Specifications

Forwarding Profiles
AVM Access Server – 5 AVM Access Server Concepts and Functional Principles 75
communicating with Internet hosts. Because only requested data is
forwarded into the LAN, the private LAN is protected against unautho-
rized access from the Internet.
The AVM Access Server’s use of IP masquerading provides the follow-
ing advantages:
Each time the connection to the Internet Service Provider is re-
established after an inactivity timeout, the Access Server is
assigned a new IP address. Thanks to IP masquerading, the com-
puter’s routing table does not need to be updated each time the
official IP address changes. The IP masquerading function always
substitutes the current official IP address for the source address
of packets traveling from the LAN to the Internet.
By default, IP masquerading prohibits all incoming TCP connec-
tions. Incoming packets that have not been requested by an
application in the LAN are discarded. This makes the local net-
work more secure.
Forwarding Profiles
When IP masquerading is active, forwarding profiles can be used to for-
ward requests from the Internet to specific servers in the LAN, such as
web, e-mail or FTP servers. A forwarding profile consists of one or more
forwarding rules. These rules specify which IP packets are forwarded to
which servers in the LAN—in other words, which services are accessi-
ble from outside.
To create or edit forwarding profiles, select “Security / Forwarding pro-
files” in the object tree of the AVM Access Server window. To activate
forwarding for Internet connections, select the “Internet” folder, click
the “Gateway Services” tab, and select the desired forwarding profile.
The AVM Access Server provides a pre-defined forwarding profile
named “Gateway Services” in the “Security / Forwarding profiles” fold-
er. This profile contains deactivated forwarding rules for common Inter-
net services. To permit access from the Internet to certain local servic-
es, you must activate the corresponding rules in this profile. If the
desired service is provided by the same computer on which the AVM
Access Server is installed, use the address 0.0.0.0 as the new destina-
tion to which the packets are forwarded. If the desired service is pro-
vided by a different computer in the LAN, enter that computer’s IP ad-
dress as the new destination to which the packets are forwarded.