Problem
想测试 udp 端口连通性,但是 telnet 连接被拒绝,用 telnet 似乎不对。
Solution
appledeMacBook-Pro:~ xxx$ nc -vuz x.x.x.x 514
found 0 associations
found 1 connections:
1: flags=82<CONNECTED,PREFERRED>
outif (null)
src x.x.x.x port 52491
dst x.x.x.x port 514
rank info not available
Connection to x.x.x.x port 514 [udp/syslog] succeeded!
说明该 udp 端口正常监听。