Enabling External DHCP on Omada

This document shows a method of allowing the use of DHCP servers (such as Windows or Linux) that are on your network to service DHCP for network attached devices. This is an alternative to using the built in DHCP from Omada.

Assumptions

  1. Multiple VLANs
  2. Multiple Omada Switches
  3. Omada Router
  4. Omada AP (not talked about in this)
  5. Omada Controller, Software or Hardware based
  6. Omada 5.13.24
  7. All Omada hardware will have its management IP on VLAN 1
  8. DHCP and DNS set up on servers.  In this case, Windows 2016 Domain Controllers
    • 192.168.30.131
    • 192.168.30.132

VLANs

1VLAN1-MGMT192.168.0.0/24
10VLAN10-Office192.168.10.0/24
20VLAN20-Media192.168.20.0/24
30VLAN30-Servers192.168.30.0/24
50VLAN50-Wifi192.168.50.0/24
  1. Set up VLANs in Omada
  2. Configure VLAN1_MGMT
NameVLAN1_MGMT (Management)
PurposeInterface
LAN InterfacesSelect All of them
VLAN1
Domain Nameyourdomain.com
Gateway/Subnet192.168.0.1/24
IGMP SnoopingUnchecked
DHCP ServerChecked
DHCP Range192.168.0.50 – 192.168.0.99
DNS ServerManual – 192.168.30.131, 192.168.30.132
Lease time120
Default GatewayManual – 192.168.0.1
DHCP Omada ControllerBlank
Legal DHCP ServersUnchecked
Legal DHCPv6 ServersUnchecked
DHCP L2 RelayUnchecked
  1. Do the same for the other VLANs.
NameVLAN10-Office
PurposeInterface
LAN InterfacesSelect All of them
VLAN10
Domain NameYourdomain.com
Gateway/Subnet192.168.10.1/24
IGMP SnoopingUnchecked
DHCP ServerUnchecked
Legal DHCP ServerUnchecked
Legal DHCPv6 ServersUnchecked
DHCP L2 RelayUnchecked
  1. Profiles are created automatically when VLANs are created
  2. Update/Verify profile VLAN1-MGMT
  1. Update/Verify profile VLAN10-Office, and Media and Server

 Switch Config

  1. Select Switch from the Devices page
  2. Each switch should have an uplink to the router.  Choose the same port on each switch.
  3. Each switch will have a management IP on VLAN 1
  4. Use the “ALL” profile for the Uplink port.
  5. Assign the Other VLAN profiles to the rest of the ports as needed to support attached devices

Configure Interfaces

  1. Select Config–>VLAN Interface
  2. Turn on all interfaces

This function is what allows DHCP to flow from your DHCP servers down to the ports on your switches.

  1. Select each VLAN Interface and edit it

VLAN1-MGMT – Management Network

Management VLANChecked
IP Address ModeStatic
IP Address (This will be the IP address assigned to the switch)192.168.0.12
Subnet Mask255.255.255.0
Default GW192.168.0.1
Primary DNS192.168.30.131
Secondary DNS192.168.30.131
DHCP ModeNone
IPV6Unchecked

Set up Remaining VLANS

  1. Note that each VLAN has its own IP
  2. Note the Last Octet will be different for each Switch
    • Office Switch is xx.xx.xx.2
    • Media Switch is xx.xx.xx.3
    • Server Switch is xx.xx.xx.4
VLAN10-OfficeVLAN20-MediaVLAN30-Servers
Management VLANUncheckedUncheckedUnchecked
IP Address ModeStaticStaticStatic
IP Address192.168.10.2192.168.20.2192.168.30.2
Subnet Mask255.255.255.0255.255.255.0255.255.255.0
DHCP ModeDHCP RelayDHCP RelayDHCP Relay
Server Address192.168.30.131192.168.30.131192.168.30.131

  1. Note the IP Address.  This will be the IP for the appropriate VLAN.
  2. Note the last octet.  This will be the same for each Interface on each switch
  3. Each VLAN ends up with an IP on the switch for that VLAN.

Here is a sample for 3 switches:

SwitchVLANVLAN Interface IP
Office1192.168.1.12 – admin IP
Office10192.168.10.2
Office20192.168.20.2
Office30192.168.30.2
Media1192.168.1.13 – admin IP
Media10192.168.10.3
Media20192.168.20.3
Media30192.168.30.3
Servers1192.168.1.11 – admin IP
Servers10192.168.10.4
Servers20192.168.20.4
Servers30192.168.30.4

Once these settings are applied, you should be able to provide DHCP to all VLANs (excepting the manangement VLAN) from a source such as Windows or Linux DHCP servers.

Each switch ends up with a virual interface for each VLAN to route this. (xx.xx.xx.2, 3, 4, etc.)

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