---
title: "How can I disable IPv6 recursive queries on my resolver?"
slug: "aa-00206"
description: "How do I stop my resolver from using IPv6 when doing recursion?"
tags: ["IPv6", "resolver", "recursion"]
updated: 2023-02-01T14:03:51Z
published: 2023-02-01T14:03:51Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.isc.org/llms.txt
> Use this file to discover all available pages before exploring further.

# How can I disable IPv6 recursive queries on my resolver?

On some networks, IPv6 is used internally, but is not supported by the link to the rest of the Internet. This degrades resolver performance due to `named` attempting to use IPv6 transport to send queries that can never be answered.

BIND resolvers query other authoritative DNS servers in order to provide query responses to client queries. During recursive resolution, they will 'learn' the names and addresses of other servers, both IPv4 and IPv6. To prevent your server from using the learned IPv6 addresses itself during recursion, you can add a `server` clause to named.conf:

```
server ::/0 { bogus yes; };
```

To prevent queries from being sent to IPv6 addresses outside the network, while still allowing them inside (i.e. locally), use a pair of `server` clauses:

```
server fd81:ec6c:bd62::/48 { bogus no; }; // site ULA prefix 
server ::/0 { bogus yes; };
```

This allows queries to be sent to addresses in the fd81:ec6c:bd62::/48 network prefix, but not to any other IPv6 addresses.

Use of IPv6 transport can also be disabled entirely by using the `named -4` command line option, but you should not do this if you still want your resolver to learn and make available to clients, the IPv6 addresses of Internet authoritative DNS servers.

          NOTE: We currently recommend using `named -4` instead of `server ::/0 { bogus yes; };`

          

Due to the way named resolver code internally handles the lists of servers authoritative for a domain, using `server ::/0 { bogus yes; };` to disable IPv6 transport being used for recursive queries can unfortunately sometimes cause intermittent SERVFAIL responses instead to clients. See [https://gitlab.isc.org/isc-projects/bind9/-/issues/1964](https://gitlab.isc.org/isc-projects/bind9/-/issues/1964) for more details.