ccna 200-301 official cert guide ebook

ccna 200-301 official cert guide ebook.SSH version 2 (SSHv2): provides better security using Diffie-Hellman key exchange and strong integrity-checking message authentication codes (MACs).The default setting for SSH is SSH version 1.99. This is also known as compatibility mode and is only used to indicate that the server supports both SSHv2 and SSHvlo However, best practice is to enable SSHv2 onlyo To change from compatibility mode to the specified mode, you can use the ipsshversion {1 | 2} global configuration mode command.The amount of time the router waits for the SSH client to respond during the SSH negotiation phase can be configured in global configuration mode with the ipsshtime-out seconds command, which defaults to 120 seconds. This value is not the same as the exec-timeout value, which is the amount of time required for SSH to authenticate the user. After the EXEC session begins, the standard exec-timeoutof the vty application configuration is appliedBy default, the user has three chances to log in before disconnecting. The number of consecutive SSH logins can be configured in global configuration mode using the command ip ssh authentication-retries integer.34 Chapter 2 Protecting Network DevicesTo verify the settings of these SSH optional commands, use the show ipssh command. After SSH is configured, the SSH client needs to be connected to an SSH-enabled router.2.1.4.4 Connecting to an SSH-enabled routerThere are two different ways to connect to an SSH-enabled router.Connect to an SSH-enabled router using the ssh command in privileged EXEC mode. The Cisco router can act as both an SSH server and an SSH client that connects to other SSH-enabled devices. By default, when SSH is enabled, both of these features are enabled on the router as well. As a server, the router can accept SSH client connections; as a client, the router can connect to other its SSH-enabled routers via SSH.Connect using public, commercial SSH clients running on the host computer, such as PuTTY, OpenSSH, and TeraTerm guest