IP helper-addressing, VLANs on 3550 switch

[gadget207]

Have had trouble getting dhcp addresses from NT4 server to clients in VLANS. All VLANS configured with helper address of NT4 server which resides in management VLAN. Do I need to add persistent routes to NT4 server for each vlan's gateway address for this to work ?

[jeff]

Try adding " ip helper-address x.x.x.x" where X is your PDC, to each VLAN interface .

[gadget207]

yes...already done...with all VLANS as i have said....I think this issue may have to do with the DCHP ACK getting sent back to the proper gw interface....am I correct here?

[jeff]

Question: Your switch running Enhanced Multilayer Software Image (EMI)

so can do the Layer 3 routing ?

[gadget207]

yes, with IP routing enabled. I tested using static addresses in each VLAN and could ping all other equip in all VLANs....It was just DHCP configured clients not getting addresses...

[jeff]

So its not a routing problem...

Any possibility a Firewall or ACL is blocking UDP to ports 67 and 68??

[glen.grant]

Also make sure on your switches that are hosting your dhcp clients that portfast is on , possible clients are timing out . Also you might be able to do a debug on your 3550 to see what is going on .

[gadget207]

Thanks!....will enable portfast on all access ports, and enable debugs...btw....no firewall between VLANS....