今天首次接触项目的服务器，命令行敲radiusd -X启动，提示错误如下：
ERROR:Failed to open socket: cannot bind socket: Address already in use
/usr/local/etc/raddb/radiusd.conf[236]: Error binding to port for 0.0.0.0 port 1812
radius是原本就装好的，于是检查1812端口：
lsof -i:1812
发现是radiusd占用了该端口。果断kill掉，重新运行radiusd -X，启动成功。提示：
Listening on authentication address * port 1812
Listening on accounting address * port 1813
Listening on proxy address * port 1814
Ready to process requests.
结束。