DHCP
DHCP provides TCP/IP and link-layer configuration parameters and provides network
addresses to dynamically configured hosts on a TCP/IP network.
| Where Can I Use This? | What Do I Need? |
|---|
- NGFW (Managed by PAN-OS or Panorama)
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This section describes Dynamic Host Configuration Protocol
(DHCP) and the tasks required to configure an interface on a Palo
Alto Networks® firewall to act as a DHCP server, client,
or relay agent. By assigning these roles to different interfaces,
the firewall can perform multiple roles.
DHCP is a standardized protocol defined in
RFC
2131,
Dynamic Host Configuration Protocol. DHCP has two main
purposes: to provide TCP/IP and link-layer configuration parameters and to provide
network addresses to dynamically configured hosts on a TCP/IP network.
DHCP uses a client-server model of communication. This model consists of three roles that
the device can fulfill: DHCP client, DHCP server, and DHCP relay agent.
A device acting as a DHCP client (host) can request an IP address and other
configuration settings from a DHCP server. Users on client devices save
configuration time and effort, and need not know the network’s addressing plan
or other resources and options they are inheriting from the DHCP server.
A device acting as a DHCP server can service clients. By using any of three
DHCP Address Allocation Methods, you save configuration time and have the benefit of reusing
a limited number of IP addresses when a client no longer needs network
connectivity. The server can deliver IP addressing and many DHCP options to many
clients.
A device acting as a DHCP relay agent transmits DHCP messages between DHCP
clients and servers.
DHCP uses
User Datagram Protocol (UDP),
RFC
768, as its transport protocol. DHCP messages that a client sends to a server
are sent to well-known port 67 (UDP—Bootstrap Protocol and DHCP).
DHCP Messages that a server sends to a client are sent to port
68.
An interface on a Palo Alto Networks
® firewall can perform the role of a DHCP
server, client, or relay agent. The interface of a DHCP server or relay agent must be a
Layer 3 Ethernet, Aggregated Ethernet, or Layer 3 VLAN interface. You configure the
firewall interfaces with the appropriate settings for any combination of roles. The
behavior of each role is summarized in
Firewall as a DHCP Server and Client.
The firewall can also function as a
DHCPv6 client, with or without
prefix delegation.
The firewall supports DHCPv4 Server and DHCPv6 Relay.
The Palo Alto Networks implementation of DHCP server supports IPv4 addresses only. Its
DHCP relay implementation supports IPv4 and IPv6. DHCP client supports IPv4 and IPv6
addresses. DHCP client is not supported in High Availability active/active mode.
