Features#

Basic Usage#

dnspropagation [OPTIONS] TYPE DOMAIN

TYPE is any DNS record type (A, AAAA, TXT, MX, CNAME, CAA, …). It is case-insensitive. DOMAIN is stripped of any protocol, port, or path — https://example.com:443/path is treated as example.com.

Output Formats#

Table (default)#

Prints a colour-coded PrettyTable to stdout. Answers matching --expected are green, mismatches are red, empty answers are yellow, and timeouts are red.

--json#

Outputs a JSON array. Each element represents one server:

[
  {
    "server": {
      "ipv4": "8.8.8.8",
      "owner": "google",
      "tags": ["global", "unfiltered"]
    },
    "answer": ["142.250.185.46"]
  }
]

--yaml#

Same structure as JSON, printed as YAML.

--html#

Writes a self-contained HTML page (embedded CSS, no external dependencies) to stdout. Pipe it to a file:

dnspropagation --html A example.com > report.html

--no-color#

Disables ANSI escape codes in table output. Useful when piping to a file or a CI log viewer that does not interpret colour codes.

--ttl#

Adds a TTL column (or field) to the output showing the time-to-live value returned by each server.

Server Selection#

--server IP#

Add a specific resolver by IPv4 address. Can be repeated. When at least one --server flag is given, the default server list is not used.

dnspropagation --server 8.8.8.8 --server 1.1.1.1 A example.com

--custom_list PATH_OR_URL#

Load servers from a YAML file on disk or over HTTP/HTTPS. Remote files are fetched with a 10-second timeout and must be under 1 MB.

Required YAML schema:

- ipv4: "1.1.1.1"        # required — must be a valid IPv4 address
  owner: "cloudflare"    # optional
  tags:                  # optional
    - global
    - unfiltered

dnspropagation --custom_list ./my-servers.yaml A example.com
dnspropagation --custom_list https://example.com/resolvers.yaml A example.com

--random N#

Randomly sample N servers from the active list before querying. Useful for ad-hoc spot-checks against a large custom list.

dnspropagation --random 3 A example.com

Filtering#

--tags TAG[,TAG...]#

Keep only servers that have all specified tags (AND logic). Can be repeated; comma-separated values are flattened.

# Only global unfiltered resolvers
dnspropagation --tags global,unfiltered A example.com

# Same result, two flags
dnspropagation --tags global --tags unfiltered A example.com

--owner NAME#

Keep only servers whose owner matches NAME. Can be repeated; matching is OR logic across values.

# Only Google and Cloudflare
dnspropagation --owner google --owner cloudflare A example.com

Tags and owner filters can be combined — only servers satisfying both conditions are queried.

Query Options#

--timeout SECONDS#

Per-query timeout as a float. If a server does not respond within this time its answer is recorded as ["timed out"].

dnspropagation --timeout 1.5 A example.com

--expected VALUE#

Assert that every server returns VALUE. Can be repeated to allow multiple valid answers. Servers whose answer does not match any expected value cause the tool to exit with code 5. Timeouts are excluded from this check.

dnspropagation --server 8.8.8.8 --expected 93.184.216.34 A example.com

Batch Mode#

--file PATH#

Run multiple record/domain queries defined in a YAML file. Output is always JSON.

- type: A
  domain: example.com
- type: TXT
  domain: example.com
- type: MX
  domain: example.com

dnspropagation --file checks.yaml

Utility#

--show-default#

Print the built-in server list to stdout. Add --yaml to get YAML output.

dnspropagation --show-default
dnspropagation --show-default --yaml

--version#

Print the installed version and exit.