1. DNS/lame_delegation/institute
Contents
DNS Lame Delegations Report 2019-11
http://dnsinstitute.com/research/lame-servers-201911/
The following examples were seen in November 2019. Some of the problems have been resolved, but a few still exist.
1.1. サーバーがない
NSレコードがない場合もある。(clientHold状態など)
- No address for delegated NS target (A / AAAA がない)
- NS target recursively points to itself or parent
- Non-existent server (間違い名など NXDOMAIN)
1.2. 返事がない/不正
- Nameserver refuses to answer
- Nameserver returns a non-authoritative answer
- Nameserver returns a failure SERVFAIL or FORMERR