Question : Moving DHCP superscope and vlans

Ok on of the DC's is acting up so it is being replaced currently it is acting as the DHCP Superscope.  There are 4 VLAN's connecting to the superscope I have changed the IP Helper address on the Sonicwall Firewall that is handeling the VLAN's but only one of the scope ranges is handing out dhcp.  If I authorize the old dhcp server but leave the ip helper on the firewall pointing to the ip of the new dhcp server the vlans that couldn't get a dhcp renew can.  So I am guessing that soething else on the network is acting as a relay agent but i can't figure out what it is.  so if any one know of some command line tools or utilities that could help me trace out where the dhcp relays are that would be a big help.

Answer : Moving DHCP superscope and vlans

Ended up that the HP Procurve switches have a DHCP relay auto discovery so instead of trying to get the switches to update we just changed the IP address on the new server to match the old DHCP server.