IP Rental — IPv4 Range Rental

rDNS and routing

You can set reverse DNS (rDNS) records for the addresses you rent, which is effectively mandatory for mail servers. Addresses are managed from the customer panel, where you can configure routing and rDNS yourself.

Usage rules

Rented addresses are allocated in Datafex's name and you are responsible for how they are used. Spam, malware distribution and use as a source of attacks lead to suspension. These rules exist to protect the reputation of the address; a blacklisted range affects whoever uses it next as well.

Range size: how many addresses a /29 really gives you

IPv4 ranges are split in powers of two, and in every routed block three addresses go straight away: the network address, the broadcast address and the gateway. In practice the usable count works out as follows — 1 of 4 addresses in a /30, 5 of 8 in a /29, 13 of 16 in a /28 and 253 of 256 in a /24. So I bought eight IPs does not mean you can run eight separate services; account for those three from the start. A second common misconception is that every domain needs its own IP: thanks to SNI, hundreds of domains and certificates run fine on a single address. What genuinely needs a separate address is a short list — a mail server that needs its own rDNS record, game server instances listening on their own ports, and VPN or integration clients that need a distinct outbound address.

IP reputation: why no two addresses are alike

An IPv4 address may not have been allocated to you first; in this world addresses change hands and past usage sticks to them. If you send mail, that shows up directly in your delivery rate: mail from an address flagged on reputation lists is either rejected or lands in spam. When you start sending from a new address, do three things. First, the records: define SPF, DKIM and DMARC for your domain, and make the reverse DNS (rDNS) record match the name the server introduces itself with in the SMTP session, because most receiving servers check that consistency. Second, volume: do not start at high volume, ramp up gradually — a sudden spike is the fastest way to get a new address flagged. Third, monitoring: check the address against blacklist lookup tools regularly, because once you are on a list, getting off it runs through a request you have to file.

Why IPv4 is scarce, and why we ask what it is for

The IPv4 address space is capped at 4.3 billion addresses and that pool is gone. RIPE NCC, which serves the European region, announced on 25 November 2019 that its free IPv4 pool had run out; since then allocations come only from returned addresses and a waiting list, at a maximum size of /24. That is why a request for extra IPs is not a stock question but an allocation decision: you are asked how many addresses you need and for which service, and the justification is assessed. For the same reason idle ranges are reclaimed — an unused address can go to a project that needs it. There is no such scarcity on the IPv6 side; if your project supports IPv6, address count stops being a constraint and a dual-stack setup markedly reduces how much IPv4 you need.

How the process works

1. 1Write down the need: how many separate addresses, for which services and on which server.
2. 2Choose the range size, remembering that the usable count is three fewer than the block size.
3. 3Once allocated, add the addresses to your server's network configuration.
4. 4Enter reverse DNS (rDNS) records from the panel where you need them.
5. 5If you will send mail: complete SPF, DKIM and DMARC records and ramp sending volume up gradually.
6. 6Check the addresses against blacklists regularly; a listing spotted early is easier to reverse.

Common mistakes

• Assuming usable addresses equal the block size. In a /29, five of the eight addresses remain usable.
• Buying a separate IP for every domain. SNI runs hundreds of certificates on one address; a separate address is only needed for services that genuinely require their own.
• Sending mail without rDNS. A significant share of receiving servers reject senders with no reverse record, or one that does not match the HELO name.
• Sending at high volume from a new address on day one. Starting without a gradual ramp is the fastest way to get the address flagged.
• Leaving addresses idle. An unused range weakens the justification for the allocation and can be reclaimed.

Frequently Asked Questions

How many IPs can I rent?

Sizes from a single address up to a /24 range are possible. The number you request and its intended use are assessed; because IPv4 is scarce, allocation depends on justification.

Is IPv6 available?

Unlike IPv4, IPv6 allocation is not scarce and can be provided on request. If your project supports IPv6 it is also the cheaper option.

I rented a /29 — how many services can I run?

Five. Of the eight addresses, one is the network address, one the broadcast address and one the gateway. If you need more services, plan for a /28 (13 usable) or larger.

Does every domain need its own IP?

No. SNI allows different SSL certificates to be served for different domains on the same IP address, so hundreds of sites can share one. A separate address is needed for services that require their own rDNS record or their own outbound address.

What happens if my address gets blacklisted?

Filing for delisting is yours as the party using the address, and the cause of the listing has to be fixed first. That is why sending practices appear as rules in the agreement: a blacklisted range also affects whichever customer uses that address after you.

Can I use a rented address on a server at another provider?

Rented addresses are announced through the Datafex network, so by default they are used on services here. Carrying them to a server in another location requires the traffic to be tunnelled, which falls under the setup described on the BGP protection page.