---
title: Security Groups
---

# Security Groups Tab

Security groups act as virtual firewalls that control inbound and outbound traffic for the cluster. The **Security Groups** tab lists every security group currently attached to the cluster, along with its rules, and lets you attach and detach groups.

To open it, select a cluster and choose the **Security Groups** tab.

:::warning
The control plane requires **TCP port 6443** to be allowed, or `kubectl` and cluster clients cannot reach the API server. The cluster networking overlay also requires **UDP port 8472**. Make sure at least one attached security group permits these ports.
:::

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## Attach a Security Group

1. On the **Security Groups** tab, select **Attach Security Group**.
2. Select one or more security groups from the available list.
3. Select **Attach** to confirm.

## Detach a Security Group

1. Locate the security group you want to remove.
2. Select **Detach** next to it.
3. Confirm in the dialog.

:::note
At least **one** security group must remain attached to the cluster at all times - the portal prevents removing the last one.
:::

## Allow All Traffic

If traffic is being blocked by a conflict between OS firewall services and security group rules, use **Allow All Traffic** to temporarily permit all inbound and outbound traffic. This creates and attaches an allow-all security group so you can isolate the conflict, then tighten the rules again once it is resolved.

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## Related Resources

| Resource                                                                              | Use it for                         |
| ------------------------------------------------------------------------------------- | ---------------------------------- |
| [Connect to a Cluster](/docs/myaccount/kubernetes/getting-started/connect-to-cluster) | Why port 6443 must be open.        |
| [Networking](/docs/myaccount/kubernetes/manage/networking)                            | Service IPs and external exposure. |
| [Node Security](/docs/myaccount/node/manage/security)                                 | Security group concepts and rules. |