1. watchA
DNS-OARCのサービス https://www.dns-oarc.net/oarc/services/replysizetest
$ dig +short rs.dns-oarc.net TXT @127.0.0.1 rst.x4090.rs.dns-oarc.net. rst.x4058.x4090.rs.dns-oarc.net. rst.x4064.x4058.x4090.rs.dns-oarc.net. "39.110.135.12 DNS reply size limit is at least 4090" "Tested at 2018-11-08 03:55:30 UTC" "39.110.135.12 sent EDNS buffer size 4096"
$ dig rs.dns-oarc.net TXT @127.0.0.1
; <<>> DiG 9.12.1 <<>> rs.dns-oarc.net TXT @127.0.0.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2708 ;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;rs.dns-oarc.net. IN TXT ;; ANSWER SECTION: rs.dns-oarc.net. 60 IN CNAME rst.x487.rs.dns-oarc.net. rst.x487.rs.dns-oarc.net. 59 IN CNAME rst.x461.x487.rs.dns-oarc.net. rst.x461.x487.rs.dns-oarc.net. 58 IN CNAME rst.x466.x461.x487.rs.dns-oarc.net. rst.x466.x461.x487.rs.dns-oarc.net. 57 IN TXT "39.110.135.12 sent EDNS buffer size 512" rst.x466.x461.x487.rs.dns-oarc.net. 57 IN TXT "39.110.135.12 DNS reply size limit is at least 487" rst.x466.x461.x487.rs.dns-oarc.net. 57 IN TXT "Tested at 2018-11-08 03:53:40 UTC" ;; Query time: 4728 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Nov 08 12:53:40 JST 2018 ;; MSG SIZE rcvd: 274
$ dig rs.dns-oarc.net TXT @127.0.0.3
; <<>> DiG 9.12.1 <<>> rs.dns-oarc.net TXT @127.0.0.3 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 32551 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1220 ;; QUESTION SECTION: ;rs.dns-oarc.net. IN TXT ;; Query time: 564 msec ;; SERVER: 127.0.0.3#53(127.0.0.3) ;; WHEN: Thu Nov 08 12:56:44 JST 2018 ;; MSG SIZE rcvd: 44
2. ???
https://twitter.com/tss_ontap_o/status/1060335417101180928
MTU or EDNS size ?
DNSLAB.JP: 1220 FR: 1432 NL: 4096 JP: 4096 COM: 4096 IIJ ; 4096 OCN ; 4096 SO-NET ; 4096 JPNIC : 4096 ONAMAE: 4096 9:57 - 2018年11月8日