Configure an Interface as a DHCP Client

Before configuring a firewall interface as a DHCP client, make sure you have configured a Layer 3 Ethernet or Layer 3 VLAN interface, and the interface is assigned to a virtual router and a zone. Perform this task if you need to use DHCP to request an IPv4 address for an interface on your firewall.
  1. Configure an interface as a DHCP client.
    1. Select
      Network
      Interfaces
      .
    2. On the
      Ethernet
      tab or the
      VLAN
      tab,
      Add
      an interface, or select a configured interface, that you want to be a DHCP client.
    3. Select the
      IPv4
      tab; for
      Type
      , select
      DHCP Client
      .
    4. Select
      Enable
      .
    5. (
      Optional
      ) Select
      Automatically create default route pointing to default gateway provided by server
      . This setting is enabled by default. It causes the firewall to create a static route to the default gateway, which is useful when clients are trying to access many destinations that do not need to have routes maintained in a routing table on the firewall.
    6. (
      Optional
      ) Enter a
      Default Route Metric
      (priority level) for the route between the firewall and the DHCP server (range is 1 to 65,535; default is 10). A route with a lower number has higher priority during route selection. For example, a route with a metric of 10 is used before a route with a metric of 100.
      The
      Default Route Metric
      for the route between the firewall and the DHCP server is 10 by default. If the static default route 0.0.0.0/0 uses the DHCP interface as its egress interface, that route’s default
      Metric
      is also 10. Therefore, there are two routes with a metric of 10 and the firewall can randomly choose one of the routes one time and the other route another time.
      Suppose you select
      Automatically create default route pointing to default gateway provided by server
      and you select a virtual router, and add a static route for a Layer 3 interface and you change the
      Metric
      (which defaults to 10) to a value greater than 10 (let’s say 100). You Commit. In the route table, the route’s metric does not indicate 100; it indicates the default of 10 as expected because 10 takes precedence over the configured value of 100. But if you change the static route’s
      Metric
      to a value less than 10 (let’s say 6), the route in the route table is updated to indicate the configured metric of 6.
    7. (
      Optional
      ) Select
      Show DHCP Client Runtime Info
      to see all of the settings the client has inherited from its DHCP server.
  2. Commit your changes.
    Click
    OK
    and
    Commit
    .
    Now the Ethernet interface indicates
    Dynamic-DHCP Client
    in its
    IP Address
    field on the
    Ethernet
    tab.
  3. (
    Optional
    ) See which interfaces on the firewall are configured as DHCP clients.
    1. Select
      Network
      Interfaces
      Ethernet
      and look in the
      IP Address
      field to see which interfaces indicate DHCP Client.
    2. Select
      Network
      Interfaces
      VLAN
      and look in the
      IP Address
      field to see which interfaces indicate DHCP Client.

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