Updated: 28 September 2026 · Applies to: Self-managed dedicated servers, additional IPv4 blocks /28 to /24

If the IP addresses that come with your dedicated server are not enough (many plans include 1 usable IPv4, some include 5), you can add an additional subnet: /29 (5 usable), /28 (13), /27 (29), /26 (61), /25 (125) or /24 (253). Ucartz also processes custom requests, for example 5 usable addresses taken from 5 different subnets. This guide shows what to prepare, how to ask, and what to do when the block is delivered.

Before you ask

  1. Decide how many addresses you need (see How many IP addresses do you need for your dedicated server?) and choose the smallest block that leaves a reserve. Sizes and usable counts are listed in How many IP addresses come with a dedicated server and what do additional subnets cost?.
  2. Note the service ID or main IP address of the dedicated server that will receive the block. Additional IP blocks belong to one server.
  3. Know what you will use the addresses for. This helps support to advise the right block and is checked if a block is later removed.
  4. Remember that a delivered server stays in its data centre, and blocks are tied to that location (Ucartz dedicated server locations, IP address rules and additional IP support).

What it costs

Additional blocks are priced per month. The Ucartz cart shows, in US dollars per month (September 2026): additional /29 about 10 to 30 depending on the server and the request, /28 60, /27 136, /26 172, /25 331 and /24 512. Not every server model offers every block in the cart, and custom requests are quoted. The details are in How many IP addresses come with a dedicated server and what do additional subnets cost?. Choose the block in the cart when you order the server if it is offered there, or ask in a ticket as described below.

How to request the subnet

  1. Log in to the client area and open a ticket at Support › Submit a Ticket.
  2. Write the request in one message, for example:
    Subject: Additional IPv4 subnet for server 203.0.113.10

Please add a /26 subnet (61 usable IPv4) to my dedicated server
203.0.113.10 (service ID 12345).
Purpose: virtual machines and separate web applications.
Please send the price and the network details (network, netmask
and gateway of the block).
  3. Support answers with the price and whether the block can be added at your server's location. Pay the invoice.
  4. When the block is added you receive its network details: the network address, the netmask and the gateway of the block. Every additional subnet has its own gateway. Keep this message; you need it to configure the addresses.

Custom orders: addresses from several different subnets

Some customers do not need one large block. They ask for a few addresses from several different subnets, for example 5 usable addresses from 5 different subnets, to keep each address in a different network. Ucartz processes such orders too. They need extra work on the network side and on your server, because each subnet has its own gateway:

After the block is delivered

  1. Configure the addresses and the block's gateway on the server: How to add additional IPv4 addresses on Ubuntu with netplan? (Ubuntu), How to add additional IPv4 addresses on AlmaLinux or Rocky Linux with nmcli? (AlmaLinux and Rocky Linux) or How to add additional IPv4 addresses on Windows Server? (Windows Server).
  2. Test every address: How to test that every additional IP address works on your server?.
  3. Set reverse DNS for the addresses that will send mail or need a proper name: How to set reverse DNS (PTR) for many IP addresses and check forward-confirmed rDNS?.
  4. Check a new block against public blocklists before you put services on it: How to check whether a new IP address is on a blocklist before you use it?.

Good to know

  • You cannot exchange single addresses of a delivered block for other ones, because IP addresses are final after delivery. Custom mixes of subnets are arranged before delivery, in the ticket.
  • Free Basic Managed Support helps with quick checks (best effort). Larger network work can be booked by the task or by the hour.

Frequently asked questions

Can I get several small blocks instead of one big one?
Yes, ask in the ticket. One larger block is usually easier to manage (one gateway, one routing table); several blocks or subnets mean one table for each.

Can I move a block to my other server?
Ucartz does not move IP addresses between servers. Order the block for the server that will use it.

See also the knowledge base article Dedicated Server's with additional IPv4.

Need a dedicated server, more IP addresses, or a hand with the setup?

Prefer a hand with the setup? Our engineers can do it for you: Hire an Expert, or use our on-demand server management.

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