The IP justification form is a requirement from ARIN (American Registry for Internet Numbers) that demonstrates your legitimate need for additional IP addresses. This form is manually reviewed and regularly audited, so providing accurate, detailed information is essential to receive approval for additional IP allocations. At OBHost, we guide you through each section to ensure your request meets ARIN's strict requirements.
Understanding the IP Justification Process
ARIN oversees IP address distribution in North America and requires justification to prevent IP address exhaustion. When you request additional IPv4 addresses, you must prove that your current allocation is being efficiently used and that you have a legitimate technical need for more IPs. The form is divided into four main sections, each requiring specific information about your current and projected IP usage.
Section 1: Requested Subnet Size
Select the IP block size you need from the dropdown menu. This represents additional IPs beyond what you currently have assigned. Choose carefully based on your actual needs, as you'll need to justify every IP address in your request.
Common subnet sizes and their usable IP counts:
- /29 subnet = 8 total IPs (5 usable)
- /28 subnet = 16 total IPs (13 usable)
- /27 subnet = 32 total IPs (29 usable)
- /26 subnet = 64 total IPs (61 usable)
- /25 subnet = 128 total IPs (125 usable)
- /24 subnet = 256 total IPs (253 usable)
The difference between total and usable IPs accounts for network address, broadcast address, and gateway, which are reserved for networking purposes.
Section 2: Existing Assignments
This critical section requires complete documentation of how you're currently using every IP address already assigned to you. ARIN auditors verify that you're efficiently using your existing allocation before approving additional addresses.
For each IP address, you must provide:
- IP Address: The specific IP from your current allocation
- Customer: Full name or company name (not "customer" or generic terms)
- Usage: Specific technical reason requiring a dedicated IP
- Domain/Hostname: Associated domain or hostname when applicable
For unusable IPs (network, gateway, broadcast addresses), list "N/A" or "Not Usable" in the customer field and explain the technical reason in the usage field.
Valid Usage Examples
ARIN accepts these legitimate technical reasons for dedicated IP assignments:
- SSL/TLS certificates requiring dedicated IPs (legacy systems)
- Primary server assignments for shared hosting
- Virtual private servers (VPS) or dedicated servers
- Mail servers requiring dedicated IPs for reputation
- Network infrastructure (gateways, routers)
- Application-specific requirements that cannot use SNI or virtual hosting
Sample IP Justification Format
Here's a properly formatted example for a /29 IP block (10.1.4.0/29):
IP: 10.1.4.0
Customer: N/A
Usage: Network Address (Not Usable)
Domain/Hostname: N/A
IP: 10.1.4.1
Customer: N/A
Usage: Gateway Address
Domain/Hostname: N/A
IP: 10.1.4.2
Customer: John Smith
Usage: Primary Shared Web Hosting Server
Domain/Hostname: myserver.com
IP: 10.1.4.3
Customer: Sam James
Usage: Dedicated SSL Certificate (Legacy Application)
Domain/Hostname: customersecuresite.com
IP: 10.1.4.4
Customer: Sam James
Usage: Dedicated SSL Certificate (Legacy Application)
Domain/Hostname: anothersecuresite.com
IP: 10.1.4.5
Customer: Jane Sanders
Usage: Virtual Private Server
Domain/Hostname: vps1.myserver.com
IP: 10.1.4.6
Customer: Ben Mars
Usage: Virtual Private Server
Domain/Hostname: vps2.myserver.com
IP: 10.1.4.7
Customer: N/A
Usage: Broadcast Address (Not Usable)
Domain/Hostname: N/A
Section 3: IPs Utilized and Projected Usage
This section requires you to categorize how you'll use the additional IPs you're requesting, both immediately and in the future. If you request a /28 (16 IPs), you must account for all 16 addresses and show immediate utilization plans.
The form automatically reserves three IPs for subnetting purposes (network address, gateway, and broadcast). Your immediate utilization numbers must add up to the total IPs requested minus these three reserved addresses.
Break down your usage into categories such as:
- Dedicated servers
- Virtual private servers
- SSL certificate hosting
- Mail servers
- Application servers
- IP-based virtual hosting
- Network equipment
- Other (must explain in comments)
Provide realistic timeframes for when you'll deploy these IPs. ARIN expects immediate utilization of at least 80% of requested addresses within a few weeks.
Section 4: Comments and Remarks
Use this section to provide additional context that strengthens your justification. If you categorized IPs under "IP-based Virtual Hosting" or "Other," you must provide detailed explanations here.
Helpful information to include:
- Technical limitations preventing shared IP usage
- Business growth projections supporting your request
- Specific applications or services requiring dedicated IPs
- Timeline for deploying the requested addresses
- Any special circumstances affecting your IP needs
Be specific and technical. Vague statements like "for future growth" or "customer demand" are insufficient. Explain the technical necessity for dedicated IP addresses.
Common Reasons for IP Justification Rejection
Avoid these mistakes that commonly result in denied requests:
- Insufficient utilization of existing IPs (below 80%)
- Generic customer names like "Customer 1" or "User"
- Vague usage descriptions that don't demonstrate technical necessity
- Requesting IPs for "future use" without immediate deployment plans
- Using IPs for purposes that can be accomplished with shared IPs or SNI
- Incomplete documentation or missing required fields
- Requesting more IPs than can be justified by current and projected usage
Tips for Successful IP Justification
Follow these best practices to improve your approval chances:
- Document every IP thoroughly, including network infrastructure addresses
- Use real customer names or company names, never placeholders
- Explain technical requirements clearly and specifically
- Show immediate need for at least 80% of requested addresses
- Provide realistic deployment timelines (within 1-2 months)
- Include supporting documentation like server configurations or client lists
- Review ARIN's policies before submitting your request
- Double-check that immediate utilization numbers add up correctly
After Submitting Your IP Justification Form
Once submitted, your request enters manual review. This process typically takes several business days. Reviewers examine your justification for completeness, accuracy, and compliance with ARIN policies. If approved, the additional IP block is assigned to your account. If additional information is needed, you'll receive specific requests for clarification.
Frequently Asked Questions
How long does ARIN IP justification approval take?
Manual review typically takes 3-7 business days, though complex requests or those requiring additional information may take longer. Ensure all information is complete and accurate to avoid delays. OBHost reviews your form before submission to catch common errors.
Can I request IPs for future growth without immediate usage plans?
No. ARIN requires immediate utilization of at least 80% of requested IP addresses, typically within a few weeks. You must demonstrate specific, imminent technical needs rather than speculative future requirements. Vague "future growth" justifications are routinely rejected.
What happens if my current IPs aren't fully utilized?
ARIN expects at least 80% utilization of existing IP allocations before approving additional addresses. If your current IPs show low utilization, your request will likely be denied. Focus on efficiently using existing IPs and document legitimate technical needs for each address.
Do I need dedicated IPs for SSL certificates in modern hosting?
Modern hosting typically uses SNI (Server Name Indication), which allows multiple SSL certificates on a single IP address. However, some legacy systems, older browsers, or specific applications may still require dedicated IPs. Only cite SSL as justification if you have legitimate technical limitations preventing SNI usage.
If you need assistance completing your IP justification form or have questions about ARIN requirements, the OBHost support team is available 24/7. Contact us at https://www.obhost.net/contact or email support@obhost.org for expert guidance on your IP allocation request.
