[Cisco Router] #Cisco #IOS #CLI #SSH #Networking

ssh.md

Enable SSH and change SSH Port on a Cisco Router

1. Define a domain name (plus hostname) on the router

    Router# conf t
    (config)# hostname *exampleRouter*
    (config)# ip domain-name *example.com*
   

2. Create crypto key (certificate)

   I would choose a 1024 key size out of personal taste. This process might take time on a slow device.

    (config)# crypto key generate rsa general-keys modulos [360-2048]
    (config)# ip ssh version 2
    (config)# end
   

3. Create an access-list so we can block incoming requests on port 22 and allow those upon the port we want tu use (example: 2233)

    (config)# ip access-list ex denySSH
    (config-ext-nacl)# 10 deny tcp any any eq 22
    (config-ext-nacl)# 20 permit tcp any any eq 2233
    (config-ext-nacl)# end
   

4. Apply SSH connection type to router so it can authenticate using the router's local database.

    (config)# config line vty 0 4
    (config-line)# access-class denySSH in
    (config-line)# rotary 1
    (config-line)# transport input ssh
    (config-line)# login (authentication) local 
    (config-line)# end
    (config)# end
   

5. Save running config...

    Router# copy startup-config running-config
   

Done!.

Nice video #1

Nice video #2