Network Connections
40
Internet Failover
Internet failover is available on SnapGear gateway appliances only.
SnapGear appliances are designed with the real Internet in mind, which may mean
downtime due to ISP equipment or telecommunications network failure. Failures can be
caused by removing the wrong plug from the wall, typing in the wrong ISP password or
many other reasons. Regardless of the cause of a failure, it can potentially be very
expensive.
When the main Internet connection fails and the backup connection (failover connection)
is started, VPN connections are restarted and dynamic DNS services are advised of the
new IP address.
To utilize the failover capabilities of your SnapGear appliance, you must:
•
Enable your primary Internet connection for failover
•
Set up a secondary backup Internet connection
SnapGear appliance models with a DMZ port (SME570, SME575) can use broadband
(cable/DSL/direct connection) as both their primary and backup connections. Other
models may only use broadband as their primary connection and narrowband (dial-up
modem) as their backup connection.
Enable the primary connection for failover
Set up your primary broadband Internet connection as described in the
Internet
section of
this chapter. From the
Connections
menu, select
Edit failover parameters
from the
Configuration
pull down box.
The SnapGear appliance determines whether an Internet connection is up by listening for
responses to
ping
(ICMP echo request) packets sent to a host on the Internet. Ensure
you choose a host on the Internet that can be contacted reliably and responds to pings.
You can check whether you can ping a host under
Diagnostics
->
Network Tests
->
Ping Test
.
