telnet
telnet是windows标准服务，可以直接用；如果是linux机器，需要安装telnet.
用法: telnet ip port
1）先用telnet连接不存在的端口
1
2
3
|
[root@localhost ~]# telnet 10.0.250.3 80
Trying 10.0.250.3...
telnet: connect to address 10.0.250.3: Connection refused #直接提示连接被拒绝
|
2）再连接存在的端口
1
2
3
4
5
6
7
8
|
[root@localhost ~]# telnet localhost 22
Trying ::1...
Connected to localhost. #看到Connected就连接成功了
Escape character is '^]'.
SSH-2.0-OpenSSH_5.3
a
Protocol mismatch.
Connection closed by foreign host.
|
ssh
ssh是linux的标准配置并且最常用，可以用来判断端口吗？
用法: ssh -v -p port username@ip
-v 调试模式(会打印日志).
-p 指定端口
username可以随意
1）连接不存在端口
1
2
3
4
5
6
7
8
9
|
[root@localhost ~]# ssh 10.0.250.3 -p 80
ssh: connect to host 10.0.250.3 port 80: Connection refused
[root@localhost ~]# ssh 10.0.250.3 -p 80 -v
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 10.0.250.3 [10.0.250.3] port 80.
debug1: connect to address 10.0.250.3 port 80: Connection refused
ssh: connect to host 10.0.250.3 port 80: Connection refused
|
2）连接存在的端口
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
[root@localhost ~]# ssh ... -p
a
^]
^C
[root@localhost ~]# ssh ... -p -v
OpenSSH_.p, OpenSSL ..e-fips Feb
debug: Reading configuration data /etc/ssh/ssh_config
debug: Applying options for *
debug: Connecting to ... [...] port .
debug: Connection established.
debug: permanently_set_uid: /
debug: identity file /root/.ssh/identity type -
debug: identity file /root/.ssh/identity-cert type -
debug: identity file /root/.ssh/id_rsa type -
debug: identity file /root/.ssh/id_rsa-cert type -
debug: identity file /root/.ssh/id_dsa type -
debug: identity file /root/.ssh/id_dsa-cert type -
a
^C
|
不用-v选项也可以咯
wget
wget是linux下的下载工具，需要先安装.
用法: wget ip:port
1）连接不存在的端口
1
2
3
|
[root@localhost ~]# wget ...:
---- ::-- http://.../
Connecting to ...:... failed: Connection refused.
|
2）连接存在的端口
1
2
3
4
|
[root@localhost ~]# wget ...:
---- ::-- http://...:/
Connecting to ...:... connected.
HTTP request sent, awaiting response...
|
curl
命令格式：
curl [参数] [URL地址]
命令功能：
在Linux中curl是一个利用URL规则在命令行下工作的文件传输工具，可以说是一款很强大的http命令行工具。但按传统，习惯称url为下载工具
(1) 不存在端口
获取不到结果
(2) 存在端口
1
2
3
4
5
6
7
8
|
curl 1.1.1.1:8000
<!DOCTYPE html>
<html>
<head>xxx</head>
<body>
......
</body>
</html>
|
nc
一、nc命令检测端口的用法
nc -v -w 10 %IP% -z %PORT%
-v 显示指令执行过程。
-w <超时秒数> 设置等待连线的时间。
-u 表示使用UDP协议
-z 使用0输入/输出模式，只在扫描通信端口时使用。
例1：扫描指定的8080端口
1
2
|
nc -v -w 10 -z 192.168.0.100 8080
Connection to 192.168.0.100 8080 port [tcp/http] succeeded!
|
例2：扫描20到25的端口范围，并详细输出。
1
2
3
4
5
6
7
|
# nc -v -w 2 -z 192.168.0.100 20-25
nc: connect to 192.168.0.100 port 20 (tcp) failed: Connection refused
nc: connect to 192.168.0.100 port 21 (tcp) failed: Connection refused
Connection to 192.168.0.100 22 port [tcp/ssh] succeeded!
nc: connect to 192.168.0.100 port 23 (tcp) failed: Connection refused
nc: connect to 192.168.0.100 port 24 (tcp) failed: Connection refused
nc: connect to 192.168.0.100 port 25 (tcp) failed: Connection refused
|
例3：扫描1到65535的端口范围，只输出打开的端口（去掉-v参数即可）
1
2
3
4
5
6
7
|
# nc -w 1 -z 192.168.0.100 1-65535
Connection to 192.168.0.100 22 port [tcp/ssh] succeeded!
Connection to 192.168.0.100 80 port [tcp/http] succeeded!
Connection to 192.168.0.100 2121 port [tcp/scientia-ssdb] succeeded!
Connection to 192.168.0.100 4004 port [tcp/pxc-roid] succeeded!
Connection to 192.168.0.100 8081 port [tcp/tproxy] succeeded!
Connection to 192.168.0.100 11211 port [tcp/*] succeeded!
|