TIL: Restricting DiG to UDP only with +ignore

[Fred Morris]

If the UDP query returns TC=1 DiG retries with TCP. I want to see the
UDP results and am unable to. Specifying +notcp makes no difference. The
correct option is +ignore:

    # dig @127.0.0.1 'web_client\;*\;athena\;*.keys.redis.sophia.m3047' txt +notcp | tail
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;194.55.186.216,404;athena;1670154435"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;43.134.92.151,400;athena;1670132664"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;35.162.155.28,200;athena;1670132664"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;159.89.118.246,200;athena;1670132664"

    ;; Query time: 9 msec
    ;; SERVER: 127.0.0.1#53(127.0.0.1) (TCP)
    ;; WHEN: Sun Dec 04 18:42:19 PST 2022
    ;; MSG SIZE  rcvd: 7500

    # dig @127.0.0.1 'web_client\;*\;athena\;*.keys.redis.sophia.m3047' txt +ignore | tail
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;80.94.92.40,200;athena;1670111034"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;161.35.213.88,200;athena;1670154435"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;103.10.62.92,404;athena;1670176114"
    web_client\;*\;athena\;*.keys.redis.sophia.m3047. 30 IN TXT "web_client;54.185.160.223,200;athena;1670154435"

    ;; Query time: 16 msec
    ;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
    ;; WHEN: Sun Dec 04 18:42:26 PST 2022
    ;; MSG SIZE  rcvd: 1193

The "tell" is that on the footer SERVER line it reports the protocol.
Note that in the first case it's TCP, even though +notcp was specified.
(The MSG SIZE is also a clue.)

Searching the intertubes wasn't much help. When I tried to search the
list archives I got a Gateway Timeout. :-( Anyway, it's been a minor
personal annoyance for a while; hopefully this helps somebody else with
a problem they didn't know they had.

--

Fred Morris, internet plumber


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/bind-users/attachments/20221204/66362a8a/attachment.htm>