Perle Systems Technical Notes
Using Access Control Lists
Access lists are vital to security.
Perle supports Management Access List (ACL) to give administrators the ability to restrict which workstations have access to the management interface of Perle devices. By specifying which IP addresses are allowed, the Perle can block attempted access from unauthorized workstations that are not specified in the Access List.
Application types by IP port number can also be restricted. As an example, an administrator could allow only encrypted type applications such as SSH and HTTPS access (IP ports 22 and 443) and disallow an attempted access via Telnet (IP port 23).

Perle Products that support Access Control Lists
Image by Stuart Miles at FreeDigitalPhotos.net