The RPC portmapper service listens on a static port (TCP or UDP port 135). It converts the RPC program numbers into TCP/IP (or UDP/IP) protocol port numbers.
Some Microsoft applications and services such as Outlook, Exchange, and the Messenger Service also use this service and listen on both TCP and UDP port 135 for endpoint mapping / communications. For management and security concerns, the purpose of this feature (filter of RPC_portmapper) is to filter the TCP/UDP port 135 for prohibition of some unwanted services.
Вот пример настройки данного функционала:
Код:
DES-3526:admin#config filter RPC_portmapper 1 state enable
Command: config filter RPC_portmapper 1 state enable
Success.
DES-3526:admin#show filter RPC_portmapper
Command: show filter RPC_portmapper
Enabled ports: 1