NAME¶

dog — a command-line DNS client

SYNOPSIS¶

dog [options] [domains...]

dog is a command-line DNS client. It has colourful output, supports the DNS-over-TLS and DNS-over-HTTPS protocols, and can emit JSON.

EXAMPLES¶

dog example.net

Query the A record of a domain using default settings

dog example.net MX

...looking up MX records instead

dog example.net MX @1.1.1.1

...using a specific nameserver instead

dog example.net MX @1.1.1.1 -T

...using TCP rather than UDP

dog -q example.net -t MX -n 1.1.1.1 -T

As above, but using explicit arguments

QUERY OPTIONS¶

-q, --query=HOST

Host name or domain name to query.

-t, --type=TYPE

Type of the DNS record being queried (A, MX, NS...)

-n, --nameserver=ADDR

Address of the nameserver to send packets to.

--class=CLASS

Network class of the DNS record being queried (IN, CH, HS)

By default, dog will request A records using the system default resolver. At least one domain name must be passed — dog will not automatically query the root nameservers.

Query options passed in using a command-line option, such as `--query lookup.dog' or `--type MX', or as plain arguments, such as `lookup.dog' or `MX'. dog will make an intelligent guess as to what plain arguments mean (MX is quite clearly a type), which makes it easier to compose ad-hoc queries quickly. If precision is desired, use the long-form options.

If more than one domain, type, nameserver, or class is specified, dog will perform one query for each combination, and display the combined results in a table. For example, passing three type arguments and two domain name arguments will send six requests.

DNS traditionally uses port 53 for both TCP and UDP. To use a resolver with a different port, include the port number after a colon (:) in the nameserver address.

SENDING OPTIONS¶

--edns=SETTING

Whether to opt in to DNS. This can be `disable', `hide', or `show'.

--txid=NUMBER

Set the transaction ID to a specific value.

-Z=TWEAKS

Set uncommon protocol-level tweaks.

TRANSPORT OPTIONS¶

-U, --udp

Use the DNS protocol over UDP.

-T, --tcp

Use the DNS protocol over TCP.

-S, --tls

Use the DNS-over-TLS protocol.

-H, --https

Use the DNS-over-HTTPS protocol.

By default, dog will use the UDP protocol, automatically re-sending the request using TCP if the response indicates that the message is too large for UDP. Passing --udp will only use UDP and will fail in this case; passing --tcp will use TCP by default.

The DNS-over-TLS (DoT) and DNS-over-HTTPS (DoH) protocols are available with the --tls and --https options. Bear in mind that the system default resolver is unlikely to respond to requests using these protocols.

Note that if a hostname or domain name is given as a nameserver, rather than an IP address, the resolution of that host is performed by the operating system, not by dog.

Unlike the others, the HTTPS transport type requires an entire URL, complete with protocol, domain name, and path.

OUTPUT OPTIONS¶

-1, --short

Short mode: display nothing but the first result.

-J, --json

Display the output as JSON.

--color, --colour=WHEN

When to colourise the output. This can be `always', `automatic', or `never'.

--seconds

Do not format durations as hours and minutes; instead, display them as seconds.

--time

Print how long the response took to arrive.

META OPTIONS¶

--help

Displays an overview of the command-line options.

--version

Displays the version of dog being invoked.

ENVIRONMENT VARIABLES¶

dog responds to the following environment variables:

RECORD TYPES¶

dog understands and can interpret the following record types:

A

IPv4 addresses

AAAA

IPv6 addresses

CAA

permitted certificate authorities

CNAME

canonical domain aliases

HINFO

system information and, sometimes, forbidden request explanations

LOC

location information

MX

e-mail server addresses

NAPTR

DDDS rules

NS

domain name servers

OPT

extensions to the DNS protocol

PTR

pointers to canonical names, usually for reverse lookups

SOA

administrative information about zones

SRV

IP addresses with port numbers

SSHFP

SSH key fingerprints

TLSA

TLS certificates, public keys, and hashes

TXT

arbitrary textual information

When a response DNS packet contains a record of one of these known types, dog will display it in a table containing the type name and a human-readable summary of its contents.

Records with a type number that does not map to any known record type will still be displayed. As they cannot be interpreted, their contents will be displayed as a series of numbers instead.

dog also contains a list of record type names that it knows the type number of, but is not able to interpret, such as IXFR or ANY or AFSDB. These are acceptable as command-line arguments, meaning you can send an AFSDB request with `dog AFSDB'. However, their response contents will still be displayed as numbers. They may be supported in future versions of dog.

PROTOCOL TWEAKS¶

The -Z command-line argument can be used one or more times to set some protocol-level options in the DNS queries that get sent. It accepts the following values:

aa

Sets the AA (Authoritative Answers) bit in the query.

ad

Sets the AD (Authentic Data) bit in the query.

bufsize=NUM

Sets the UDP payload size field in the OPT field in the query. This has no effect if EDNS is diabled.

cd

Sets the CD (Checking Disabled) bit in the query.

EXIT STATUSES¶

0

If everything goes OK.

1

If there was a network, I/O, or TLS error during operation.

2

If there is no result from the server when running in short mode. This can be any received server error, not just NXDOMAIN.

3

If there was a problem with the command-line arguments.

AUTHOR¶

dog is maintained by Benjamin `ogham' Sago.

Website: https://dns.lookup.dog/

Source code: https://github.com/ogham/dog