What is the recomended method to secure the access to Internet zone devices (router/switch) with public IPs? SSH enabled to access via Internet and is configured as transport for line vty with firm owned public ip ACL, even then the sitch/router responds to telnet with switch/router > via internet.
line vty 0 4
access-class 23 in --> Firm owned puble IPs
exec-timeout 20 0
transport input ssh
line vty 5 15
ip addtress 18.104.22.168 255.255.255.248
Now from Internet (not from Firm IPs) with telnet test:
What is the procedure, so that it will not give any prompt form outside/firm owned public IPs..?