Installation Guide

Table Of Contents
Task 2: Configuring IP and Ethernet interfaces
NAT, DHCP Server, DHCP Client and DMZ in SM
The system provides NAT (Network Address Translation) for SMs in the following
combinations of NAT and DHCP (Dynamic Host Configuration Protocol):
NAT Disabled
NAT with DHCP Client (DHCP selected as the Connection Type of the WAN interface)
and DHCP Server
NAT with DHCP Client(DHCP selected as the Connection Type of the WAN interface)
NAT with DHCP Server
NAT without DHCP
NAT
NAT isolates devices connected to the Ethernet or wired side of a SM from being
seen directly from the wireless side of the SM. With NAT enabled, the SM has an IP
address for transport traffic (separate from its address for management), terminates
transport traffic and allows you to assign a range of IP addresses to devices that are
connected to the Ethernet or wired side of the SM.
In the Cambium system, NAT supports many protocols, including HTTP, ICMP
(Internet Control Message Protocols), and FTP (File Transfer Protocol). For virtual
private network (VPN) implementation, L2TP over IPSec (Level 2 Tunneling Protocol
over IP Security) and PPTP (Point to Point Tunneling Protocol) are supported.
When NAT is enabled, a reduction in throughput is introduced in the system (due
to processing overhead).
DHCP
DHCP enables a device to be assigned a new IP address and TCP/IP parameters,
including a default gateway, whenever the device reboots. Thus DHCP reduces
configuration time, conserves IP addresses, and allows modules to be moved to a
different network within the Cambium system.
In conjunction with the NAT features, each SM provides the following:
A DHCP server that assigns IP addresses to computers connected to the SM by
Ethernet protocol.
A DHCP client that receives an IP address for the SM from a network DHCP server.
DMZ
In conjunction with the NAT features, a DMZ (Demilitarized Zone) allows the
allotment of one IP address behind the SM for a device to logically exist outside the
firewall and receive network traffic. The first three octets of this IP address must be
identical to the first three octets of the NAT private IP address.
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pmp-0957 (April 2015)