#sshserver

[linuxtechlab]

Learn how to install / enable SSH server on Ubuntu 21.04 or older versions.

In most of the Linux distributions, SSH comes installed & we can access those servers using ssh command but with Ubuntu Desktop (& based distros) that is not the case. We are required to install SSH on Ubuntu to be able to access it.

Though we have an ssh client available on Ubuntu, it’s the ssh server that we need to install on Ubuntu. It means we can access other servers from Ubuntu using ssh but other machines will not be able to access our Ubuntu systems.

[osintelligence]

https://bit.ly/3FGxiyR - ShellBot Malware Being Distributed to Linux SSH Servers AhnLab Security Emergency Response Center (ASEC) recently discovered that ShellBot malware is being installed on poorly managed Linux SSH servers. ShellBot, also known as PerlBot, is a DDoS Bot malware developed in Perl that uses IRC protocol to communicate with its C&C server. This old malware has been in steady use and is still being used today to launch attacks against Linux systems. Threat actors attacking server environments use different methods than those used for desktop environments. Poorly managed services or those weak to vulnerability exploitations because they have not been patched to the latest version are prime targets A main example of a poorly managed service is one where simple account credentials are used, causing the server to be vulnerable to dictionary attacks. The ShellBot malware strains covered in this post are believed to have been installed after threat actors used account credentials obtained through scanners and SSH BruteForce malware on target systems. After scanning systems with operational port 22s, threat actors search for systems where the SSH service is active and use a list of commonly used SSH account credentials to initiate their dictionary attack.

[passhotdumps]

Three minutes to take you to understand the terminal access technology

Today I will tell you about terminal access technology. Terminal access refers to the connection of terminal devices and routers, and the completion of data communication between terminal devices and other terminal devices through routers.

There are two types of terminal access implemented by routers: the terminal access initiator and the terminal access receiver.

The terminal access initiator is the party that initiates the TCP connection request. As the client of the TCP connection, it is generally a router;

The terminal access receiver is the party that responds to the TCP connection request. As a TCP connection server, it can be a front-end machine or a router.

Whether the router is the initiator or the receiver, as long as the TCP connection is established, the data stream on the terminal device can be transparently transmitted to the opposite end of the TCP connection.

There are generally five types of terminal access:

TTY terminal access: The initiator is a router and the receiver is a front-end machine. The service terminal is connected to the router through an asynchronous serial port. The router is connected to the front-end computer through the network. The application services run on the front-end computer. The front-end computer interacts with the router through the ttyd program and pushes the business screen to the service terminal through the router. The router is responsible for the transparent transmission of data between its connected service terminals and front-end machines.

Telnet terminal access: The service terminal is connected to the router (Telnet Client) through an asynchronous serial port. The router is connected to the front-end machine (Telnet Server) through the network. The application services run on the front-end machine. The front-end machine interacts with the router through the standard Telnet method. Then establish a data channel between the terminal and the front-end machine.

ETelnet terminal access: The service terminal is connected to the router (ETelnet Client) through an asynchronous serial port. The router is connected to the front-end machine (ETelnet Server) through the network. The application services run on the front-end machine. The front-end machine communicates with the router through a specific encrypted Telnet method. Interaction, and then establish a data channel between the terminal and the front-end machine.

SSH terminal access: The business terminal is connected to the router (secure shell) through an asynchronous serial port. The router is connected to the front-end machine (SSHServer) through the network. Application services run on the front-end machine. The front-end machine interacts with the router through standard SSH, and then Establish a data channel between the terminal and the front-end machine.

RTC terminal access: The initiator of the RTC is a router, and the receiver is also a router. RTC terminal access is another typical application of terminal access. It establishes a connection between a local terminal device and a remote terminal device through a router, completes data interaction, and implements data monitoring functions.

In asynchronous RTC mode (RTC currently only supports asynchronous mode), the monitoring terminal in the data center and the remote monitored terminal are connected to the router through an asynchronous serial port, and the routers exchange data through the IP network.

Generally speaking, the router connected to the monitoring device acts as the initiator (RTC Client). The monitoring device can initiate the connection at any time to obtain the data of the monitored device. The router connected to the monitored device acts as the receiver (RTC Server), and receives the connection request of the monitored device at any time to send the monitored data.

The above is the news sharing from the PASSHOT. I hope it can be inspired you. If you think today' s content is not too bad, you are welcome to share it with other friends. There are more latest Linux dumps, CCNA 200-301 dumps, CCNP Written dumps and CCIE Written dumps waiting for you.

[glisteningblack]

Ssh隧道详解，ssh端口转发详解

Ssh隧道详解，ssh端口转发详解

比如，端口转发可用于将两台电脑连到一起玩游戏，或当您不在家的时候也能察看家里的摄像机。为此小编就来跟大家分享一个实用性比较强的端口转发软件——花生壳，顺便为大家分享一些端口映射的相关资讯。 Server上的forwardingPort将会被监听，访问sshServer上的forwardingPort，就相当于访问targetIP的targetPort，ssh隧道建立在本机与sshServer之间。工作原理是这样的, 本地机器上分配了一个 socket 侦听 port 端口, 一旦这个端口上有了连接, 该连接就经过安全通道转发出去, 根据应用程序的协议可以判断出远程主机将和哪里连接.

：表示ssh隧道对应的转发端口将监听在主机的所有IP中，不使用"-g选项"时，转发端口默认只监听在主机的本地回环地址中，"-g"表示开启网关模式，远程端口转发中，无法开启网关功能。这是因为该 Jupyter 程序作为当前终端的子进程，在用户终端关闭的时候将收到一个 hangup 信号，从而被关闭。生活中，很多网友反映有些端口号被屏蔽，不能正常长使用。鸿哥在这里，用映射3389端口号为例，来进行演示设置。

这时候，可以通过在你的水星路由器中，设置动态DNS功能，来解决这个问题。如果你在使用端口转发时遇到问题，尝试禁用所有的桌面防火墙。如果电脑中有一些文件、软件，需要让外网的其他人访问，那么这时候可以使用路由器中的端口映射功能来实现。其实，它是一种��络连接术语，计算机在局域网内的时候，外网和内网的计算机节点连接通信，从而会出现不支持的内网穿透。

目前能实现端口转发的工具大致有��rinetd、SSH、iptables、nginx、haproxy，其中rinetd配置最为简单，但不支持UDP转发，并且该软件已经好几年未更新，如果您服务器上已经安装了nginx，不妨用nginx做端口转发。网络的出现，给人们的生活带来了精彩，让人们在任何地方都能实现远程办公、远程管理、远程监控等。当设置动态DNS后，外网的用户，就可以使用域名来远程访问你水星路由器了，而不必关心WAN口IP地址变法问题了。内网，顾名思义就是内部建立的局域网，比如一家企业有多台计算机，他们利用不同的网络布局，将多台计算机等设备连接起来，形成一个共享的网络。

[kulibinpro-blog]

Sshuttle

apt-get install sshuttle

sudo sshuttle -r username@sshserver 0.0.0.0/0 https://habrahabr.ru/post/318694/

[passhotdumps]

Quickly understand terminal access technology

Today, I will tell you about terminal access technology. Terminal access means that the terminal device is connected to the router, and the data communication between the terminal device and other terminal devices is completed through the router.

The terminal access implemented by the router is divided into two types: the terminal access initiator and the terminal access receiver.

The terminal access initiator is the party that initiates the TCP connection request, as the client of the TCP connection, generally a router;

The terminal access receiver is the one responding to the TCP connection request. As the server of the TCP connection, it can be a front-end processor or a router.

Whether the router is the initiator or the receiver, as long as the TCP connection is established, the data stream on the terminal device can be transparently transmitted to the opposite end of the TCP connection.

Generally speaking, there are five types of terminal access:

1

TTY terminal access: the initiator is the router, and the receiver is the front-end processor. The service terminal is connected to the router through the asynchronous serial port, and the router is connected to the front-end processor through the network. The application service runs on the front-end processor. The front-end processor interacts with the router through the ttyd program, and pushes the business screen to the service terminal through the router. The router is responsible for the transparent transmission of data between the connected service terminal and the front end processor.

2

Telnet terminal access: The service terminal is connected to the router (Telnet Client) through the asynchronous serial port, and the router is connected to the front-end processor (Telnet Server) through the network. The application service runs on the front-end processor. The front-end computer interacts with the router through standard Telnet. Then establish a data channel between the terminal and the front end processor.

3

ETelnet terminal access: The service terminal is connected to the router (ETelnet Client) through the asynchronous serial port, and the router is connected to the front-end processor (ETelnet Server) through the network. The application service runs on the front-end processor, and the front-end processor communicates with the router through a specific encrypted Telnet. Interaction, and establish a data channel between the terminal and the front end processor.

4

SSH terminal access: The business terminal is connected to the router (secure shell) through the asynchronous serial port, the router is connected to the front-end computer (SSHServer) through the network, and the application service runs on the front-end computer. The front-end computer interacts with the router through standard SSH, and then Establish a data channel between the terminal and the front-end processor.

5

RTC terminal access: The RTC initiator is a router, and the receiver is also a router. RTC terminal access is another typical application of terminal access. It establishes a connection between a local terminal device and a remote terminal device through a router, completes data interaction, and realizes data monitoring functions.

In asynchronous RTC mode (RTC currently only supports asynchronous mode), the monitoring terminal in the data center and the remote monitored terminal are connected to the router through an asynchronous serial port, and the routers exchange data through the IP network.

Generally speaking, the router connected to the monitoring device acts as the initiator (RTC Client), and the monitoring device can initiate a connection at any time to obtain the data of the monitored device. The router connected to the monitored device acts as the receiver (RTC Server), which can receive the connection request of the monitored device at any time to send the monitored data.

The above is the news sharing from the PASSHOT. I hope it can be inspired you. If you think today' s content is not too bad, you are welcome to share it with other friends. There are more latest Linux dumps, CCNA 200-301 dumps, CCNP Written dumps and CCIE Written dumps waiting for you.