IP helper Snooping

[almatel]

Hi all,
reference to the attached Network topology :
First:
the configuration is running ok!, but if there is a better idea to improve it , please advise.

Second:
to drop duplicate ip addresses that are coming into the
Dist. switch using dhcp snooping Ip Source Filtering feature do I have to enable it on the the distribution Switch for each vlan:

ip helper dhcp-snooping (for each vlan ) enable
and :
ip helper dhcp-snooping binding enable
ip helper dhcp-snooping port 1/47 trust (DHCP Server)
ip helper dhcp-snooping port 1/46 trust (OXE)
ip helper dhcp-snooping port 1/30 trust (A6450)
ip helper dhcp-snooping port 1/45 trust (stand alone A6850E)
ip helper dhcp-snooping linkagg 2 trust (Stack)

and do the same on ports basis + Enable Ip-source filtering like:

A6850E stand alone switch:


ip helper dhcp-snooping (for each vlan ) enable
ip helper dhcp-snooping binding enable
ip helper dhcp-snooping port 1/48 trust
ip helper dhcp-snooping ip-source-filter (for each vlan ) enable

A6450 switch
ip helper dhcp-snooping vlan 2 enable
ip helper dhcp-snooping binding enable
ip helper dhcp-snooping port 1/24 trust
ip helper dhcp-snooping ip-source-filter vlan 2.

Stack Switches

ip helper dhcp-snooping (for each vlan ) enable
ip helper dhcp-snooping binding enable
ip helper dhcp-snooping linkagg 2 trust
ip helper dhcp-snooping ip-source-filter (for each vlan ) enable


please advise.

BR