So, we have this amateur kind of setup in school:
• DHCP Server in a Private DMZ that is connected to an ASA Firewall
• ASA Firewall has subinterface for the network 172.240.30.0/24, .1 is the GW.
• That network consists of 2 units of Layer 3 switches, namely, Switch 1 and Switch 2, both are ACCESS layer switches.
• DHCP pool was enabled in Switch 1.
• This setup is working fine.
Scenario:
• We are trying to migrate the DHCP pool in Switch 1 to our DHCP Server located in our Private DMZ.
• First, we failed to migrate it, although IP helper was configured in the switch's data VLAN and DHCP pool was deleted already in Switch 1 until our mentor told us that we have to configure IP routing in Switch 1.
• All went well for those devices directly connected to Switch 1, but not for Switch 2.
• And then I went and tried to configure IP helper as well in the same data VLAN we configured in Switch 1 to Switch 2, and it worked.
After that, I'm thinking why would it behave like that, and was assuming that the Switch 1 became Layer 3 device so that it wouldn't take any broadcast from any hosts (DHCP Discover) unless it was unicast/multicast. Thus IP helper will solve the problem.
Question is, is it normal for layer 3 switches to behave that way? I mean, it also possesses layer 2 functionalities still while having capabilities of layer 3 right? May I know your insights?
Also, are there any other much better setup than we did in our migration? :)
Thank you and hoping for your immediate response!
