DHCP Relay Policy

Location in GUI: Tenants » XXX » Policies » Protocol » DHCP » Relay Policies

Diagram

Classes

policies (apic.tenants)

Name	Type	Constraint	Mandatory	Default Value
dhcp_relay_policies	List	`[dhcp_relay_policies]`	No

dhcp_relay_policies (apic.tenants.policies)

Name	Type	Constraint	Mandatory
name	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	Yes
description	String	Regex: `^[a-zA-Z0-9\\!#$%()*,-./:;@ _{\|}~?&+]{1,128}$`	No
providers	List	`[providers]`	No

providers (apic.tenants.policies.dhcp_relay_policies)

Name	Type	Constraint	Mandatory
ip	IP		Yes
type	Choice	`epg`, `external_epg`	Yes
tenant	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	No
application_profile	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	No
endpoint_group	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	No
l3out	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	No
external_endpoint_group	String	Regex: `^[a-zA-Z0-9_.:-]{1,64}$`	No

Examples

Example-1: This data model defines a DHCP Relay Policy named DHCP-SERVERS, which enables communication between DHCP clients and servers residing in different subnets or endpoint groups (EPGs). The DHCP servers are specified in the providers section, including details such as the server IP address 6.6.6.6 and its location within the tenant ABC, application profile AP1, and EPG EPG1. The server can be located in either an EPG or an External EPG (L3Out). DHCP Relay Policies are associated with a Bridge Domain alongside a DHCP Option Policy. Key points about DHCP Relay Policies in Cisco ACI:

The fabric inserts DHCP Option 82 (DHCP Relay Agent Information Option) into the DHCP requests it proxies. DHCP servers must support Option 82; otherwise, DHCP offers without this option are dropped by the fabric.
A contract must be created between the DHCP server EPG and the client EPG to allow DHCP communication.
DHCP Relay Policies support both IPv4 and IPv6, including DHCPv6 relay with Option 79 for carrying client link-layer addresses.
Changes to DHCP Relay Policies require redeployment of the associated bridge domain to update the fabric.
DHCP Relay Policies are supported in user or common tenants but not in infra or mgmt tenants.

apic:
  tenants:
    - name: ABC
      policies:
        dhcp_relay_policies:
          - name: DHCP-SERVERS
            description: "My Description"
            providers:
              - ip: 6.6.6.6
                type: epg
                tenant: ABC
                application_profile: AP1
                endpoint_group: EPG1