---
title: "What do +EDC and other letters I see in my query log mean?"
slug: "aa-00434"
description: "+EDC in a query log means that it is recursive, the sender is using EDNS0, the sender understands DNSSEC, and validation checking is disabled."
tags: ["logs"]
updated: 2018-10-05T17:56:02Z
published: 2018-10-05T17:56:03Z
canonical: "kb.isc.org/aa-00434"
---

> ## 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.

# What do +EDC and other letters I see in my query log mean?

This is documented in the BIND Administrator Reference Manual (which you'll find both [here in our Knowledgebase](https://kb.isc.org/docs/aa-01031) and in the BIND source code tarball).

Look for the section that deals with logging categories, and specifically at category **queries**:

```
The query log entry first reports a client object identifier in @0x<hexadecimal-number> format. Next, it reports the client's IP address and port number, and the query name, class and type. Next, it reports whether the Recursion Desired flag was set (+ if set, - if not set), if the query was signed (S), EDNS was in used along with the EDNS version number (E(#)), if TCP was used (T), if DO(DNSSEC Ok) was set (D), if CD (Checking Disabled) was set (C), if a valid DNS Server COOKIE was received (V), or if a DNS COOKIE option without a valid Server COOKIE was present (K). After this the destination address the query was sent to is reported.

Note: This reflects BIND 9.11.0 behaviour.
```

+EDC on a query indicates that it is:

- Recursive (+) - it has come from a client or a server that is forwarding queries to your server.
- The sender is using EDNS0 (using larger UDP packet sizes and signalling the size that can be accepted).
- The sender understands DNSSEC (D) - this is a request to your server to include any DNSSEC material associated with answer in the query reply.
- DNSSEC validation checking is disabled (C) - the sender wants the answer anyway, even if the validation checks fail.