Comtrend Corporation CT-536+ User Manual page 34

PPP IP Extension
The PPP IP Extension is a special feature deployed by some service providers.
Unless your service provider specially requires this setup, do not select it.
The PPP IP Extension supports the following conditions:
Allows only one PC on the LAN
The public IP address assigned by the remote side using the PPP/IPCP protocol
is actually not used on the WAN PPP interface. Instead, it is forwarded to the
PC's LAN interface through DHCP. Only one PC on the LAN can be connected to
the remote, since the DHCP server within the ADSL router has a single IP
address to assign to a LAN device.
NAPT and firewall are disabled when this option is selected.
The ADSL router becomes the default gateway and DNS server to the PC
through DHCP using the LAN interface IP address.
The ADSL router extends the IP subnet at the remote service provider to the
LAN PC. That is, the PC becomes a host belonging to the same IP subnet.
The ADSL router bridges the IP packets between WAN and LAN ports, unless
the packet is addressed to the router's LAN IP address.
2. Click Next to display the following screen.
Enable IGMP Multicast checkbox: Tick the checkbox to enable IGMP multicast
(proxy). IGMP (Internet Group Membership Protocol) is a protocol used by IP hosts
to report their multicast group memberships to any immediately neighboring
multicast routers.
Enable WAN Service checkbox: Tick this item to enable the ATM service. Untick
it to stop the ATM service.
Service Name: This is user-defined.
Enable NAT checkbox: If the LAN is configured with a private IP address, the user
should select this checkbox. The NAT submenu on the left side main panel will be
displayed after reboot. The user can then configure NAT-related features after the
system comes up. If a private IP address is not used on the LAN side, this checkbox
should be de-selected to free up system resources for better performance. When
the system comes back after reboot, the NAT submenu will not be displayed on the
left main panel. The default setting for PPPoE/PPPoA is disabled.
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