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DHCP

DHCP server is used to automatically assign IP addresses to network devices on the LAN.

SafeUTM interface allows you to configure a range of IP addresses for automatic assignment, as well as to form static bindings of IP addresses to MAC addresses of these devices. Network devices on the local network must be configured to automatically receive network details from DHCP server. Thus, clients send a broadcast request to a LAN segment, and the server intercepts and sends responses to these requests containing the necessary settings for the client.

A static IP address must be configured on the local SafeUTM interface participating in the distribution of addresses.

Configuring Server

In order to configure DHCP for the local interface, you need to go to Services -> DHCP server and click Add.

As a rule, SafeUTM server is the gateway and DNS server for all LAN network devices, so in most cases the service configuration is limited to determining the range of IP addresses. If necessary, you can specify DNS servers, static routes, and WINS server addresses. The list of DHCP server parameters can be seen in the table below:

*If DNS interception is configured on SafeUTM, then name resolution will be performed using the server specified in the DNS interception settings.

If you set the checkbox in the Issue IP addresses specified in authorizations via IP without MAC checkbox, then IP addresses (with the exception of the rule with IP+MAC) used as a user authorization factor (Authorization section) will be issued by the DHCP server.

An example of configuring a DHCP server is shown in the screenshot below:


image-1661607463176.png1. DHCP.png

If no value is specified in the DNS-1 or DNS-2 field, then the DNS server will be SafeUTM for all network devices on the local network.

You can enable/disable, edit or delete rules for issuing IP addresses using control buttons in the Management column.

Also, when using a DHCP server, do not forget to move the slider at the top of the screen near the inscription DHCP server to the Enabled position.


image-1661607506352.png2. DHCP.png

Configuring DHCP server with IP Binding to MAC

To configure the binding of IP address to MAC address in DHCP server, follow these steps:

1. In section Services -> DHCP select tab Binding IP to MAC.
3. DHCP.png

image-1661607531797.png

2. Create an IP-to-MAC binding rule:


image-1661607567505.png4. DHCP.png

An example of the created binding rule is shown in the screenshot below:


image-1661607575294.png5. DHCP.png

To check the created rule, on the computer with the MAC address specified in the rule, get an IP address via DHCP and check the result using command ipconfig /all

image-1661607584669.png

Tips for configuring clients
Some devices provide a MAC address with hyphenated octets ( 01-02-03-04-05-06 ). In the SafeUTM settings, MAC address octets are separated only by colons ( 01:02:03:04:05:06 ). Therefore, be careful when coordinating the settings of client devices and DHCP server on SafeUTM.