Example application: Secure Internet access via two DSL/ISDN combination routers

Two load-balancing default gateways that provide security for one another are to be the basis for operating the LAN at two DSL lines. On average, 50% of the LAN stations log in to router 1 and 50% to router 2. The failure of a router or the non-availability of a DSL connection is compensated for by the other router, which the takes over the full load.

Under normal operational circumstances, each router handles on average 50 % of users in the LAN (prio 250 for the DSL connection). Should a router or DSL connection fail, then the load is distributed to the other router (prio 100 for the DSL connection of the backup router). If both DSL connections fail, then the traffic is directed over the ISDN connections (each with backup prio 50, ISDN connections not illustrated).

Notes for the configuration of the virtual router

Router A     Router B  
  DHCP = On (10.1.1.x)     DHCP = On (10.1.1.x)
Router-ID = 1 Router IP = 10.1.1.1   Router-ID=1 Router IP=10.1.1.1
  Prio = 250     Prio = 100
  Backup prio = 50     Backup prio = 50
  Peer = DSL INTERNET     Peer = DSL INTERNET
  Comment: Main router f. Group 1     Comment: Backup router for Group 1
Router-ID = 2 Router IP = 10.1.1.2   Router-ID = 2 Router IP = 10.1.1.2
  Prio = 100     Prio = 250
  Backup prio = 50     Backup prio = 50
  Peer = DSL INTERNET     Peer = DSL INTERNET
  Comment: Backup router for group 2     Comment: Main router for group 2

www.lancom-systems.com

LANCOM Systems GmbH | A Rohde & Schwarz Company | Adenauerstr. 20/B2 | 52146 Wuerselen | Germany | E‑Mail info@lancom.de

LANCOM Logo