Static IP

Static vs dynamic IPs

Two main ways IP addresses get assigned to devices:

Dynamic IP (DHCP)

The DHCP server hands out IPs from a pool when devices request them. The IP can change when:

• The device reconnects after being offline.
• The DHCP lease expires (typically 24 hours to 7 days).
• The server runs out of IPs and reassigns from the pool.
• The modem reboots (for ISP-side dynamic IPs).

Default for almost all consumer internet connections and almost all LAN devices.

Static IP

The IP is fixed. Either:

• Configured on the device manually.
• The ISP guarantees the same IP for your connection.
• A DHCP reservation makes the IP appear static (server-side static).

Static IPs are stable across reboots, reconnections, and lease expirations.

Why you might need a static IP

Hosting inbound services

Any service you want other people or systems to reach by name needs DNS pointing at a stable IP. Examples:

• VPN server you connect to from outside.
• Mail server (SMTP, IMAP) — also needs reverse DNS matching the static IP.
• Web server (though hosted services are more common).
• Security cameras or NVR with remote viewing.
• Home assistant accessible from outside.
• Game servers.

SaaS IP allowlisting

Some vendors (Salesforce IP Restrictions, payroll APIs, financial integrations) only accept connections from preregistered IPs. A dynamic IP breaks this every time it changes.

VPN client IPs

Corporate VPNs that grant access based on the user's source IP after VPN connection. Less common but happens.

Email deliverability

Mail servers need consistent IP reputation. A dynamic IP that joins a residential pool inherits the pool's bad reputation; a static IP can build its own clean reputation over time.

When you do NOT need a static IP

• Pure SaaS consumer. If you only consume cloud services and never accept inbound connections, dynamic IP is fine.
• Outbound VPN client. Connecting from home to a corporate VPN doesn't need a static home IP; the corporate side has the static IP.
• Web browsing, video calls, streaming. All work fine on dynamic IPs.
• Most home services accessed via consumer apps. Hue, Ring, Nest, Apple Home all use vendor relay services that work fine behind dynamic IPs.

Costs

Residential plans usually do not offer static IPs at any price. To get a static IP, you typically must switch to a business plan, which has its own price premium.

Static IPs on LAN: DHCP reservation

For internal devices that need stable IPs (printers, NAS, port-forwarding targets, cameras), the right pattern is DHCP reservation:

1. Find the device's MAC address.
2. In the router/DHCP server, create a reservation tying that MAC to a specific IP.
3. The device continues to use DHCP normally but always receives the reserved IP.

Why this is better than configuring the IP on the device:

• Centralized management — all IP assignments visible in one place.
• Easy to change without touching the device.
• Device behavior remains correct on other networks where the reservation does not apply.
• Avoids the "device with manual IP plus DHCP server gives same IP to another device" conflict.

Use true static configuration on the device only when DHCP itself is the service being deployed (DHCP server), or when the device must work without any network services.

The CGNAT exception

Many ISPs in 2026 use CGNAT — your "public" IP is shared across many customers via NAT in the ISP's network. In this case, no static IP is meaningfully available because the visible IP is the ISP's NAT IP, not yours.

Options if you need inbound connectivity but are stuck on CGNAT:

• Request a real public IPv4 from the ISP (sometimes available as an add-on for $5-15/month).
• Use IPv6 if both endpoints support it — every IPv6 device has a globally routable address.
• Use a tunnel service (Cloudflare Tunnel, Tailscale Funnel) that establishes an outbound tunnel and exposes a public endpoint.
• Switch to an ISP that does not use CGNAT.

Alternatives to static IP

• Dynamic DNS — services like DuckDNS, No-IP, Cloudflare API auto-update DNS to your current dynamic IP. Stable hostname; the IP behind it changes.
• Cloudflare Tunnel / Tailscale — outbound tunnels that expose your service via Cloudflare or Tailscale infrastructure, no inbound connectivity required at your end.
• Hosted reverse proxy — run a small VPS with a static IP, configure your home equipment to connect outbound, the VPS forwards traffic.
• IPv6 — every IPv6 endpoint is globally addressable. Combine with dynamic DNS for IPv6 (AAAA records) to get a stable hostname.

Frequently Asked Questions

Do I need a static IP at home?

Only if you host services that need to be reached from outside — a VPN server, a security camera viewable remotely, a NAS accessible from elsewhere. Most home users do not need a static IP. Dynamic DNS services (DuckDNS, No-IP) provide a stable hostname for a dynamic IP, covering most home use cases without paying for static IP.

How much does a static IP cost?

Typically $5-30/month per static IP on a business plan. Residential plans usually do not offer static IPs at any price — you must switch to a business plan. A /29 block (5 usable IPs) typically runs $20-60/month; larger blocks scale up. The IPv4 scarcity has driven prices up over time.

What is the difference between static IP and DHCP reservation?

A true static IP is configured directly on the device — the device always uses that IP regardless of DHCP. A DHCP reservation is a server-side rule that tells the DHCP server to always hand out the same IP to a specific MAC address. From the device's perspective, the IP appears stable either way, but the configuration lives in different places. DHCP reservation is generally preferred for LAN use because it can be changed centrally; static configuration is preferred for devices that must work even when DHCP is unavailable.

Why does my SaaS vendor require a static IP?

Many SaaS vendors (Salesforce, financial APIs, healthcare integrations) implement IP allowlisting as a security control — only listed IPs can authenticate. A dynamic IP means the allowlist breaks every time your IP changes. A static IP gives the vendor a stable reference point. Alternative: many vendors now also support IP-less authentication methods (mutual TLS, OAuth, JWT) that eliminate the need for IP allowlisting.