[dns-operations] Questions on DNS Flag day 2020 proposal

Mark Andrews marka at isc.org
Mon Jun 17 23:28:36 UTC 2019

One thing that hasn’t been mentioned so far with respect to TCP
fallback is populating the additional section with glue and setting
TC=1 when it doesn’t fit.

STD13 doesn’t say glue as optional and not being able to fit glue
into a referral response should result in TC=1 being set.  Named
does this if the first GLUE RRset doesn’t fit.  It should do this
if any of the GLUE RRsets don’t fit.  If we are no longer going to
be pandering to clients that don’t support TCP this is one of the
things I’d like to fix.

Lack of glue in referrals has caused DNS resolution failures in the


Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka at isc.org

More information about the dns-operations mailing list