are regarded as one French region.

    Proving Ownership of the IP Range

    To verify ownership of the IP range, OVHcloud provides a unique verification token that must be added to the public WHOIS object before placing the order.

    For RIPE, the token must be added to the descr field of the inetnum object.
    For ARIN, it must be added to the Public Comments field of the Network object.
    For APNIC, it must be added to the remarks field of the inetnum object.

    The token must appear on its own dedicated line and must remain in place until the delivery process is complete.

    Proving Ownership of an AS Number

    If you choose to provide your own AS number, ownership must be verified using the same token used for the IP range.

    For RIPE, the token must be placed in the descr field of the aut-num object.
    For ARIN, it must be placed in the Public Comments field of the ASN object.
    For APNIC, it must be placed in the remarks field of the aut-num object.

    Allowing OVHcloud to Announce the IP Range

    You must create a route object for the IP range in the RIR where it is registered. The route object must exactly match the imported IP range and specify either OVHcloud AS16276 or your own AS number as the origin.

    If the IP range is already announced from another provider, routing conflicts or packet loss may occur. In such cases, OVHcloud cannot guarantee connectivity to OVHcloud services.

    How BYOIP Works After Delivery

    Once delivered, imported IP ranges behave like their regular Additional IP products. Each imported range is split into /24 blocks that can be assigned to eligible services within the selected region.

    Announcement of the IP range on the Internet begins when at least one /24 block is assigned to a compatible service.

    Some limitations apply. WHOIS records cannot be modified through the OVHcloud Control Panel or API, and reverse DNS handling is restricted. OVHcloud creates ARPA zones during delivery, and reverse DNS changes become publicly visible once the RIR delegates the zone.

    IP Range Slicing and Aggregation

    Imported IP blocks can be further split into smaller blocks or individual IP addresses through either the OVHcloud API or their Manager.

    Slicing an IP Block

    To slice a block, it must be unused and have no pending operations. The slicing process is asynchronous, and the resulting blocks behave like standard Additional IP products.

    Aggregating IP Blocks

    Aggregation allows smaller blocks to be merged back into a parent block. This operation is asynchronous and requires all child blocks to be available.

    Conclusion

    OVHcloud’s Bring Your Own IP feature enables organizations to use their existing IPv4 resources on a global cloud platform while retaining control over routing and IP reputation. With support for major RIRs, flexible region usage, and API-driven management, BYOIP is well suited for enterprises, ISPs, and SaaS providers.

    Proper preparation is essential, particularly when it comes to WHOIS records, route objects, and reputation checks. When configured correctly, BYOIP offers long-term IP portability without sacrificing network stability or performance.

  • How to Bring Your Own IPs (BYOIP) to Amazon Web Services (AWS)

    Coming soon…

  • Leasing IPv4 Versus Becoming a RIPE NCC Member, Cost, Control, and Long Term Strategy

    Introduction, IPv4 Scarcity Requires Strategic Decisions

    IPv4 address exhaustion has fundamentally changed how organizations acquire public IP address space. Where IPv4 addresses were once assigned directly and quickly, today companies must carefully choose between leasing IPv4 space or becoming a RIPE NCC member to request allocations themselves.

    At first glance, RIPE NCC membership may appear attractive due to direct control and long term ownership. However, once membership fees, waiting lists, and upfront sunk costs are taken into account, leasing IPv4 often proves to be the more practical and economical choice, especially for smaller deployments.

    This article compares leasing a /24 IPv4 block with becoming a RIPE NCC member, focusing on cost, timing, control, and long term strategic considerations.

    What Is RIPE NCC Membership

    The Role of RIPE NCC

    RIPE NCC is the Regional Internet Registry responsible for managing IP address space in Europe, the Middle East, and parts of Central Asia. Organizations that become members, also known as Local Internet Registries, can request IPv4 and IPv6 resources directly from RIPE NCC.

    Membership allows organizations to manage their own address space, configure routing security, and maintain full autonomy over their internet number resources.

    RIPE NCC Membership Costs

    Under the current RIPE NCC Charging Scheme, becoming a member involves the following costs:

    • a one time sign up fee of 1,000 euros
    • an annual membership fee of 1,800 euros

    To receive an initial IPv4 /24 allocation, new members must first join the IPv4 waiting list. During this waiting period, the organization must remain an active paying member.

    The waiting time is typically around two years, during which no IPv4 address space is usable.

    Total Cost to Obtain the First /24

    Over the first two years, the total cost is:

    • year one membership fee, 1,800 euros
    • year two membership fee, 1,800 euros
    • one time setup fee, 1,000 euros

    This results in a total of 4,600 euros paid before receiving the first /24 IPv4 block.

    After the allocation is received, the organization continues paying 1,800 euros per year to retain membership and keep the address space, subject to future changes in RIPE NCC billing schemes.

    This makes the initial cost a sunk investment with delayed return.

    Leasing IPv4 Address Space

    How IPv4 Leasing Works

    IPv4 leasing allows organizations to rent address space from providers that already hold IPv4 allocations. The addresses are routed to the customer and can be used immediately, without becoming a RIPE NCC member.

    A typical market price for leasing a /24 IPv4 block is:

    • 119 euros per month
    • 1,428 euros per year

    There are no setup fees, no waiting lists, and no long term contractual obligations in most cases.

    Cost Comparison Between Leasing and Membership

    For a single /24 IPv4 block, the cost comparison looks as follows:

    • RIPE NCC membership costs 4,600 euros over the first two years, with no usable IPv4 during the waiting period
    • IPv4 leasing costs 2,856 euros over two years, with immediate usability

    After the waiting period, RIPE NCC membership continues to cost 1,800 euros per year, while leasing remains at approximately 1,428 euros per year.

    From a purely financial perspective, leasing remains cheaper for at least the first several years.

    Operational Control and Flexibility

    Benefits of RIPE NCC Membership

    RIPE NCC membership provides:

    • full administrative control over IP address space
    • direct access to RIPE database management
    • native RPKI and routing policy control
    • independence from third party leasing providers

    This level of control is particularly valuable for internet service providers, network operators, and organizations with strict routing or compliance requirements.

    Advantages of Leasing IPv4

    Leasing IPv4 offers:

    • immediate availability of address space
    • lower upfront costs
    • predictable monthly expenses
    • flexibility to scale up or down

    For hosting companies, SaaS platforms, startups, and short term projects, leasing aligns well with operational and financial flexibility.

    IPv6 as a Strategic Factor

    IPv6 Allocation Through RIPE NCC

    An important advantage of RIPE NCC membership is access to IPv6 address space. Members can request an IPv6 allocation, typically ranging from a /29 to a /32.

    There is no additional cost for IPv6 allocation, no waiting list, and no need to lease IPv6 separately.

    For organizations deploying IPv6 or planning a transition, this can significantly improve the overall value of membership.

    When RIPE NCC Membership Makes Sense

    Becoming a RIPE NCC member is generally justified when one or more of the following apply.

    Full and Permanent Control Is Required

    Membership is suitable if you need:

    • complete ownership and control of IP resources
    • long term routing stability
    • independence from commercial leasing arrangements

    Native IPv6 Is a Priority

    If your infrastructure requires:

    • permanent IPv6 address space
    • no recurring IPv6 leasing costs
    • direct resource management

    RIPE NCC membership becomes more attractive.

    Multiple IPv4 /24 Blocks Are Involved

    Membership can also make sense if you are acquiring multiple IPv4 /24 blocks via the transfer market. In this case, the annual membership fee is spread across more address space, lowering the effective recurring cost per /24.

    This does require a higher upfront investment, but can be cost efficient for larger operators.

    When Leasing IPv4 Is the Better Option

    Leasing IPv4 is usually the better choice if you:

    • only need one or a small number of /24 blocks
    • require immediate deployment
    • want to avoid large upfront costs
    • operate in a dynamic or short term environment

    For many organizations, leasing remains the most economical and operationally simple solution.

    Conclusion, Choosing the Right Strategy

    The decision between leasing IPv4 and becoming a RIPE NCC member should be based on strategy rather than sentiment.

    Leasing IPv4 offers speed, flexibility, and lower short to medium term costs. RIPE NCC membership offers autonomy, native IPv6, and scalability, but requires a significant upfront investment and patience.

    For a single /24 IPv4 block, leasing is usually the rational choice. For long term growth, IPv6 adoption, or ownership of multiple IPv4 blocks, RIPE NCC membership can become strategically sound.

    Aligning your choice with your technical needs and financial horizon is the key to making IPv4 scarcity work in your favor.

  • Buying vs Leasing IPv4 Addresses: Cost, Strategy, and Future Outlook

    Introduction

    IPv4 addresses have become a scarce and valuable resource. While IPv6 adoption continues, many businesses still depend on IPv4 for compatibility and reachability. Organizations such as hosting providers, cloud platforms, ISPs, and SaaS companies must therefore decide how to obtain IPv4 space: by buying address blocks on the secondary market or by leasing them on a monthly basis.

    Both approaches have advantages and trade-offs. The right choice depends on cost, flexibility, expected duration of use, and risk tolerance. This article compares buying versus leasing IPv4 addresses, explains the role of RIRs and the aftermarket, and helps determine which strategy makes sense in different situations.

    IPv4 Availability at the RIRs

    Contrary to popular belief, Regional Internet Registries still distribute IPv4 addresses, but availability is extremely limited and subject to strict conditions.

    RIPE NCC IPv4 Waiting List

    RIPE NCC operates an IPv4 waiting list, where Local Internet Registries can apply for a single /24 allocation.

    As of 29 January, there are 744 LIRs waiting for a /24 block, and the first applicant has already been waiting 449 days, well over a year.

    More details can be found here:
    https://www.ripe.net/manage-ips-and-asns/ipv4/ipv4-waiting-list/

    This makes RIPE allocations unsuitable for organizations that need IPv4 space quickly or in larger quantities.

    ARIN IPv4 Waiting List

    ARIN also maintains an IPv4 waiting list with periodic distributions based on returned address space.

    Information about the ARIN waiting list is available here:
    https://www.arin.net/resources/guide/ipv4/waiting_list/

    While ARIN continues to distribute IPv4 blocks, availability is unpredictable and often insufficient for growing demand.

    APNIC IPv4 Availability

    APNIC still has IPv4 supply available, but allocations are capped at a maximum of a /23 per organization.

    Details can be found here:
    https://help.apnic.net/s/article/Obtaining-resources

    For organizations requiring more address space, this limitation quickly becomes a blocker.

    The Aftermarket Reality

    If you need more IPv4 addresses than the RIRs can provide, or if you need them quickly, you are effectively bound to work with the IPv4 aftermarket, either through purchases or leases.

    Buying IPv4 Addresses

    What Buying IPv4 Means

    Buying IPv4 addresses means acquiring the long-term rights to use an address block via a transfer recorded in the relevant RIR database. While IPv4 addresses are often treated as assets, it is important to note that they are not technically owned. The RIR retains ultimate authority and can revoke or reclaim resources under certain conditions.

    Buying does, however, provide durable usage rights and administrative control for as long as the registration remains valid.

    More details are available on our Buy IPv4 page.

    Cost of Buying IPv4

    At current market rates, IPv4 addresses typically sell for around 26 euros per IP.

    A /24 block with 256 addresses therefore costs approximately:

    256 × 26 euros = 6,656 euros

    Pricing transparency can be observed through public marketplaces and brokers such as:

    This is a one-time capital expense, excluding transfer fees and possible RIR-related costs.

    Advantages of Buying IPv4

    Buying IPv4 provides long-term stability, full administrative control, and predictable costs over time. It is often preferred by organizations with permanent IPv4 requirements and a clear long-term infrastructure strategy.

    Disadvantages of Buying IPv4

    The primary disadvantages are the high upfront cost, reduced flexibility, and capital being tied up in address space. Buying also exposes organizations to long-term market and regulatory uncertainty, including policy changes by RIRs.

    Leasing IPv4 Addresses

    What IPv4 Leasing Is

    Leasing IPv4 addresses means paying a monthly fee to use IP space held by another party. The lessee is authorized to announce and use the addresses, but does not hold the long-term registration rights.

    More information can be found on our Lease IPv4 page. We can also assist customers directly in obtaining a lease contract and securing a suitable IPv4 block for their use case.

    Cost of Leasing IPv4

    Leasing IPv4 is generally more cost-efficient in the short to medium term.

    Typical market rates range from 90 to 150 euros per month per /24. A commonly seen rate is around 119 euros per month.

    At 119 euros per month, the annual cost is 1,428 euros. Compared to a purchase price of 6,656 euros, the break-even point is reached after approximately 56 months:

    6,656 ÷ 119 ≈ 55.9 months

    This means leasing remains the cheaper option for nearly five years.

    Advantages of Leasing IPv4

    Leasing requires no upfront investment, allows rapid scaling, and provides flexibility when demand is uncertain. It is often the most cost-optimized approach for growing companies or temporary projects.

    Disadvantages of Leasing IPv4

    Leasing involves ongoing operational expenses and does not create long-term usage rights. Over extended periods, total lease costs can exceed the cost of buying. Lease continuity also depends on the stability of the lessor and the contract terms.

    Buying vs Leasing IPv4: Cost Comparison

    Break-Even Considerations

    With current market pricing, buying IPv4 only becomes financially advantageous after roughly four to five years of uninterrupted use.

    If IPv4 space is required for a shorter period, leasing is typically the more economical and flexible option. For long-term, predictable usage, buying can reduce total cost over time.

    Strategic Considerations: Which Option Makes Sense When

    When Buying IPv4 Makes Sense

    Buying IPv4 is generally suitable when address requirements are stable and long-term, when administrative control is critical, and when IPv4 is viewed as a strategic infrastructure resource. This is common among ISPs, network operators, and established hosting providers.

    When Leasing IPv4 Makes Sense

    Leasing IPv4 is often the better choice when minimizing upfront cost is important, when demand is temporary or uncertain, or when rapid scaling is required. Startups, SaaS platforms, and fast-growing environments typically benefit most from leasing.

    IPv4 Marketplaces and Third-Party Platforms

    Marketplaces such as IPXO and InterLIR provide platforms for leasing IPv4 address space through intermediaries.

    While these marketplaces can be convenient, it is important to understand that you are often not contracting directly with the registered holder of the IP space. This can introduce uncertainty around lease duration, renewals, and long-term stability.

    For mission-critical infrastructure, direct lease agreements with the address holder usually provide greater clarity and reliability.

    The Future Outlook for IPv4

    IPv4 Scarcity and Pricing

    IPv4 scarcity is expected to persist. Prices on the aftermarket are unlikely to decline significantly, and demand for leased IPv4 space remains strong. IPv4 continues to be necessary for compatibility with legacy systems and large parts of the global internet.

    IPv6 and Dual-Stack Reality

    Most networks will continue operating in a dual-stack environment for the foreseeable future. IPv4 will remain relevant for many years, even as IPv6 adoption gradually increases.

    Conclusion

    There is no universal answer to whether buying or leasing IPv4 addresses is the better choice.

    Leasing IPv4 is typically the most cost-optimized and flexible solution in the short to medium term. Buying IPv4 becomes more attractive for organizations with long-term, stable requirements and a strategic need for durable usage rights.

    Many organizations ultimately adopt a hybrid strategy, leasing IPv4 to support growth while selectively acquiring address space to secure long-term capacity.

  • What is a Letter of Authorization (LoA)?

    Introduction

    In networking and telecommunications, formal authorization is often required to allow another party to manage or announce your resources. A Letter of Authorization, commonly called an LoA, provides this permission in a standardized and verifiable way.

    What Is a Letter of Authorization?

    A Letter of Authorization is a formal document in which a resource owner grants permission to another party to perform specific actions. In networking, this usually involves IP address announcements, routing, or DNS delegation.

    When Is an LoA Required?

    IP Address Announcements

    When a provider announces your IP addresses using BGP.

    BYOIP Configurations

    To authorize cloud or hosting providers to use your IP space.

    Reverse DNS Delegation

    Some providers require an LoA before delegating reverse DNS control.

    What Information an LoA Contains

    Resource Details

    IP address ranges or AS numbers covered by the authorization.

    Authorized Party

    The organization receiving permission.

    Scope and Purpose

    What actions are allowed, such as BGP announcements.

    Validity Period

    Start and end dates of the authorization.

    Signature and Contact Information

    Proof that the request comes from the legitimate resource owner.

    Example of a Letter of Authorization

    Company Name: Example Networks Ltd
    Registered Address: Example Street 1, 1234 AB City, Country

    Date: 15 January 2026

    Subject: Letter of Authorization for IP Address Announcement

    We, Example Networks Ltd, hereby authorize Hosting Provider B.V. to announce the following IP address ranges on our behalf:

    IPv4: 203.0.113.0/24
    IPv6: 2001:db8:1234::/48

    This authorization is valid solely for the purpose of BGP announcement and related routing activities.

    Authorization is valid from 15 January 2026 until 15 January 2027.

    If you have any questions regarding this authorization, please contact:

    Name: John Doe
    Email: noc@example-networks.com
    Phone: +31 10 123 4567

    Signed,
    John Doe
    Network Operations Manager
    Example Networks Ltd

    Conclusion

    A Letter of Authorization is a simple but critical document that enables cooperation between IP address owners and service providers. Clear, well-defined LoAs reduce delays, prevent disputes, and ensure smooth network operations.