一天莫名奇妙发现ping dig 等基础命令都无法正常使用。还好能浏览器能正常访问，，，，
赶紧拿baidu试试^-^
; <<>> DiG 9.10.6 <<>> baidu.com
;; global options: +cmd
;; connection timed out; no servers could be reached
ping: cannot resolve www.baidu.com: Unknown host
看到这是不是一开始以为dns被污染了，赶紧查下dns配置，一看也都挺正常.
#
# macOS Notice
#
# This file is not consulted for DNS hostname resolution, address
# resolution, or the DNS query routing mechanism used by most
# processes on this system.
#
# To view the DNS configuration used by this system, use:
# scutil --dns
#
# SEE ALSO
# dns-sd(1), scutil(8)
#
# This file is automatically generated.
#
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 114.114.114.114
还刷新了好几次dns,然并卵...有点抓狂了...
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
由于工作日要上班，将就了2天，晚上回到家仍不死心，接着搞
偶然看到一个说可能开了防火墙，一看果然。把firewall关闭，一下子都恢复正常了 哈哈哈，，心情大爽。不知道什么时候手残设置了这个，折腾了2天 。
记之于此 20240924 23:43。