What Does Port-to-Application Mapping Mean?
Port-to-application mapping (PAM) is a Cisco IOS Firewall feature that allows users to create customized Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) port numbers for network services or applications. PAM establishes a table of default port-to-application mapping information at firewalls using the respective port information. It also supports host or subnet port mapping, allowing users to apply PAM to a single host or subnet using a standard access control list.
Techopedia Explains Port-to-Application Mapping
Information in a PAM table serves as a default mapping for traffic passing through firewalls. These tables are capable of identifying applications associated with port numbers, including services running on non-standard ports. The mapping information provided by entries in the PAM table includes system-defined port mapping, user-defined port mapping and host-specific port mapping.
By using host-specific port mapping, users can use the same port number for different services on different hosts. For example, it is possible to map port 8000 with Hypertext Transfer Protocol (HTTP) services for one host and map the same port with the telnet service for another host. These mappings permit the users to apply PAM to specific subnets when they run services using port numbers different from those specified in the default mapping information.
The ip port-map configuration command is used in establishing the port-to-application mapping. The no form of this command deletes the user-defined PAM entries.