User's Manual

EnRoute500 User’s Guide

TR0149 Rev. C5

node) must also have addresses that belong to this address space in order to facilitate DHCP

relay and selection of client addresses from the correct DHCP scope on servers that serve

hosts connected to different subnets. The client interface addresses need to be configured

statically. It is recommended that a contiguous range of addresses at the lower end of the

address space be set aside, one for each client interface on the mesh nodes.

Consider the example where a mesh cluster consists of 3 nodes, including the gateway node.

The DHCP server resides on a host that also acts as the upstream router and is connected to

the mesh gateway’s wired segment. We will set aside 15 addresses for the mesh nodes’ client

interfaces (3 nodes, up to 5 interfaces per node). Assuming the client address space is

192.168.5.0/24, with available addresses from 192.168.5.1 to 192.168.5.255, we will use

192.168.5.1 for the server hosting the DHCP server, 192.168.5.2 for the mesh gateway’s

backhaul interface, set aside 192.168.5.3 to 192.168.5.18 for the mesh AP interfaces, and

configure the remote DHCP server to serve addresses in the range of 192.168.5.19 to

192.168.5.254 to wireless clients. We will keep 192.168.5.255 as the broadcast address for

the mesh cluster.

10.2.1 Configuring the EnRoute500s

Each EnRoute500 in a mesh cluster must be configured to use the same centralized DHCP

server. This is set using the ‘dhcp.relay.enable’ parameter in the ‘sys’ interface as shown in the

example below.

> use sys

sys> set dhcp.relay.enable=yes

DHCP relay mode can be enabled via the web interface on the “DHCP Relay” sub-tab under

the “DHCP” tab on the “System Parameters” page (see Figure 37).

Each client interface on the EnRoute500 must be configured to be in server mode for it to

support relay of addresses to clients from a central DHCP server. This configuration is set with

the ‘dhcp.role’ parameter in each of the client interfaces (eth0,wlan1-4). The example below

shows how to set this parameter for the wlan1 and wlan2 interfaces.

> use wlan1

wlan1> set dhcp=server

> use wlan2

wlan2> set dhcp=server

It is possible to disable DHCP address assignments to clients on a per-client interface basis

and have them use static addresses instead. To disable DHCP for an interface, set the

‘dhcp.role’ parameter in the interface to ‘none’, as shown below

> use wlan3

wlan3> set dhcp=none