I have a Cisco 837 router with a dialer interface that I need to protect from the external. Its Ip address is dynamic but associated to it there is an unambiguous fully qualified domain name that can be resolved via dynamic Dns.
How can I specify this in an access list? I.e.:
- "access list 110 deny ip any host " is inappropriate, as the Ip address may change in the future
- "access list 110 deny ip any host " doesn't change the situation as the is resolved at the moment it goes in the configuration and remains outdated when it will change.
So, how can I specify a dynamic hostname in an access list in Cisco Ios to solve my purpose?
Thank you in advance! Best regards. Diego.