Multitech RouteFinder MTASR3, User Manual, Page: 49 / 113

Chapter 4 - RASFinder Software
MTASR3-200 49
Add/Edit IP Port Filter dialog box, the protocol that is going to be filterred is TCP, the physical port on
which the filtering is going to take place is the LAN port, the protocol port is telnet which translates
into protocol port number 0023 in the filtering list window, and the filter type is Filter on Destination
Port which means to drop all IP packets whose destination protocol port is telnet.
Address filtering uses the IP address in the IP Address field (example, packets with address
192.168.2.40), applies filtering to the physical port listed in the Physical Port field (LAN), and if the
Filter Type is Filter on Destination Address that means that all packets with an IP address of
192.168.2.40 that are destined for the LAN port are blocked.
ICMP filtering provides separate filtering support for specific kinds of received ICMP packets. ICMP
filtering is used in IP networks as an internal protocol for nodes to exchange control and diagnostic
information. Applications normally do not use ICMP filtering for any purpose.
You can select ICMP filtering on your LAN or WAN ports and the type of filtering on each port by
choosing the filtering type from the ICMP Packet Types list.