topic Re: dhcp on L3 or Vlan interface in General Topics

dhcp on L3 or Vlan interface

roma — Thu, 16 Mar 2023 16:37:22 GMT

Using our pa firewall connected to our ISP modem (in bridge mode) its working fine. But I have a zone called guest that I want to have dhcp clients on that will be separate from my trust network. I want to be able to have those guests on DHCP from the Palo. Do I configure that guest interface as L3 or Vlan?

Re: dhcp on L3 or Vlan interface

OtakarKlier — Thu, 16 Mar 2023 17:07:19 GMT

Hello,

I prefer to have my physical interfaces as layer 2 and have the layer 3 interface as the vlan, but its only my preference. Your DHCP will be configured on the interface you choose as your layer3 interface for that vlan.

Regards,

Re: dhcp on L3 or Vlan interface

Raido_Rattameister — Thu, 16 Mar 2023 17:21:11 GMT

If it is small location where you don't have dedicated switch and you need multiple Palo physical interfaces to be in same subnet then it makes sense to use Layer 2.

Otherwise Layer 3 is always simpler and cleaner setup.

Re: dhcp on L3 or Vlan interface

roma — Thu, 16 Mar 2023 17:47:51 GMT

There is a dedicated L3 switch and the guest network will be separate from our inside LAN. So I have to make L2 vlan on the L3 switch and have that L2 vlan connect to the PA guest interface?

Re: dhcp on L3 or Vlan interface

Raido_Rattameister — Thu, 16 Mar 2023 18:02:02 GMT

I assume that you will configure guest network default gateway IP on Palo and not on switch so your switch' L3 capability don't play any role here.

But in general yes your steps are correct.