Jump to:navigation, search
Wiki





























De.png
En.png
Fr.png






Setting up the DHCP server for an IPv4 network
Last adaptation to the version: 12.6.0
New:
  • Updated to Redesign of the webinterface
notempty
This article refers to a Resellerpreview

12.5 12.4 11.8.4 11.7

Access: UTM-IP:Port or UTM-URL:Port
Port as configured at Network / Appliance Settings / Webserver
Default-Port: 11115
i.e.: https://utm.ttt-point.de:11115
Default: https://192.168.175.1:11115
Network Network configuration



Prepare IP address ranges

Network configuration UTMuser@firewall.name.fqdnNetwork UTM v12.6 DHCP Server IPv4 Netzwerkkonfiguration-en.pngNetzwerkschnittstellen

In order for the firewall to function as a DHCP server in a network, a fixed IP from the network area to be assigned must be located on the corresponding interface. In the example, IP addresses are assigned in the network 192.0.2.0/24. To realise this, an IP from this network is added to the interface. LAN3 IP addresses → If necessary, enter an IP from the desired network with the desired subnet mask in the click box. Here 192.168.222.1/24



Set up DHCP server

Network configuration UTMuser@firewall.name.fqdnNetwork UTM v12.6 DHCP Server IPv4 DHCP-Pools-en.pngDHCP Pools

Under Network Network Configuration  Area DHCP Pools multiple DHCP pools can be added.

After clicking Add Pool, the setup wizard opens and the DHCP parameters can be specified.


Pool hinzufügen UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Pool erstellen Schritt 1-en.png
Step 1: Name and IP range
Step 1 requires the Name for the pool and the valid IP range for the DHCP.
In the example, the following IP addresses are assigned
Pool start address: 192.168.222.150/--- 
Pool end address: 192.168.222.170/--- 
Pool hinzufügen UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Pool erstellen Schritt 2-en.png
Step 2: Nameserver
In step 2, the DNS server for the DHCP clients can be specified.
Either the IP of a public DNS server or the IP of the firewall itself can be entered here. In this example, the clients use the firewall itself as DNS.notempty
In order for the UTM to also answer the DNS queries from the internal network, a corresponding rule is required.
Pool hinzufügen UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Pool erstellen Schritt 3-en.png
Step 3: Router + options
In step 3 of the wizard, the default gateway of the DHCP clients is specified.
Caution: Normally, the IP of the firewall is always entered here.notempty
An incorrect entry in this field may prevent access to the Internet!














Edit pool

After the pool has been created correctly, the pool start and end address can be changed and other parameters of the DHCP pool can be set up to be passed to the DHCP client.

Tab General
General

Pool bearbeiten UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Pool bearbeiten Allgemein-en.pngPool bearbeiten Bereich Allgemein

Changes to the pool range start and pool range end possible



Tab Options
Options - DHCP Option
Option Option number Example parameters Comments Pool bearbeiten UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Pool bearbeiten Einstellungen-en.pngPool bearbeiten Bereich Allgemein
Router: 3 »192.168.222.1 Router configured as in step 3
Domain name: 15 securepoint.local Name of the domain in which the DHCP leases are assigned
Domain name server: 5 »192.168.222.1 Name server as configured in step 2
Netbios name server: 44     NetBIOS over TCP/IP Name Server Option
SMTP-Server: 69     Simple Mail Transport Protocol (SMTP) Server Option
NTP Server: 41     Servers should be listed in order of preference.
Vendor Encapsulated Options: 43     Values must be given coded.
TFTP Server Name: 66 i.e.: profile.gigaset.net The IPv4 address, or the hostname of the TFTP server
option tftp-server-name text;
  
Bootfile Name: 67 The name of the bootfile file
option bootfile-name text;
  
Default URL: 114 https://teamwork.gigaset.com/gigawiki/display/GPPPO/DHCP+option+114 Default URL
option default-url string;
  
VLAN ID: 132     The ID of the VLAN used
option vlan-id code 132 = text;
option vlan-id "128";
  
Next Server:notempty
New as of: v12.5
    The IPv4 address of the Next server
  • If the value is missing, TFTP may not work.
  • Default Lease Time: 51 600 Seconds Default validity period of the IP address if the client has not requested an explicit duration.
    Maximal Lease Time: 7200 Seconds Maximum validity period of the IP address in seconds that the client may receive when explicitly requested.
    Reject unknown clients: No If activated , an IP address is only assigned if there is a entry at Static DHCP tab for the MAC address of the client.
  • A client is also considered as known if there is an entry with an IP address from any other pool
    Example:

    Pool 1: 10.10.10.10 - 10.10.10.20 (Net on LAN3)
    Pool 2: 10.20.20.20 - 10.20.20.30 (Net on LAN4)
    Both pools with option Reject unknown clients
    Static IP 10.10.10.15 (from pool 1) for MAC address 01:23:45:67:89:AB
    Client with MAC address 01:23:45:67:89:AB receives at LAN3 always: 10.10.10.15

    Client with MAC address 01:23:45:67:89:AB receives at LAN4 e.g.: 10.20.20.21
      
  • DHCP Setup

    The Setup button opens a dialogue for the DHCP settings.

    Caption Value Description DHCP Setup UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 DHCP-Pools Einstellungen-en.pngDHCP Setup
    Ignore other SDHCP-Servers (IPv4): No If Yes is enabled, other DHCP servers for IPv4 are ignored.
    Ignore other SDHCP-Servers (IPv4): No If Yes is enabled, other DHCP servers for IPv6 are ignored.



    Static DHCP

    If hosts are to be assigned predefined IP addresses ( fixed IPs bound to the MAC address, but assigned by the UTM), these IPs can be reserved with static leases:
    Configuration under Network Network Configuration  Area Static DHCP Button Add Lease

    Host: MaxMustermann-Laptop Meaningful host name Lease hinzufügen UTMuser@firewall.name.fqdnNetworkNetwork configuration UTM v12.6 DHCP Server IPv4 Lease hinzufuegen-en.pngDialogue Add lease
    Ethernet: 12:34:56:78:90:AB MAC address of the host
    IP: 192.168.222.111/---  IP address to be reserved exclusively for this host
    Save and close Speichert und übernimmt den Lease und schließt den Erstellungsdialog.
    notempty
    Important: Leases must necessarily be in an existing DHCP pool!
    Network configuration UTMuser@firewall.name.fqdnNetwork UTM v12.6 DHCP Server IPv4 statisches DHCP-en.pngStatic DHCP
    notempty
    Joint use of static and dynamic IP addresses within a pool is possible.



    Static leases outside a pool

    Existing static leases that are not within a DHCP pool must be changed!

    If such leases are detected after an update, a message is displayed prompting to adjust the DHCP settings.
    It ist now possible that either

    • the leases are adapted and relocated in existing pools
      or
    • additional DHCP pools are created that contain static leases
      or
    • existing DHCP pools are extended so that they include static leases
    UTM v12.6 DHCP Server IPv4 DHCP Warnung-en.png
    Warning at login

    Widget

    In the administrator interface of the UTM, there is a DHCP widget that provides an overview of the existing DHCP connections.
    Further information can be found in the Wiki article UTM Widgets.