当未安装 Telnet 时,人们使用什么来检查端口是否打开且可访问?例如,我曾经使用过这种技术telnet <destination>
,即使 telnet 无法与另一端的系统交互,我也知道它在那里。
由于 Windows 2008 未安装 telnet,所以我有点迷茫。那么我可以用什么来代替呢?如果 Linux 或 Solaris 中也没有,请提供一些方法。
我是一名在不同站点工作的顾问。由于多种原因(访问权限、更改控制时间、如果我安装它,明年有人使用它,我们有一些责任等),我无法在其他人的服务器上安装。但是 USB 或其他自带的、非安装的工具会很棒...
答案1
像老板一样使用 Powershell
基本代码
$ipaddress = "4.2.2.1"
$port = 53
$connection = New-Object System.Net.Sockets.TcpClient($ipaddress, $port)
if ($connection.Connected) {
Write-Host "Success"
}
else {
Write-Host "Failed"
}
一句话
PS C:\> test-netconnection -ComputerName 4.2.2.1 -Port 53
将其转换为 cmdlet
[CmdletBinding()]
Param(
[Parameter(Mandatory=$True,Position=1)]
[string]$ip,
[Parameter(Mandatory=$True,Position=2)]
[int]$port
)
$connection = New-Object System.Net.Sockets.TcpClient($ip, $port)
if ($connection.Connected) {
Return "Connection Success"
}
else {
Return "Connection Failed"
}
保存为脚本并随时使用
然后,在 powershell 或 cmd 提示符中使用以下命令:
PS C:\> telnet.ps1 -ip 8.8.8.8 -port 53
或者
PS C:\> telnet.ps1 8.8.8.8 53
答案2
以下是几种不使用 telnet 来测试 TCP 端口的不同方法。
重击(手册页)
# cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C
# cat < /dev/tcp/127.0.0.1/23
bash: connect: Connection refused
bash: /dev/tcp/127.0.0.1/23: Connection refused
卷曲
# curl -v telnet://127.0.0.1:22
* About to connect() to 127.0.0.1 port 22 (#0)
* Trying 127.0.0.1... connected
* Connected to 127.0.0.1 (127.0.0.1) port 22 (#0)
SSH-2.0-OpenSSH_5.3
^C
# curl -v telnet://127.0.0.1:23
* About to connect() to 127.0.0.1 port 23 (#0)
* Trying 127.0.0.1... Connection refused
* couldn't connect to host
* Closing connection #0
curl: (7) couldn't connect to host
Python
# python
Python 2.6.6 (r266:84292, Oct 12 2012, 14:23:48)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import socket
>>> clientsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> clientsocket.connect(('127.0.0.1', 22))
>>> clientsocket.send('\n')
1
>>> clientsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> clientsocket.connect(('127.0.0.1', 23))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in connect
socket.error: [Errno 111] Connection refused
Perl
# perl
use IO::Socket::INET;
$| = 1;
my $socket = new IO::Socket::INET(
PeerHost => '127.0.0.1',
PeerPort => '22',
Proto => 'tcp',
);
die "cannot connect to the server $!\n" unless $socket;
print "connected to the server\n";
^D
connected to the server