UDPHELPER, Clients on VLANs unable to get DHCP Addresses

[Soleyman]

Hi

I have a 3Com 3CR17500-91 Layer 3 Switch.
I need to some information about using udphelper and dhcp setting on this type switch

you can see my scenario from :

http://81.93.39.40/System/Images/3ComUDPHelper2.jpg

Type IP address Subnet mask State VLAN ID
------------------------------------------------------------
Primary 192.168.100.14 255.255.255.248 Up 1
Primary 192.168.100.49 255.255.255.248 Up 2
Primary 192.168.100.57 255.255.255.248 Up 3
Primary 192.168.101.64 255.255.255.192 Up 4
Primary 192.168.101.129 255.255.255.192 Up 5
Primary 192.168.101.191 255.255.255.192 Up 6
Primary 192.168.102.1 255.255.255.0 Up 7

UDPHelper1:
Windows 2000 Active Directory DHCP
IP = 192.168.100.50 Gateway 192.168.100.49 (VLAN2)
% 80 DHCP for following VLAN Scop : 4,5,6,7


UDPHelper2:
Windows 2000 Active Directory DHCP
IP = 192.168.100.60 Gateway 192.168.100.57 (VLAN3)
% 20 DHCP for following VLAN Scop : 4,5,6,7

all VLAN are unttaged
Spanning tree and IGMP disable (recommended by 3com @

http://knowledgebase.3com.com

search for DHCP)

Clients on VLANs unable to get DHCP Addresses
and report : DHCP Server unreachable

Thanks
Soleyman