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Related Topics
Configure an IPv4 DHCP Server
DHCP (Dynamic Host Configuration Protocol) is a method to assign IP addresses automatically to network clients. You can configure your Firebox 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, optional, or custom interfaces, and to VLAN, Bridge, and Link Aggregation interfaces in trusted, optional, or custom security zones.
If you Firebox is configured in drop-in mode, the configuration steps are different. To configure DHCP in drop-in mode, see Configure DHCP in Drop-In Mode.
The features available in WatchGuard System Manager (WSM) can be different for different versions of Fireware. If your Firebox does not run Fireware OS v11.10.x or higher, the content in this Help topic might not apply to your Firebox.
For instructions to complete the procedures in this topic for a Firebox that runs an older version of Fireware, see:
Configure IPv4 DHCP in Mixed Routing Mode in WatchGuard System Manager v11.9.4 Help
Configure DHCP for IPv4
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- Select Network > Interfaces.
- Select a trusted, optional, or custom interface. Click Edit.
- From the drop-down list, select DHCP Server.
- To add a group of IP addresses to assign to users on this interface, in the Address Pool section, click Add.
- Specify starting and ending IP addresses on the same subnet, then click OK.
The address pool must belong either to the interface’s primary or secondary IP subnet.
You can configure a maximum of six address ranges. Address groups are used from first to last. Addresses in each group are assigned by number, from lowest to highest. - To change the default lease time for addresses in the DHCP address pool, select a different option in the Lease Time drop-down list.
This is the time interval that a DHCP client can use an IP address that it receives from the DHCP server. When the lease time is about to expire, the client sends data to the DHCP server to get a new lease.
To modify or delete an address pool range:
- In the Address Pool table select the entry.
- Click Edit to edit the selected range.
- Click Remove to remove the selected range.
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- Select Network > Configuration.
- Select a trusted, optional, or custom interface. Click Configure.
To configure DHCP for a wireless guest network, select Network > Wireless and click Configure for the wireless guest network. - Select Use DHCP Server.
- To add a group of IP addresses to assign to users on this interface, in the Address Pool section, click Add.
- Specify starting and ending IP addresses on the same subnet, then click OK.
The address pool must belong either to the interface’s primary or secondary IP subnet.
You can configure a maximum of six address ranges. Address groups are used from first to last. Addresses in each group are assigned by number, from lowest to highest. - To change the default lease time for addresses in the DHCP address pool, select a different option in the Leasing Time drop-down list.
This is the time interval that a DHCP client can use an IP address that it receives from the DHCP server. When the lease time is about to expire, the client sends data to the DHCP server to get a new lease.
To modify or delete an address pool range:
- In the Address Pool table select the entry.
- Click Edit to edit the selected range.
- Click Remove to remove the selected range.
Configure DHCP Reservations
You can use DHCP reservations to reserve a specific IP address for a client.
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To reserve a specific IP address for a client:
- In the Reserved Addresses section, type a name for the reservation, the IP address you want to reserve, and the MAC address of the client’s network card.
The DHCP reservation name cannot start or end with a dot (.) or dash (-), and cannot contain an underscore (_).
- Click Add.
To modify or delete a reservation:
- In the Reserved Addresses table, select the reservation.
- Click Edit to edit the selected reservation.
- Click Remove to remove the selected reservation.
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To reserve a specific IP address for a client:
- In the Reserved Addresses section, click Add.
For a wireless guest network, click DHCP Reservations and then click Add. - Type a name for the reservation, the IP address you want to reserve, and the MAC address of the client’s network card.
The DHCP reservation name cannot start or end with a dot (.) or dash (-), and cannot contain an underscore (_). - Click OK.
To modify or delete a reservation:
- In the Reserved Addresses table, select the reservation.
- Click Edit to edit the selected reservation.
- Click Remove to remove the selected reservation.
Configure DHCP Options
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 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 versions of Fireware OS do not support all the predefined options. If the option code you select requires a specific minimum version of Fireware, a notation appears to the right of the selected code in Policy Manager.
You can add a predefined DHCP option or a custom DHCP option. If you use the same DHCP option code for more than one interface, the Type configured for the option code must be the same on each interface.
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- In the DHCP Options list, click Add.
The Add DHCP Option dialog box appears. Predefined Option is selected by default
- From the Code drop-down list, select the DHCP option code.
The Name and Value associated with the code are selected automatically and you cannot edit these. - In the Value text box, type the value to assign to this option. It must match the Type for this option.
- Click OK.
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- Click DHCP Options.
- Click Add.
The Add DHCP Option dialog box appears. Predefined Option is selected by default
- From the Code drop-down list, select the DHCP option code.
The Name and Value associated with the code are selected automatically and you cannot edit these. - In the Value text box, type the value to assign to this option. It must match the Type for this option.
- Click OK.
If the option required by your vendor is not in the list of predefined options, you can add it as a custom option.
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- In the DHCP Options list, click Add.
The Add DHCP Option dialog box appears.
- Select Custom Option.
- In the Code text box, type the DHCP option code.
- In the Name text box, type a name to describe this DHCP option.
- From the Type drop-down list, select the type of value required by this option.
- In the Value text box, type the value to assign to this option. It must match the Type you selected.
- Click OK.
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- Click Add.
The Add DHCP Option dialog box appears. - Select Custom Option.
- In the Code text box, type the DHCP option code.
- In the Name text box, type a name to describe this DHCP option.
- From the Type drop-down list, select the type of value required for this option.
- In the Value text box, type or select the value to assign to this option. It must match the Type you selected.
- Click OK.
DHCP option codes 1, 3, and 28 are not supported.
Configure Per-Interface WINS/DNS
By default, when it is configured as a DHCP server your Firebox 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.
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In the DHCP Server tab, select the DNS/WINS tab.
- To change the default DNS domain, in the Domain Name text box type a domain name.
- To create a new DNS server entry, in the DNS Server text box, type an IP address, and click Add.
- To create a new WINS server entry, in the WINS Server text box, type an IP address and click Add.
- To remove the selected server from a list, click Remove.
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In the IPv4 tab for an interface, click Configure DNS/WINS servers.
- To change the default DNS domain, type a Domain Name.
- To create a new DNS or WINS server entry, click Add adjacent to the server type you want, type an IP address, and click OK.
- To change the IP address of the selected server, click Edit.
- To remove the selected server from the adjacent list, click Delete.
- To configure the per-interface DNS/WINS settings, click DNS/WINS, below the Use DHCP Server drop-down list.
See Also
Add WINS and DNS Server Addresses