Linux下检测端口是否可达
【一句话】示例为查看某个IP下的80端口是否开启,结果显示是该IP下的80端口可达
# nmap -p 80 10.56.249.212
Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2011-07-27 12:51 EDT
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using –system-dns or specify valid servers with –dns_servers[……]