Operation Manual

Cerberus P 6381-2
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Add or Modify a Virtual Server Entry
Service Port - The numbers of External Ports. You can enter a service port or a range of
service ports (the format is XXX - YYY, XXX is Start port, YYY is End port).
IP Address - The IP address of the PC running the service application.
Protocol - The protocol used for this application, either TCP, UDP, or All (all protocols
supported by the router).
Status - Select Enabled or Disabled for this entry on the pull-down list.
Common Service Port - Some common services already exist in the pull-down list.
Click the Save button to save this settings.
Forwarding / Port Triggering
Some applications require multiple connections, like Internet games, video conferencing,
Internet telephoning and so on. These applications cannot work with a pure NAT router. Port
Triggering is used for some of these applications that can work with an NAT router. Once
configured, operation is as follows: A local host makes an outgoing connection to an external
host using a destination port number defined in the Trigger Port field. The router records this
connection, opens the incoming port or ports associated with this entry in the Port Triggering
table, and associates them with the local host. When necessary the external host will be able
to connect to the local host using one of the ports defined in the Incoming Ports field.
Trigger Port - The port for outgoing traffic. An outgoing connection using this port will Trigger
this rule.
Trigger Protocol - The protocol used for Trigger Ports, either TCP, UDP, or All (all protocols
support by the router).
Incoming Ports - The port or port range used by the remote system when it responds to the
outgoing request. A response using one of these ports will be forwarded to the PC which
triggered this rule.