Prisma SD-WAN
Configure a DHCP Relay
Table of Contents
Configure a DHCP Relay
Let us learn to configure a DHCP relay in Prisma SD-WAN. DHCP Relay is a branch-site
feature that is configured at the interface level on a device.
| Where Can I Use This? | What Do I Need? |
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DHCP Relay is a branch-site feature that is configured at the interface level on a device.
Typically, a DHCP Relay agent is used to forward DHCP requests between clients and
servers that are not on the same physical subnet. DHCP Relay can be configured on a
controller port, a LAN port, or on a sub-interface that has a defined, static IP
address. DHCP Relay is enabled for VRF.
When a ION device receives a
DHCP request from a client on the interface configured with DHCP
Relay, it forwards those requests to configured DHCP servers. It
also listens to DHCP responses from all DHCP servers and relays
them to the client. The DHCP Relay requests are forwarded only when
the ION device is assigned to a site and the site is in active mode.
An
ION device with DHCP Relay:
- Forwards DHCP client broadcast requests to the configured DHCP server.
- Forwards DHCP unicast request from another DHCP Relay agent downstream on the LAN-side to the configured DHCP server.
- Forwards DHCP client/DHCP Relay agent broadcast/unicast requests to another DHCP Relay agent.
In the event of a
DHCP server error, the ION device forwards all rejections back to
the client. In the event of a client rejection, the ION device forwards
all rejections from the client back to the DHCP server.
- Select , select the device you want to configure.On the device's interface configuration page, select the to add any interface.In the General section,
- Enter a Name and (Optional) Description, and add Tags for the port channel interface.For Admin Up, select Up or Down.For Interface Type, select Port.In the Network Setting section,
- Select Use this Port Channel Interface for LAN.Toggle Scope as Global or Local.For IPv4 Configuration, select None, DHCP, or Static.
- If the IP address dynamically assigned, select DHCP.
- If the IP address is fixed and specified manually, select Static. If you select Static, specify the IP Address/Mask, Default Gateway, and DNS server(s).
Select Enable IPv6 On This Interface to configure IPv6.In the DHCP Relay section,- Add DHCP Server IPs addresses.Up to 16 DHCP Server IP addresses may be added.Define the Source Interface used to send DHCP requests to the servers.By default, the controller port is used. Make sure that the defined source interface can reach DHCP server IP addresses and vice versa. If the DHCP server is local to the branch the source interface must be the interface from which the DHCP server is accessible.Enable Option 82, if Yes then configure the Circuit ID, Remote ID, and Reforwarding Policy.The ION device DHCP Relay agent can include additional information by using DHCP Option 82, Circuit ID, and Remote ID, which the DHCP server uses to allocate the appropriate IP address.
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