explain remote access via ssh on switches and routers

Secure Shell

(SSH) is a network protocol that establishes a secure terminal emulation connection to a router or other networking device. SSH encrypts all information that passes over the network link and provides authentication of the remote computer. SSH is rapidly replacing Telnet as the remote login tool of choice for network professionals.

Full Answer

What is SSH on Cisco routers and switches?

Short and complete guide to configure SSH on Cisco router and switch for secure remote connection. The Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network.

How do I configure SSH remote access on a switch?

The line level access (for remote access) should be configured for only SSH, but the default supports all access methods. Go to the lines using line vty 0 4 or higher depending on the version and type of platform (most IOS switches support 16 virtual terminal lines, so that would be line vty 0 15 ).

What is SSH and how to use SSH?

SSH is a security mechanism, which can be used to access the privilege and configuration mode of a Router and a Switch from a remote location to perform the required action.

Which SSH protocol should I use for remote access?

Remote access should use the more secure option for remote access: SSHv2 over Telnet; SCP (Secure Copy Protocol) over FTP or TFTP; HTTPS over HTTP. The foundational security for each is based on the configuration for SSHv2.

What is SSH in switch?

SSH is a secure method for remote access to your router or switch, unlike telnet. SSH requires a RSA public/private key pair. SSH version 2 is more secure than version 1. Make sure you have an IOS image that supports crypto features, otherwise you can't use SSH.

What is SSH access router?

SSH stands for “Secure Shell” and it is an enhanced security encryption algorithm for modern routers made by a community for developers. You won't be able to enable SSH access or SSH connections in the router's settings page, so it requires downloading a third-party SSH client, such as Putty.

Can you SSH into a Cisco switch?

From the switch, if you do 'sh ip ssh', it will confirm that the SSH is enabled on this cisco device. After the above configurations, login from a remote machine to verify that you can ssh to this cisco switch. In this example, 192.168. 101.2 is the management ip-address of the switch.

Can you SSH from a Cisco router?

A quick and simple activereach Technical Tutorial Video to demonstrate how you can SSH from a Cisco router to an SSH server. This “daisy-chaining” technique is useful to make connections to devices where access may be limited by IP address, or from machines that do not have a local SSH client installed.

What is SSH and how does it work?

SSH or Secure Shell is a network communication protocol that enables two computers to communicate (c.f http or hypertext transfer protocol, which is the protocol used to transfer hypertext such as web pages) and share data.

How does SSH protocol work?

SSH protocol uses public key cryptography to authenticate the server, meaning the server sends its public key to the client for confirmation. The client is able to authenticate the server by comparing this host key against a local database or by receiving the verification of a Certified Authority (CA).

What port does SSH use?

port 22By default, the SSH server still runs in port 22.

How do switches and routers work in a network?

Just as a switch connects multiple devices to create a network, a router connects multiple switches, and their respective networks, to form an even larger network. These networks may be in a single location or across multiple locations.

When using SSH to remote access a Cisco router can you see the terminal password Why or why not?

Cisco 5. When using SSH to remotely access a Cisco router, can you see the terminal password? Why or why not? No, because it is Linux based and they do not show the passwords so you are not able to even guess it.

Which two steps are required before SSH can be enabled on a Cisco router?

Which two steps are required before SSH can be enabled on a Cisco router? (Choose two.) Give the router a host name and domain name. Create a banner that will be displayed to users when they connect. Generate a set of secret keys to be used for encryption and decryption.

Which type of access is secured on a Cisco router?

3. Which type of access is secured on a Cisco router or switch with the enable secret command? The enable secret command secures access to the privileged EXEC mode of a Cisco router or switch.

What feature of SSH makes it more secure?

SSH makes it possible to bypass password protection on critical servers when a user logs in from a host that has authenticated itself by sharing a public key and a signature using the associated private key.

How do I SSH into TP Link router?

1 AnswerEnsure SSH Enabled. Goto the Services tab and the Services sub-tab on the Web Interface. Enable "SSHd" is under the section titled "Secure Shell" ... Enable Remote Access. Goto the Administration tab and the Management sub-tab on the Web Interface. Enable "SSH Management" under the section titled "Remote Access"

How do I connect to SSH?

How to Connect via SSHOpen the SSH terminal on your machine and run the following command: ssh your_username@host_ip_address. ... Type in your password and hit Enter. ... When you are connecting to a server for the very first time, it will ask you if you want to continue connecting.More items...•

How do I SSH into my Asus router?

Wired connect your router and computer and then log in the router setting page. Step2. Find [Service]>[Enable SSH]. Click the dropdown list and choose [LAN only] or [LAN & WAN].

How do I enable SSH?

Activate or deactivate the SSH serversudo rm -f /etc/ssh/sshd_not_to_be_run sudo systemctl enable ssh sudo systemctl start ssh.sudo mv /etc/init/ssh.conf.back /etc/init/ssh.conf sudo start ssh.sudo systemctl stop ssh sudo systemctl disable ssh.sudo stop ssh sudo mv /etc/init/ssh.conf /etc/init/ssh.conf.back.

What is SSH authentication?

authentication [5]. SSH is a network protocol that provides a safe way for administrators to

Why is it important to configure a router?

Therefore, it is important to properly configure routers, as this will help to resist attacks and maintain the security and confidentiality of network traffic. Using Telnet for accessing a router remotely is not secure enough. The aim of this paper is to demonstrate that using Secure Socket Shell protocol (SSH) to remote login a router is more secure. Cisco packet tracer simulation has been used for configure the router. The simulation showed that The SSH is provides a strong authentication and encryption, preserves the confidentiality and privacy of communications.

What does a router inspect?

connected computers [ 2]. The router inspects the destination address when a data packet

What is a private network?

INTRODUCTION A private network that carries sensitive data between local computers requires proper security measures to protect the privacy and integrity of the traffic. When such a network is connected to other networks, or when telephone access is allowed into that network, the remote terminals, phone lines, and other connections become extensions to that private network and must be protected accordingly. In addition, the private network must be protected from outside attacks that could cause loss of information, breakdowns in network integrity, or breaches in security. The goal of this work was to take an established and clearly demarked security perimeter and extend it. Extensions could be from the internal network to homes or hotel rooms over phone lines or to users on other hosts on another, outside network, over an external network. The extension of the security perimeter is done for selected services, under well-understood controls, without compromising security. The initial i...

How is a network exposed to attackers?

packet along that path. The network may be exposed to attackers by a security hole in a

What is the first step in protecting the network?

significant first step in protecting the network is protecting routers at the network perimeter.

How to access PPK file on remote machine?

Navigate, via the left-hand pane, down to Connection –> Auth. Here you need to click the Browse button and select the .PPK file you saved and brought over to your remote machine.

Why is it important to connect to the internet from a hotspot?

Connecting to the internet from Wi-Fi hotspots, at work, or anywhere else away from home, exposes your data to unnecessary risks. You can easily configure your router to support a secure tunnel and shield your remote browser traffic—read on to see how.

What is and Why Set Up a Secure Tunnel?

Let’s lay out a couple different scenarios that involve you using the internet to illustrate the benefits of secure tunneling.

How to secure Firefox?

The configuration process for Firefox translates to practically any application you’ll need to plug in SOCKS information for. Launch Firefox and navigate to Options –> Advanced –> Settings. From within the Connection Settings menu, select Manual proxy configuration and under SOCKS Host plug in 127.0.0.1 —you’re connecting to the PuTTY application running on your local computer so you must put the local host IP, not the IP of your router as you’ve been putting in every slot so far. Set the port to 80, and click OK.

How to get a PuTTY key?

Download the full PuTTY pack and extract it to a folder of your choice. Inside the folder you’ll find PUTTYGEN.EXE. Launch the application and click Key –> Generate key pair. You’ll see a screen much like the one pictured above; move your mouse around to generate random data for the key creation process. Once the process has finished your PuTTY Key Generator window should look something like this; go ahead and enter a strong password:

Does DD-WRT have SSH?

Both Tomato and DD-WRT have built-in SSH servers. This is awesome for two reasons. First, it used to be a huge pain to telnet into your router to manually install an SSH server and configure it. Second, because you’re running your SSH server on your router (which likely consumes less power than a light bulb), you never have to leave your main computer on just for a lightweight SSH server.

Can you use SSH tunnel on Wi-Fi?

Although we used Wi-Fi in our example you could use the SSH tunnel to secure a hardline connection to, say, launch a browser on a remote network and punch a hole through the firewall to surf as freely as you would on your home connection.

What is SSH?

Secure Shell, sometimes referred to as Secure Socket Shell, is a protocol which allows you to connect securely to a remote computer or a server by using a text-based interface.

What is SSH client?

An SSH client is an application you install on the computer which you will use to connect to another computer or a server. The client uses the provided remote host information to initiate the connection and if the credentials are verified, establishes the encrypted connection.

What is needed to accept SSH connections?

In order to accept SSH connections, a machine needs to have the server-side part of the SSH software toolkit.

How to get remote desktop on Windows 7?

You can find it in a couple of different ways: For Windows 7, click on Start -> All Programs, go to the ‘Accessories’ folder and click on Remote Desktop Connection.

What is the component of SSH?

On the server’s side, there is a component called an SSH daemon that is constantly listening to a specific TCP/IP port for possible client connection requests. Once a client initiates a connection, the SSH daemon will respond with the software and the protocol versions it supports and the two will exchange their identification data. If the provided credentials are correct, SSH creates a new session for the appropriate environment.

How to enable remote access in Windows 7?

Enabling Remote Access in Windows 7, 8, 10 and Windows Server Versions. Step 1: Allow Remote Connections. Step 2: Add Users to the List of Remote Users. How to Use the Remove Desktop Connection Client.

What is the protocol used to connect to a remote machine?

There are many ways to establish a connection with a remote machine depending on the operating system you are running, but the two most used protocols are: Secure Shell (SSH) for Linux-based machines. Remote Desktop Protocol (RDP) for Windows-based machines.

What is SSH on Cisco router?

The Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. The best-known example application is for remote login to computer systems by users.

What is SSH in network?

SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server. Common applications include remote command-line login and remote command execution, but any network service can be secured with SSH.

Does the default gateway include the mask?

Configuration of default gateway takes place in the configuration mode and the command does not include the mask for the ip.

Can you use static NAT on a router?

You can use static nat on your router for this issue. Your switch doesn't support to nat.

How does SSH work?

The way SSH works is by making use of a client-server model to allow for authentication of two remote systems and encryption of the data that passes between them.

What is the SSH key?

The SSH key command instructs your system that you want to open an encrypted Secure Shell Connection. {user} represents the account you want to access. For example, you may want to access the root user, which is basically synonymous for system administrator with complete rights to modify anything on the system. {host} refers to the computer you want to access. This can be an IP Address (e.g. 244.235.23.19) or a domain name (e.g. www.xyzdomain.com).

What are the advantages of SSH?

The significant advantage offered by SSH over its predecessors is the use of encryption to ensure secure transfer of information between the host and the client. Host refers to the remote server you are trying to access, while the client is the computer you are using to access the host. There are three different encryption technologies used by SSH: 1 Symmetrical encryption 2 Asymmetrical encryption 3 Hashing.

How is a symmetric key used in SSH?

Symmetric keys are used to encrypt the entire communication during a SSH Session. Both the client and the server derive the secret key using an agreed method, and the resultant key is never disclosed to any third party. The process of creating a symmetric key is carried out by a key exchange algorithm. What makes this algorithm particularly secure is the fact that the key is never transmitted between the client and the host. Instead, the two computers share public pieces of data and then manipulate it to independently calculate the secret key. Even if another machine captures the publically shared data, it won’t be able to calculate the key because the key exchange algorithm is not known.

How to establish a connection?

There are two stages to establishing a connection: first both the systems must agree upon encryption standards to protect future communications, and second, the user must authenticate themselves. If the credentials match, then the user is granted access.

When is asymmetrical encryption used?

Instead, it is only used during the key exchange algorithm of symmetric encryption. Before initiating a secured connection, both parties generate temporary public-private key pairs, and share their respective private keys to produce the shared secret key.

What ciphers are used for symmetric encryption?

A variety of symmetrical encryption ciphers exist, including, but not limited to, AES (Advanced Encryption Standard), CAST128, Blowfish etc. Before establishing a secured connection, the client and a host decide upon which cipher to use, by publishing a list of supported cyphers in order of preference. The most preferred cypher from the clients supported cyphers that is present on the host’s list is used as the bidirectional cypher.

Objective

The objective of this lab is to configure the switch for remote management such that the laptop PC residing on a remote network be used to login and manage it via ssh . To accomplish this, the following will be done:

Implementation

The following configuration commands will the required to configure a Cisco switch for remote management. The commands used here a for the lab represented in the network topology used here. However, the solution can be achieved in many different ways.

Verification

To verify that I have configured the Cisco switch for remote management via ssh, I try to access the switch using the laptop on the network 192.168.0.0/24 using ssh. Remember that both the laptop and the switch are on different networks. See the result below.

How to protect a switch from a MAC address?

The data plane for a switch must be protected against bogus Media Access Control (MAC) addresses, rogue devices attaching themselves to the switch and those trying to spoof addressing across the switch. One potential attack is to fill the layer 2 forwarding table with bogus MAC addresses. To help protect the forwarding table from bogus source MAC addresses, use port security, which locks down the ports to a specific number of source MAC addresses that can be seen on a port as well as which address are legal on a given port. If there are too many source MAC addresses or the wrong MAC addresses as sources, port security registers a violation. The default table size for a port that has port security enabled on it is one (one MAC address only), and the default violation is shutdown, which actually puts the port into an errdisabled state.

What is enable secret?

The enable secret uses a Message Digest 5 (MD5) hashing algorithm to encrypt the password in the configuration; the enable password does not. If the service password encryption command is used, the enable password and the line level password will be encrypted but with a much more simplistic method.

What is CoPP in router?

Control Plan Policing (CoPP) allows us to control those applications and others that are potentially disruptive to the control plane. (Even the lowly echo can be disruptive if there are too many being sent to the router or switch.) We use Modular QoS Command Line Interface (MQC) to configure a policy that would police traffic destined to the router or switch itself. Use the class maps to define the different types of traffic heading to the router or switch; next, in the policy map, define policers to limit how much can be sent and apply to the control plane under the global control-plane command to get to the control plane sub-configuration mode. Finally, apply the service policy to the control at that point.

Why is SNMPv3 used?

SNMPv3 provides secure access to devices because it authenticates and optionally encrypts packets over the network. Use Access Control Lists (ACLs) to limit who can access the device remotely.

How to lock out a user after a failed login?

Using the Login Password Retry Lockout feature is also recommended. This allows you to lock out a local user account after a specific number of failed attempts to log into the system. Use the aaa local authentication attempts max-fail < max-attempts > command to enable this feature. Note that users that are configured for level 15 privilege are not affected by this feature.

Do firewalls help with IPS?

Firewalls will help along with Intrusion Prevention Systems (IPS), but there are additional steps we can take to harden the routers and switches within our network. The National Security Agency (NSA) has guidelines for hardening devices for use with the U.S. federal government.

Is SCP secure?

Secure Copy (SCP) is also now available for file transfer, which is based on SSH and therefore more secure. To enable the HTTPS server, use the ip http secure-server command, confirm that no ip http server is configured to disable the non-secure version.

Introduction

See more on cisco.com

Prerequisites

Optional Configuration Sets

Debug and Show Commands

Sample Debug Output

Tips