# Cis Ubuntu1604 V200 2 1 8

> Ensure DNS Server is not installed

- Skill: `cyberstrikeus/cis-ubuntu1604-v200-2-1-8` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1604-v200-2-1-8`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1604-v200-2-1-8/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu1604-v200-2-1-8

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# 2.1.8 Ensure DNS Server is not installed (Automated)

## Description

The Domain Name System (DNS) is a hierarchical naming system that maps names to IP addresses for computers, services and other resources connected to a network.

## Rationale

Unless a system is specifically designated to act as a DNS server, it is recommended that the package be deleted to reduce the potential attack surface.

## Audit Procedure

### Command Line

Run the following command to verify DNS server is not installed:

```bash
dpkg -s bind9 | grep -E '(Status:|not installed)'
```

## Expected Result

```
dpkg-query: package 'bind9' is not installed and no information is available
```

## Remediation

### Command Line

Run the following commands to disable DNS server:

```bash
apt purge bind9
```

## Default Value

bind9 is not installed on minimal server installations.

## References

1. CIS Controls v7 - 9.2 Ensure Only Approved Ports, Protocols and Services Are Running

## Profile

- Level 1 - Server
- Level 1 - Workstation