Routing Configuration; Routing Mode - D-Link DSR-250N User Manual

Unified Services Router
Delete: Deletes the selected IP Aliases.
3.5

Routing Configuration

Routing between the LAN and WAN will impact the way this router handles traffic that is received on
any of its physical interfaces. The routing mode of the gateway is core to the behavior of the traffic
flow between the secure LAN and the internet.

3.5.1 Routing Mode

Setup > Internet Settings > Routing Mode
This device supports classical routing, network address translation (NAT), and transport mode
routing.
•
With classical routing, devices on the LAN can be directly accessed from the internet by their
public IP addresses (assuming appropriate firewall settings). If your ISP has assigned an IP
address for each of the computers that you use, select Classic Routing.
•
NAT is a technique which allows several computers on a LAN to share an Internet connection.
The computers on the LAN use a "private" IP address range while the WAN port on the router
is configured with a single "public" IP address. Along with connection sharing, NAT also hides
internal IP addresses from the computers on the Internet. NAT is required if your ISP has
assigned only one IP address to you. The computers that connect through the router will need to
be assigned IP addresses from a private subnet.
•
When Transparent Routing Mode is enabled, NAT is not performed on traffic between LAN and
WAN. Broadcast and multicast packets that arrive on the LAN interface are switched to the
WAN and vice versa, if they do not get filtered by firewall or VPN policies. To maintain the
LAN and WAN in the same broadcast domain select Transparent mode, which allows bridging
of traffic from LAN to WAN and vice versa, except for router-terminated traffic and other
management traffic.
transparent mode assuming the LAN and WAN are configured to be in the same broadcast
domain.

NAT routing has a feature called "NAT Hair-pinning" that allows internal network users on the LAN
and DMZ to access internal servers (e.g. an internal FTP server) using their externally-known domain
name. This is also referred to as "NAT loopback" since LAN generated traffic is redirected through the
firewall to reach LAN servers by their external name.
•
When Bridge Mode routing is enabled, the physical LAN port and secondary WAN/DMZ (port
2) interfaces are bridged together at Layer 2, creating an aggregate network. The other LAN
ports and the primary WAN (WAN1) are not part of this bridge, and the router asks as a NAT
All DSR features (such as 3G modem support) are supported in
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