SnapGear 1.7.8 Manuel D’Utilisation

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3.  Connecting to the Internet 
This chapter provides step-by-step instructions for connecting your SnapGear appliance 
to your Internet Service Provider (ISP). 
The SnapGear appliance provides secure Internet access using its robust embedded 
firewall. The SnapGear appliance has an IP masquerading feature, which means that 
users on your local network can see the outside world; however the outside world cannot 
see inside your local network. This shields your network from intruders and also allows 
you to filter packets (see Chapter 6, Firewall) to prevent unwanted traffic to/from your 
network. 
The SnapGear appliance can connect to the Internet using an external dialup analog 
modem, an ISDN modem, a permanent analog modem, a cable modem or DSL link as 
shown in the following figure: 
 
Figure 3.1 Internet connection 
Physically connect modem device 
The first step in connecting your office network to the Internet is to physically attach your 
SnapGear appliance to the modem device. For analog modems, attach the modem serial 
cable to one of the SnapGear appliance’s serial ports (i.e. COM1COM2). For digital 
connections (e.g. cable, DSL), plug the cable into the Internet port. 
Warning 
To connect to an ISDN line, the SnapGear appliance requires an intermediate device 
called a Terminal Adapter (TA). A TA connects into your ISDN line and has either a serial 
or Ethernet interface that is connected to your SnapGear appliance. Do NOT plug an 
ISDN connection directly in to your SnapGear appliance. 
Connecting to the Internet 
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