linux下查看另一台主机的某个端口是否启动命令

以LINUX REDHAT6.3为例：

本机插入 REDHAT6.3系统ISO镜像CD1

1.配置yum本地安装源：

以root用户登录系统

mkdir /mnt/cdrom

mount -t iso9660 /dev/sr0 /mnt/cdrom

cd /etc/yum.repos.d

查看目录是否有.repo后缀文件，没有则创建一个.repo文件,文件名随意。

vi local.repo 

[LOCAL]
name=local
baseurl=file:///mnt/cdrom
enable=1
gpgcheck=0

yum clean all

2.安装nmap,并测试172.24.40.5是否开放80端口

[root@openlab named]# yum install nmap
Loaded plugins: rhnplugin
Repository 'LOCAL' is missing name in configuration, using id
This system is not registered with RHN.
RHN support will be disabled.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package nmap.i686 2:5.21-3.el6 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package         Arch            Version                 Repository        Size
================================================================================
Installing:
 nmap            i686            2:5.21-3.el6            LOCAL            2.2 M

Transaction Summary
================================================================================
Install       1 Package(s)
Upgrade       0 Package(s)

Total download size: 2.2 M
Installed size: 7.2 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : 2:nmap-5.21-3.el6.i686                                   1/1

Installed:
  nmap.i686 2:5.21-3.el6

Complete!

[root@openlab named]# nmap -p 80 172.24.40.5

Starting Nmap 5.21 ( http://nmap.org ) at 2013-01-09 17:00 CST
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers
Nmap scan report for 172.24.40.5
Host is up (0.00034s latency).
PORT   STATE SERVICE
80/tcp open  http
MAC Address: 00:0C:29:4E:7D:FE (VMware)

Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds

nmap -p 1-200 目标主机 IP

#1-200为端口范围