708, 709FX, 710FX2, 711FX3, 712FX4, 714FX6, 716, 7010TX, 7012FX2, 7018, & 7506GX2 Series
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.
Configuring DHCP Server and Relay Agent
The following information will be helpful as you configure the N-Tron DHCP Server. A high level flow of the basic configuration is provided by Figure: Flow_DHCP_1.
In order to use the DHCP server in offering IP addresses, several configuration steps are essential. N-Tron uses Profiles and Mappings to organize how the IP’s will be offered to Clients. You must have at least one Profile defined in order to add mappings.
The menu Setup Profiles shows DEFAULT as a Profile. The DEFAULT Profile allows you to define some changeable parameters that are automatically included within the Profile you define. The changeable Profile entries can be seen by pressing the, Advanced, button when adding a Profile. You do not have to make use of this DEFAULT Profile. The DEFAULT Profile information is used by the DHCP Server when communicating with the DHCP Client. The use of the DEFAULT Profile simplifies the changing of information of already defined Profiles by automatically inserting data found in the DEFAULT profile into the Profile used when allocating an IP addresses to a Client.
The Profile Setup has entries to define an Address Pool range. It is important to decide what this range should be, since your IP address mappings will be a subset of this range. Profiles cannot overlap their Address Pool ranges with other Profiles.
The Profile Setup Lease Time: designates the amount of time an IP will be honored by a Server that has made an offer to a Client. The Lease Time insures that the IP address offered by the Server will not be offered to any other Client device until the Lease expires. The Client will use a renewal process to maintain the IP for longer periods of time by requesting an extension for the address from the server.
Saving DHCP Settings and Data: The DHCP Profiles, Mappings and Bindings are stored in the N-Tron switch file system when you click on the screen Update button. These changes are automatically saved for you. Parameters such as Enabling and Disabling the DHCP Server are part of the switch Settings configuration and you will be prompted by a message to save your changes.
Examples
Examples are provided for the following settings:
Setting up a Dynamic Range
Setting up a Static Range
Setting up a Single IP
Setting up an N-Tron Switch as a Client Device
Setting up the Relay Agent to obtain a Local IP Address
Setting up a redundant DHCP Server using 2 N-Rings across N-Link
N-Tron DHCP Setup Process –Basic Setup Flow
Getting connected with N-Tron DHCP Server
N-Tron Switches provide a Web Interface for all your DHCP configurations.
The two main menus for DHCP configuration are:
DHCP – contains the configuration for both the DHCP Server and Relay Agent.
Administration – clicking on Administration / System / IP Configuration menu, allows you to configure the DHCP Client to be either Static or DHCP. In order to receive an IP address from a DHCP Server the switch must be configured for DHCP.
DHCP Menu
Enabling the DHCP Server
Setting up the DHCP Server Profiles
Setting up the DHCP Server Mappings
N-Tron provides the following Mapping Types:
Setting up a 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.
Topology:
Example:
In this example connections can be made to any port on the server or on a switch connected to the server. The IP address given will be the next available address in the range defined.
Setup:
Click on: DHCP / Server / Setup IP Maps. See Figure: Menu_1
Click on: Dynamic Range. See Figure: Mapping_1
Reference Figure: Dynamic_1 below.
Select the Profile you wish to add this mapping too.
Enter Low IP: Ex. 192.168.2.25
Enter High IP: Ex. 192.168.2.35
Click Update when finished.
Mapping:
Connection:
Connect the Ethernet cable to the device and to a port on the Server.
Powering On and Status Display:
Setting up a Static Range
Basic configuration using Option 82 Relay Agent
The first step is to setup the Relay Agent. See Setup Option 82: DHCP Server Switch.
The second step is to setup the DHCP Server. See Setup Option 82: DHCP Server Switch.
Topology:
Example : A connection is made from the Client to a designated port (TX1) on the Relay Agent.
In this example:
Make configuration on the Relay Agent. See Figure: Option82_1
Configuration on the Server side should match the configuration on the Relay Agent: See Figure: Option82_2
Notes:
Other Data : Circuit ID
There are four formats you can use to enter Circuit ID data: Hex, MAC, IP and String
The default string has particular meaning to an N-Tron Server switch: (Port-VLAN). For example TX1-0001.
Entering string data in any other format will require you to use the Relay Agent Type : Generic when configuring the DHCP Server. See Figure: Option82_2.
N-Tron Relay Agent Setup Process – Basic Setup Flow
Setup Option 82: Relay Agent Switch
N-Tron DHCP Server Static Range Setup Process – Basic Setup Flow
Setup Option 82: DHCP Server Switch
Mapping:
Connection:
Powering On and Status Display:
Setting up a Single IP
Basic configuration using Option 61 or MAC Address
Topology:
Example:
Setup:
Mapping:
Connection:
Powering On and Status Display:
Setting up an N-Tron Switch as a Client Device
Topology:
Example:
Setup:
Relay Agent -Stand Alone
Setting up the Relay Agent to obtain a Local IP Address
Topology:
Example:
Setup:
Connection:
Powering On and Display:
Advanced DHCP Server Topologies
Setting up a redundant DHCP Server using 2 N-Rings across N-Link
Topology 1:
Topology 2:
Example:
Setup:
First Step: Configure N-Link to redundantly couple 2 N-Ring networks
Reference Figure: Advanced_Redundancy_T1 and the User Manual & Installation Guide for the switch.
Ensure the Coupler and Control cables are disconnected at this point.
Get Both N-Rings working with Status OK.
Configure N-Link Slave: Ensure that the N-Link Slave is set to Auto Configure. Save Configuration.
Configure N-Link Master: Select the Control and Coupler ports. Save the Configuration.
Connect the Control Link cable.
Connect the Coupler Link cables.
Check N-Link status by selecting the N-Link Status View page.
NOTE: There must be an N-Link aware switch on either side of the Master.
NOTE: There must be a direct link between the Master and Slave Control ports and between the Master and Slave Partner ports. Use of media converters or other switches in these locations is not supported.
Second Step: Configure the DHCP Servers for Redundancy
The Servers will be configured identically with Option61 Static Mappings.
Warning: If a Dynamic Range is created, it can only reside on one switch.
Only one DHCP Server will be configured. The other DHCP Server will receive the DHCP configuration by Uploading from the configured DHCP Server.
Reference the Basic DHCP setup information above and Figure: Advanced_Redundancy_T1
Configuring one of the DHCP Servers (1)
Enable the DHCP Server, Add a Profile. See: Enabling the DHCP Server and Setting up the DHCP Server Profiles.
Add an Option61 Static entry for each N-Link switch. See: Setting up a Single IP.
Configuring DHCP Servers (2)
Third Step: Configure the DHCP Relay Agent
Connection:
Powering On and Display:
Firmware/Config–TFTP
The TFTP tab under the Firmware/Config category gives the administrator the ability to upload or download a config file for an N-Tron switch. This allows administrators to backup their configurations to a server offsite in case they need to reload their custom configurations at a later time. It is important not to cycle power on the switch or interrupt the data connection between the TFTP server and the switch while you are uploading/downloading a config file. The switch will not stop working if this does occur, but the administrator will have to retransfer the file. This dialog allows for selection of configuration items to save, and of configurations items to download, if available in the configuration file.
Firmware/Config – TFTP, Continued…
Install and setup the TFTP Server.
The status bar along the bottom of the TFTP Server window shows the TFTP Server root directory and IP address.
The Configuration allows you to enter a directory into which your downloaded file from the switch will be stored. The Upload Configuration on the switch will also access this directory when uploading a new configuration. Security should also be set to both receive and Transmit files.
Notes:
To enable ping in Windows Firewall:
1. Open the Control Panel (from the Start menu. Choose Control Panel; or Settings and then Control Panel).
2. Open Windows Firewall (click Network and Internet Connections then Windows Firewall; or double-click Windows Firewall.
3. Click the Advanced tab.
4. In the ICMP box click the Settings... button.
5. Tick the Allow incoming echo request box.
6. Click on OK and then OK again.
7. Close the Control Panel.
It is the customer's responsibility to review the advice provided herein and its applicability to the system. HMS makes no representation about specific knowledge of the customer's system or the specific performance of the system. HMS is not responsible for any damage to equipment or connected systems. The use of this document is at your own risk. HMS standard product warranty applies.
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