Digi TransPort WR31 User Manual page 152

Configure network interfaces
IP address
When a private IP host sends a UDP or TCP packet to an Internet IP address, the router will
change the source address of the packet from the private host IP to the router's public IP
address before forwarding the packet onto the Internet host. Additionally it will create an entry
in a NAT table containing the private IP source address, the private IP port number, the public IP
destination address and the destination port number. Conversely, when the router receives a
reply packet back from the public host, it checks the source IP, source port number and
destination port number in the NAT table to determine which private host to forward the packet
to. Before it forwards the packet back to the private host, it changes the destination IP address
of the packet from its public IP address to the IP address of the private host.
IP address and Port
This mode behaves like NAT, but in addition to changing the source IP of the packet from the
private host, it can also change the source port number. This is required if more than one private
host attempts to connect using the same local port number to the same Internet host on the
same remote port number. If such a scenario were to occur with NAT the router would be unable
to determine which private host to route the returning packets to and the connection would fail.
Enable IPsec on this interface
Enables or disables IPSec security features for this Ethernet interface.
Use interface x,y for the source IP address of IPsec packets
By default, the source IP address for an IPsec Eroute is the IP address of the interface on which
IPSec was enabled. By setting this parameter to either PPP or Ethernet and the relevant
interface number, the source address IPSec uses matches that of the Ethernet or PPP interface
specified.
Enable the firewall on this interface
Turns Firewall script processing On or Off for this interface.
Enable DNS inbound blocking
Enables or disables blocking DNS requests on the Ethernet interface, to prevent the interface
from responding to DNS requests over this interface.
Enable DMNR advertisement from this subnet
Enables or disables the subnet defined on the Ethernet interface to be advertised on any defined
Dynamic Mobile Network Routing (DMNR) tunnel. DMNR is available on Verizon Wireless Private
Networks. DMNR provides direct access to devices on the Local Area Network (LAN) at your
company's sites by dynamically advertising locally IP subnets attached to the Digi TransPort's
Ethernet interface(s). Contact Verizon Wireless for more details on DMNR and whether your
network uses DMNR or is eligible for DMNR. For more information on configuring DMNR, see the
Digi document Application Note 53: Configure a Digi TransPort Router to use DMNR (Dynamic
Mobile Network Routing), available on www.digi.com.
Digi TransPort WR Routers User Guide
Configure Ethernet interfaces
152