I have looked through past posts with out finding the resolution to my problem. Hopefully some here who knows more than I do will be able to help me out.
So here it goes....
I have a multilayer switched network.
-Dual 4507s acting as the core/distribution
-3750s connected to the collapsed backbone acting as L-2 access edge switches.
The 3750s are segmented with different vlans for each floor of the bldg.
The SVIs on the ccore 4507s have an ip helper address to relay the dhcp broadcast traffic to the dhcp server in the datacenter. This configuration is working fine. Where I'm running into problems is when end user moves from floors (into confrence rooms )to different vlans with their laptops, the dhcp address lease is not being deleted out of the dhcp database. so when the dhcp client connects to the new vlan with a different subnet, the ip address is of course in correct for the vlan. and when a "ipconfig /release & /renew" is performed the ip address is renewed. I'm guessing because of the mac address associated with the ip address in the dhcp database is the reason for this. so to get the dhcp functionality working i have to go into the dhcp server database and delete the lease and then it works. Or i have to wait for the lease to expire.
So my questions are:
1.) is there a better way that i should set this up?
2.) If i have architected the networking pieces correctly is there a way to make this work more efficiently?
4507 One VLAN
description "2nd Flr Data"
ip address 10.1.120.2 255.255.255.0
ip helper-address 10.1.3.4
standby 120 ip 10.1.120.1
standby 120 priority 110
standby 120 preempt
3750 One port config
switchport access vlan 120
switchport trunk encapsulation dot1q
switchport mode dynamic desirable
switchport voice vlan 121
Sorry, my hands were moving faster than my mind..... I said that you may have issues with your DNS server, I meant DHCP. I am by no means an expert on DHCP servers, but have been biten by them many times. One thing I have seen is improper static associations of MAC addresses to IP. The fact that by going to the DHCP server to fix this is further indication that you have a problem there.
Can you get a packet capture from the workstation when doing the release/renew. Look to see if the DHCP server is responding with the proper offer. This should isolate the problem.