dig +trace math.stackexchange.com
; <<>> DiG 9.9.5-9+deb8u6-Debian <<>> +trace math.stackexchange.com
;; global options: +cmd
. 229248 IN NS c.root-servers.net.
. 229248 IN NS l.root-servers.net.
. 229248 IN NS i.root-servers.net.
. 229248 IN NS h.root-servers.net.
. 229248 IN NS j.root-servers.net.
. 229248 IN NS d.root-servers.net.
. 229248 IN NS f.root-servers.net.
. 229248 IN NS e.root-servers.net.
. 229248 IN NS k.root-servers.net.
. 229248 IN NS g.root-servers.net.
. 229248 IN NS m.root-servers.net.
. 229248 IN NS b.root-servers.net.
. 229248 IN NS a.root-servers.net.
;; Received 239 bytes from 208.67.222.222#53(208.67.222.222) in 495 ms
Received 239 bytes，
下面这个内容怎么数也超过239bytes,
. 229248 IN NS c.root-servers.net.
. 229248 IN NS l.root-servers.net.
. 229248 IN NS i.root-servers.net.
. 229248 IN NS h.root-servers.net.
. 229248 IN NS j.root-servers.net.
. 229248 IN NS d.root-servers.net.
. 229248 IN NS f.root-servers.net.
. 229248 IN NS e.root-servers.net.
. 229248 IN NS k.root-servers.net.
. 229248 IN NS g.root-servers.net.
. 229248 IN NS m.root-servers.net.
. 229248 IN NS b.root-servers.net.
. 229248 IN NS a.root-servers.net.
请问，239个字节是怎样计算出来的？
ASCII码:一个英文字母(不分大小写)占一个字节的空间
229248 IN NS a.root-servers.net.
不算里面的空格，这就29个字节了
29*13=377
显示的传输的未必一样。