Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 233)

Chapter 4 - Configuring Network Modems 4-15
MN/22156, rev 12 Network
This dialog is used to configure the IP Addressing and Link Configuration
settings for the Ethernet communication ports that are on the rear panel of the
Series800 units. These ports consist of the following interfaces:
• GE (10/100/1000 BaseT Gigabit Ethernet) interface(s).
This interface serves as the Customer Traffic port.
There is one GE port on the CDM-840 and the CDD-880, and two GE
ports (GE1 and GE2) on the CDM-800.
• FE (10/100 BaseT Fast Ethernet) interface.
This interface serves as the Management (M&C) port for the VMS.
The figure above represents the dialog for a CDM-800. In this example, the
interfaces appear in the order GE1, GE2, FE.
To modify the interface settings, select a table listing and click on the Modify
button.
Set the IP Address and Subnet Mask (valid range is 8-30).
Note that if the GE address/mask is set incorrectly, a traffic Ethernet alarm
will be generated in the VMS.
Using the pull-down menu, select the desired Link Configuration setting
for line speed and duplex. Note that the recommended setting is Auto.
Network | Routes
Because satellite networks are often used as extensions for access to services
such as the Internet or the PSTN, they lend themselves quite readily to private
addressing. For example, to provide Internet access to the satellite network, only
the Hub requires a public IP address in order for the entire satellite network that
is controlled by the Hub to have access to the Internet backbone. Utilizing
Network Address Translation (NAT), the administrator can effectively address
the network using a minimum number of static route statements.
Example:
The IP address 172.16.0.0 is the private address network number for class B
networks. If there is a router at the Hub with a connection to the Internet, the
operator can define the local network as a class B. If the operator splits the
Class B in half and points the upper half toward the satellite there will be
over 16,000 usable addresses at the Hub as well as at the Remotes.
By putting the one route statement “Remotes 172.16.128.0/17 WAN to
LAN” in the Hub modem, and by using the route statement “GW 0.0.0.0/0
LAN to WAN” at each of the Remote modems, the network will
successfully route packets. The Remotes can then be subnetted as class C
networks or below. Additional routers at the Remotes can be added for