Virtual Server (Port Forwarding); Port Filter - TIPTEL 3022 office Installation Manual

Virtual server (Port Forwarding)

Enter here name and IP address of a local PC. As port, enter the port address of the
desired server service (for example port 21 for an FTP server). Via the item "protocol",
you can determine, which protocols shall be routed to the chosen server. The setting
"VPN/PPTP" may only be active for one server.
Function:
For data packets which are transmitted from the LAN (local net) to the WAN (DSL ac-
cess), the IP sender address (IP address of the PC) must be replaced with the IP
sender address of your telephone system. This is necessary, because your tele-
phone system can only be addressed from the WAN via this IP address. In order that
the response can again be assigned to the correct PC, a port will be added to the
sender address.
However, because of this it is not offhand possible to approach a certain PC with a
certain service from the WAN. This will be rendered possible via the function "virtual
server": A port will be fixed associated to the desired IP address (PC) in the LAN.
Now the IP sender address of this PC will always be replaced with the IP sender ad-
dress of your telephone system with the programmed port. Incoming enquiries on
this port will then always be directed to this PC.
Note: The IP address of the relevant PC should be fixed and may not be included
in the range of IP addresses of the DHCP server. For security reasons, you should
install a local firewall on this computer.

Port filter

Here you can enable a port filter for going IP packets for the protocols TCP or UDP. If
you wish to block only certain services for the users (for example FTP with port 21),
you have to select "block ports" and enter port 21 with protocol TCP into the list. If
you wish to block all and allow only certain services, you have to select "allow ports".
Configuration: Internet
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