# Access Control

Source: https://docs.sliplane.io/services/access-control

Learn how to limit access to your services

Use an IP allowlist to restrict connections to TCP or UDP services.

## How It Works

When you add one or more allowlist rules to a service, only traffic from the specified IP addresses or subnets is allowed. All other traffic is blocked.

If no rules are configured, the service is open to all traffic (default behavior).

## Adding a Rule

1. Navigate to your service settings
2. Find the **Access Control** section
3. Click **Add Rule**
4. Enter an IP address or CIDR range
5. Optionally add a comment to describe the rule (e.g. "Office VPN" or "CI server")

## CIDR Notation

Rules use [CIDR notation](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing) to specify IP ranges, for both IPv4 and IPv6:

| Rule             | What it matches                                           |
| ---------------- | --------------------------------------------------------- |
| `203.0.113.10`   | A single IPv4 address                                     |
| `203.0.113.0/24` | All IPs from 203.0.113.0 to 203.0.113.255 (256 addresses) |
| `0.0.0.0/0`      | All IPv4 addresses                                        |
| `2001:db8::1`    | A single IPv6 address                                     |
| `2001:db8::/48`  | An IPv6 range                                             |
| `::/0`           | All IPv6 addresses                                        |

## Managing Rules

You can update or delete existing rules at any time. Changes take effect shortly after saving.

> **info**
>
> Access control rules are only available for TCP and UDP services. HTTP services can use other methods like [Basic Auth](/guides/basic-auth) or private networking with [NetBird](/private-networking/netbird) or [Twingate](/private-networking/twingate) to restrict access.