1. watchA
Ubuntu側はmtu 1280に設定されているのだが、
- サーバー側はudp: 1452で送ってくるのだろうか。
- 当然フラグメント化されるはず。
2. whois
$ dig -t txt long.qmail.jp @1.1.1.1 ; <<>> DiG 9.12.3 <<>> -t txt long.qmail.jp @1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49129 ;; flags: qr rd ra; QUERY: 1, ANSWER: 20, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1452 ;; QUESTION SECTION: ;long.qmail.jp. IN TXT ;; ANSWER SECTION: long.qmail.jp. 86400 IN TXT "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd" long.qmail.jp. 86400 IN TXT "eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee" long.qmail.jp. 86400 IN TXT "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" long.qmail.jp. 86400 IN TXT "gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg" long.qmail.jp. 86400 IN TXT "hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh" long.qmail.jp. 86400 IN TXT "iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii" long.qmail.jp. 86400 IN TXT "jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj" long.qmail.jp. 86400 IN TXT "00000000000000000000000000000000000000000000000000000000000000" long.qmail.jp. 86400 IN TXT "11111111111111111111111111111111111111111111111111111111111111" long.qmail.jp. 86400 IN TXT "22222222222222222222222222222222222222222222222222222222222222" long.qmail.jp. 86400 IN TXT "33333333333333333333333333333333333333333333333333333333333333" long.qmail.jp. 86400 IN TXT "44444444444444444444444444444444444444444444444444444444444444" long.qmail.jp. 86400 IN TXT "55555555555555555555555555555555555555555555555555555555555555" long.qmail.jp. 86400 IN TXT "66666666666666666666666666666666666666666666666666666666666666" long.qmail.jp. 86400 IN TXT "77777777777777777777777777777777777777777777777777777777777777" long.qmail.jp. 86400 IN TXT "88888888888888888888888888888888888888888888888888888888888888" long.qmail.jp. 86400 IN TXT "99999999999999999999999999999999999999999999999999999999999999" long.qmail.jp. 86400 IN TXT "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" long.qmail.jp. 86400 IN TXT "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb" long.qmail.jp. 86400 IN TXT "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc" ;; Query time: 2024 msec ;; SERVER: 1.1.1.1#53(1.1.1.1) ;; WHEN: 日 12月 23 17:52:21 JST 2018 ;; MSG SIZE rcvd: 1542 tmaeno@u16:~$
8.8.8.8からの返答はこうだが、TCPは使われていない。(ということはフラグメント?)
; EDNS: version: 0, flags:; udp: 512