Letter of Authorization (LOA)
Once you instruct your ISP to announce a specific subnet in BGP, they will mostly request a written permission from the resource holder (usually a LIR). This permission is called Letter of Authorization (LOA).
Below is an example for such a LOA:
Authorization to Announce IP Space
To Whom It May Concern,
this letter serves as authorization for Company, Inc.1 with AS987652 to advertise the following IP address block:
127.0.0.1/243
As a representative of LIR, Inc.4, the owner of the above subnet, I hereby declare that I'm authorized to represent and sign this Letter of Authorization.
This authorization shall remain in effect until revoked or modified in writing.
Sincerely,
nosreteP .F nhoJ
(Chief Executive Officer)5