Configuring Wan Setup - Telkom ADSL 5100 Instruction Manual

5.5 Configuring WAN Setup

To change your TELKOM ADSL 5100's WAN remote node settings, click WAN. The screen differs
by the encapsulation.
5.5.1 PPP Half Bridge
When the PPP Half Bridge is enabled the TELKOM ADSL 5100 becomes invisible. The DHCP
server will duplicate the WAN IP address from the ISP to the local client PC. Only one PC is able
to access the Internet using half bridge mode.
Half bridge mode can only be used when a single IP address has been assigned by the ISP, it is
not suitable for services that provide multiple IP addresses. Half bridge mode is used when the
use of NAT or NAPT is not desired and there is a single computer attached to the TELKOM ADSL
5100 ADSL Gateway.
5.5.2 When to use Half Bridge mode
When using a separate firewall that will be protecting the network, half bridge mode will allow the
firewall to appear on the internet using the publicly accessible IP address assigned by the ISP.
This configuration will allow the dedicated firewall to have full control of the inbound and outbound
traffic and is the intended purpose for this mode.
Some applications that embed the IP address of the computer in the data are not compatible with
NAT or NAPT and so the computer requires a real public IP address. However the number of
applications that are not compatible with NAT/NAPT are reducing as developers address the
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