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, CountryDate: 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::/48This 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 4567Signed,
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.