Revision 2010-11-15
Page 3 of 33
Overview
The Dynamic Host Configuration Protocol (DHCP) provides configuration parameters to Internet hosts.
DHCP consists of two components: a protocol for delivering host-specific configuration parameters from a
DHCP server to a host and a mechanism for allocation of network addresses to hosts. DHCP is built on a
client-server model, where designated DHCP server hosts allocate network addresses and deliver
configuration parameters to dynamically configured hosts.
(DHCP is explained in RFC 2131).
The N-Tron DHCP Switch can be configured to be a DHCP Server, a DHCP Relay Agent, or both.
DHCP Server
- manages and allocates IP address from a pool of address, defined by Profiles, to
requesting Clients.
Relay Agent
– receives DHCP requests messages and directs them to a specific DHCP server.
Before sending the DHCP request, the Relay Agent appends identifying information into the
message (Circuit ID + Remote ID).
o
Circuit ID
– contains information that identifies the port location that the DHCP request
comes from. For example (TX1-0001) defines request came from Port 1 – VLAN 1.
o
Remote ID
– contains information that identifies the Relay Agent device. (For example: the
IP address or MAC address of the Relay Agent.)
It can also Assign a Local IP address when a client is connected to a specific port. Relay Agent is
explained in RFC 3046.
The N-Tron DHCP Server supports several methods of allocating IP address in a managed manner.
Dynamic Range
– IP address allocation is Dynamic and is based on the first free IP address in the
defined range. The IP address could be different each time the Client makes a request.
Static Range
: Option 82 Relay Agent- IP address allocation is Static and is based on matching
Option 82 information received from a Relay Agent. The same IP address will be given each time to
a specific Client.
Single IP
: Option 61 or MAC - IP address allocation is Static and is based on matching Option 61
information received from a Client. The same IP address will be given each time to a specific
Client.
