12-10-2013 11:39 AM - edited 12-10-2013 01:52 PM
I recently moved my L3 interface to my firewall.
Clients are no longer receiving IP addresses as the IP Helper was removed along with the router-interface (ve 320)
How do I configure my VLAN 320 with the details of my DHCP Server?
I am unable to add IP Helper without a router-interface.
Old config below
interface ve 310 ip address 10.3.10.1 255.255.255.0 ! interface ve 320 ip address 10.3.20.1 255.255.255.0 ip helper-address 1 10.3.20.13 !
12-14-2013 02:18 PM - edited 12-14-2013 02:20 PM
The helper address makes only sense in L3 environments cause it forwards UDP broadcasts like DHCP etc. into other IP segments.
Usually UDP broadcasts are always limited to the L2 broadcast domain and now forwarded through routing interfaces.
If your switch ve routing interface was removed from the switch and transferred to a firewall in that IP segment you need to configure the helper address now on the firewall, cause this device has to forward your UDP broadcasts to the target now.
Your ICX6610 is not involved anymore in L3 routing if the ve interface is removed in that specific vlan now.
Btw. your helper config above on ve 320 is completely useless anyway, cause it points to a target ip address in the same vlan / l2 domain. Usually for vlan local ip addresses this is not needed cause no router interface need to be passed.