Information
Specify the version of Secure Shell (SSH) to be run on a router
SSH Version 1 has been subject to a number of serious vulnerabilities and is no longer considered to be a secure protocol, resulting in the adoption of SSH Version 2 as an Internet Standard in 2006.
Cisco routers support both versions, but due to the weakness of SSH Version 1 only the later standard should be used.
Solution
Configure the router to use SSH version 2
hostname(config)#ip ssh version 2
Impact:
To reduce the risk of unauthorized access, organizations should implement a security policy to review their current protocols to ensure the most secure protocol versions are in use.