On 9 Nov 2020, at 12:01, Rob McEwen <rob@invaluement.com> wrote:
On 11/8/2020 7:10 PM, Matt Palmer wrote:
On Fri, Nov 06, 2020 at 05:07:26AM -0500, Dovid Bender wrote:
Sorry if this is a bit OT. Recently several different vendors (in completely different fields) where they white label for us asked us to remove A records that we have going to them and replace them with CNAME records. Is there anything *going around* in the security aranea that has caused this? The closest thing to a *security* issue I can think of is IP agility in the face of DDoS attacks -- most booter-style attacks are dumb as rocks, and null-routing the target IP and moving all the customers on that IP to another one is the easiest solution.
However, there are many *other* great reasons to get customers to CNAME onto their SaaS vendors, including:
* No need to coordinate routine renumbering events; * IPv6 support; * CAA record (SSL cert issuance) support; and * no doubt a bunch of other reasons I've forgotten for the moment.
Basically, if you sign up for a SaaS that uses your own domain and they *don't* give you a CNAME target to point at, I'd be very cautious, because they're either *very* new to the game, or they're probably also operationally deficient in a lot of other areas, too.
- Matt
except - don't forget that the root of a domain (that domain without "www.” or any other label) - cannot have a CNAME as the "A" record - fwiw…
Which is why there are HTTPS and SVCB records coming and SRV exists. You don’t need CNAME, you need indirection. Indirection does require a small amount of client support.
-- Rob McEwen, invaluement
-- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org