From 21bdc4e8da6780aa80f66a91db152c1176ffe6ff Mon Sep 17 00:00:00 2001 From: Brian E Carpenter Date: Sun, 27 Aug 2023 10:41:30 +1200 Subject: [PATCH] Disallow ULAs in global DNS --- 2. IPv6 Basic Technology/DNS.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/2. IPv6 Basic Technology/DNS.md b/2. IPv6 Basic Technology/DNS.md index ee27864..2b09198 100644 --- a/2. IPv6 Basic Technology/DNS.md +++ b/2. IPv6 Basic Technology/DNS.md @@ -52,6 +52,12 @@ concern: to work in most cases, it is inappropriate if the host in question has a valid IPv6 address, and pointless otherwise. +- Certain IPv6 address types should __never__ be visible in global DNS: ULAs + (starting with `fdxx:` or even `fcxx:`) or link-local (starting with + `fe80::`). Beware that automated mechanisms like Active Directory might + add ULAs to global DNS by default. Of course, it is OK to + include ULAs in _local_ DNS if a split DNS configuration is used. + Some statistics on AAAA records and reachability may be found at [Dan Wing's site](https://www.employees.org/~dwing/aaaa-stats/).