Dynamic ACL Updating
Dynamic ACL Updating is a type of access control list, or IP traffic filtering feature, that relies on telnet connectivity, authentication and extended ACLs. This can be used in conjunction with other standard access lists and static extended access lists.

Network routers are configured to apply extended ACLs to block traffic from users who want to access the router without the use of telnet and authentication. However, with Dynamic ACL Updating on the router, it reconfigures the interface’s existing IP access list to permit designated users to reach their designated networks or host(s) and reconfigures the interface back to its original state when the user has gained access. Dynamic ACL Updating permits traffic for a particular period of time.

Advantages of Dynamic ACL Updating
Some of the security advantages of Dynamic ACL Updating include:

• The use of an authentication mechanism for individual users.
• Reduction of the opportunity for network break-ins by network hackers.
• Potential reduction of the amount of router processing that is required for ACLs.
• Simplified management in large internetworks.
• Creation of dynamic user access through a firewall, without compromising other configured security restrictions.