Port Forwarding - Gigaset SE681 WiMAX User Manual

Port Forwarding

The Gigaset SE681 WiMAX comes with the NAT (Network Address Translation) function,
which is always activated in Router operating mode. With address mapping, multiple
users in the local network can access the Internet via the public IP address. All the local
IP addresses are assigned to the router's public IP address by default. All IP addresses of
PCs in the local network are converted to the router's public IP address when accessing
the Internet.
Most Internet applications can be executed behind the NAT firewall without any prob-
lems. However, some applications - such as Internet games - require users in the Inter-
net to send requests to users in the local network so that the players can communicate
with each other. Sometimes these applications also require several ports to communi-
cate through. Such applications do not work if NAT is active.
Using port forwarding (the forwarding of requests to particular ports) the router is
forced to send requests from the Internet for a certain service, for example a game, to
the appropriate port(s) on the PC on which the game is running. If you configure Port
Forwarding, the Gigaset SE681 WiMAX outwardly assumes the role of the server. It
receives requests from remote users under its public IP address and automatically redi-
rects them to local PCs. The private IP addresses of the servers on the local network
remain protected.
Internet services are addressed via defined port numbers. The Gigaset SE681 WiMAX
needs a mapping table of the port numbers to redirect the service requests to the serv-
ers that actually provide the service. Port Forwarding has to be configured for this pur-
pose.
ì
Open the Advanced Settings tab and on the Internet menu select Port Forward-
ing.
ì
Define the list of services for which you want requests from the Internet to be for-
warded.
Important services are already included in the Predefined applications selection field.
The list can hold up to 20 entries.
The IP addresses of the PCs for which you set up port forwarding must
remain unchanged. If the IP addresses of the PCs are assigned via the
i
DHCP server of the Gigaset SE681 WiMAX, you must select the option
Never expires as the Lease time when configuring the DHCP server or
assign static IP addresses to the PCs, see "Configuring the DHCP server" on
page 37.
i
This function is not available in Bridge operating mode, see "Configuring
Internet access" on page 33.
Advanced Settings
35