Linking Two Networks - Lancom 821+ Manual

LANCOM 821+ – LANCOM 1711+ VPN – LANCOM 1721 VPN
Chapter 5: Linking two networks

5 Linking two networks

With the network interconnection (also known as LAN to LAN coupling) of the
LANCOM Router, two local networks are linked.
The LAN to LAN coupling can be realized in principle in two different ways:
Always configure both sides
Both routers involved in the network interconnection must be configured.
Care must be taken to ensure that the configuration information provided
matches.

A setup wizard handles the configuration of the connection in the usual con-
venient manner.
Security aspects
You must, of course, protect your LAN against unauthorized access. A
LANCOM Router therefore offers a whole range of security mechanisms that
can provide an outstanding level of protection:
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VPN: For coupling via VPN, the connection between both LANs is estab-
lished over a specially secured connection through the public Internet. A
router with VPN support is required in both LANs.
ISDN: For coupling via ISDN, a direct connection between both LANs is
established over an ISDN connection. A router with ISDN interface is
required in both LANs.
The following instructions will assume that LANCOM Router devices
are being used on both sides. A network interconnection may also be
realized with routers from other manufacturers. A mixed setup usually
requires more extensive configuration measures for both devices,
however. Please refer to the reference manual for more information in
this regard.
VPN: Network couplings via VPN transmit data by IPSec. The data are
encrypted by AES, 3-DES, Blowfish or CAST encryption algorithms.
ISDN: For network couplings via ISDN, the connection password, the
checking of the ISDN number and the callback function ensure the secu-
rity of the connection.