dog/man/dog.1.md

% dog(1) v0.1.0

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:

DOG_DEBUG

Set this to any non-empty value to have dog emit debugging information to standard error. For more in-depth output, set this to the exact string ‘trace’.

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.

4 : If there was a problem obtaining the system nameserver information.

AUTHOR

dog is maintained by Benjamin ‘ogham’ Sago.

Website: https://dns.lookup.dog/ \ Source code: https://github.com/ogham/dog