DHCP (Dynamic Host Configuration Protocol) is a method to assign IP addresses automatically to network clients. You can configure your XTM device as a DHCP server for the networks that it protects. If you have a DHCP server, we recommend that you continue to use that server for DHCP.
These DHCP settings apply to trusted and optional interfaces, and to VLAN, Bridge, and Link Aggregation interfaces in the trusted and optional security zones.
If your XTM device is configured in drop-in mode, see Configure DHCP in Drop-In Mode.
To modify or delete an address pool range:
To reserve a specific IP address for a client:
To modify or delete a reservation:
DHCP options, also known as vendor extensions, enable you to specify DHCP configuration parameters and other control information, as described in RFC 2132. You can add predefined or custom DHCP options. Custom options are supported in Fireware XTM v11.9.3 and higher.
The predefined DHCP options are:
|DHCP Option Code||Name||Type||Description|
|150||TFTP Server IP||IP address(es)||
The IP address of the TFTP server where the DHCP client can download the boot configuration.
|66||TFTP Server Name||Text||The name of the TFTP server where the DHCP client can download the boot configuration.|
|67||TFTP Boot Filename||Text||The name of the boot file.|
|2||Time Offset||4 byte integer||
Time offset in seconds from Coordinated Universal Time (UTC).
|43||Vendor specific information||Text||This option is used by clients and servers to exchange vendor- specific information.|
|120||SIP Servers||IP address(es)||
IPv4 addresses of one or more Session Initiation Protocol (SIP) outbound proxy servers. This option is described in RFC 3361.
|138||CAPWAP Access Controller||IP address(es)||
IPv4 addresses of one or more CAPWAP Access controllers. This option is described in RFC 5417.
|156||DHCP State||1 byte integer (Unsigned)||State of the IP address. This option is used by ShoreTel phones for an FTP boot option.|
Some version of Fireware XTM OS do not support all the predefined options. The Fireware XTM Web UI shows you only the supported options.
In Fireware XTM v11.9.3 and higher, you can add predefined or custom DHCP options.
To add a predefined DHCP option:
If the option required by your vendor is not in the list of predefined options, you can add it as a custom option.
DHCP options 1, 3, and 28 are not supported.
To add a custom DHCP option:
If you use the same DHCP option code for more than one interface, the Type must be the same on each interface.
Fireware XTM versions lower than v11.9.3 support a limited set of predefined DHCP options, and do not support custom options.
To configure DHCP options in an older version of Fireware XTM OS:
By default, when it is configured as a DHCP server your XTM device gives out the DNS and WINS server information configured on the Network Configuration > WINS/DNS tab. To specify different information for your device to assign when it gives out IP addresses, you can add a DNS server for the interface.
Configure DHCP Relay
Add WINS and DNS Server Addresses
Configure an IPv6 DHCP Server