SKNK Technical Guide
IPv4 Lease IP Reputation Checklist: What to Confirm Before Signing
A practical pre-signing checklist for an IPv4 /24 lease: block-level reputation, abuse history, reverse DNS, mail constraints, routing records, and review timestamps.
Technical content
Written and maintained by Shikanoko NetworksIPv4 reputation should be reviewed against a specific prefix, a specific intended use, and a specific point in time. A useful review record carries the block, data sources, review date, and abuse contact into the Order so it remains usable during signing, delivery, and later changes.
Six pre-signing checks
1. Record the candidate prefix
Start with the complete /24 or the requested prefix range. A supplier name or a general “clean IP” statement cannot be matched to the actual delivery resource.
2. Check public lists and abuse history
Review the addresses against relevant RBLs, abuse reports, and available historical scanning or attack signals. Record the tools used, a short result, and the timestamp. Coverage and update cycles differ across lists.
3. Confirm reverse DNS and mail use
Confirm reverse-DNS delegation, hostname format, change path, and the conditions around TCP/25, mail services, and sending reputation. Mail use is more sensitive to address history and operating behaviour, so state the plan early.
4. Compare routing and authority records
Check the Origin ASN, IRR route object, ROA, LOA, and announcement model. If the customer plans to originate the block, confirm upstream acceptance and the route-change contact. Use the RPKI and BGP lookup and IRR route-object lookup for a cross-check.
5. Write the abuse path
The Order should name the abuse contact, response channel, escalation path, suspension or isolation action, and customer cooperation steps. A concrete path makes the next action clear when a complaint arrives.
6. Define review points
Bind each result to a review date. Delivery, an Origin change, renewal, and a major use-case change can each trigger a new review so an old result is not reused as current evidence.
Suggested review record
| Field | Example |
|---|---|
| Prefix | Specific IPv4 /24 |
| Review date | 2026-09-18 |
| Sources | RBL, abuse database, rDNS, BGP, RPKI, IRR |
| Intended use | Cloud hosting, enterprise network, migration, or another use |
| Routing | Origin ASN, upstream, route, ROA, LOA |
| Abuse path | Contact, response channel, escalation, customer actions |
Reputation changes with actual use, third-party list updates, reverse DNS, and mail policy. Put the result and review points into the Order so delivery material remains current.
How this relates to price and scope
SKNK lists IPv4 /24 reference pricing at €450 per quarter or €1,580 per year. Availability, use case, IP reputation, routing authorisation, and final work scope are confirmed during the application. Reverse DNS, Geofeed, location records, Anycast, multiple origins, technical changes, and support can be customised by agreement or Order; advanced topologies, additional Origin ASNs, high-volume manual work, and customer-side network engineering are quoted per case. See the IPv4 address leasing service.
In one sentence
An IP reputation review is a traceable record rather than a single “clean” label: the prefix, sources, review date, intended use, routing authority, and abuse path all belong in the delivery evidence.