我在 Amazon Route53 上的 DNS 区域中有错字。我有一个从 53 开始的 IP,而它应该是 52。我现在在 Route53 上更改了它,但我仍然从 dig 和其他使用 UDP 的解析器机制获取旧数据。如果我强制 TCP,我会得到正确的数据。
以下是此时 Route53 上的实际 DNS 记录,以 BIND 语法表示:
$ORIGIN templatolio.com.
@ 3600 IN A 52.32.48.83
这是使用 UDP 的结果。请注意,ANSWER 以 53 开头,Authority 为 0:
C:\>dig templatolio.com @ns1.aleyant.net
; <<>> DiG 9.10.3-P4 <<>> templatolio.com @ns1.aleyant.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34565
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;templatolio.com. IN A
;; ANSWER SECTION:
templatolio.com. 2289 IN A 53.32.48.83
;; Query time: 19 msec
;; SERVER: 205.251.199.16#53(205.251.199.16)
;; WHEN: Thu Sep 29 11:58:33 EDT 2016
;; MSG SIZE rcvd: 60
这是使用 TCP 的结果。请注意,ANSWER 以 52 开头,因为它应该:
C:\>dig +tcp templatolio.com @ns1.aleyant.net
; <<>> DiG 9.10.3-P4 <<>> +tcp templatolio.com @ns1.aleyant.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59721
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 8, ADDITIONAL: 5
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;templatolio.com. IN A
;; ANSWER SECTION:
templatolio.com. 3600 IN A 52.32.48.83
;; AUTHORITY SECTION:
templatolio.com. 3600 IN NS ns-1437.awsdns-51.org.
templatolio.com. 3600 IN NS ns-1808.awsdns-34.co.uk.
templatolio.com. 3600 IN NS ns-670.awsdns-19.net.
templatolio.com. 3600 IN NS ns-88.awsdns-11.com.
templatolio.com. 3600 IN NS ns1.aleyant.net.
templatolio.com. 3600 IN NS ns2.aleyant.net.
templatolio.com. 3600 IN NS ns3.aleyant.net.
templatolio.com. 3600 IN NS ns4.aleyant.net.
;; ADDITIONAL SECTION:
ns1.aleyant.net. 3600 IN A 205.251.199.16
ns2.aleyant.net. 3600 IN A 205.251.194.158
ns3.aleyant.net. 3600 IN A 205.251.197.157
ns4.aleyant.net. 300 IN A 205.251.192.88
;; Query time: 23 msec
;; SERVER: 205.251.199.16#53(205.251.199.16)
;; WHEN: Thu Sep 29 11:59:00 EDT 2016
;; MSG SIZE rcvd: 340
刚刚想到:这可能是我的 ISP 拒绝 UDP DNS 数据包吗?