I have a 3550 XL with the Enhanced image on it. I have 10 other 2900/2900 XL swtiches attached to it. I have created Vlans for each port, each VLAN is a seperate IP Network Segment and I have DHCP Scope for each network. WHen I activate any of the VLan's, the new network does not receive a DHCP address. I have the IP Helper address configured to point at our DHCP server which is in the core switch. What am I missing?
Do you have portfast enabled on client ports? If not enable it. Also disable trunk negoatiation by using "switchport mode access" command under the interfaces where you have client PCs. If problem persists, I suggest you use capture a sniffer trace to troubleshoot
The CLient pc's are all on the 2900's. They are already set to have portfast enabled. If I have just the port on the 3550 Set as the Vlan, I don't believe I need any configuration on the 2900's. The Only Vlan that is being set up is the Port on the 3550 to segment out the network. I have done this before with a 6509 and 3com switches, where all I had to do was configure the Vlan on the 6509, with the IP address and Helper address and it worked. What is different?
If you are not trunking on the 3550 to the 2900XL, then it is OK- Seems like you are having the problem with the DHCP rather than anything, please capture the sniffer traces and see if the client is receiving the request if the switch 3550 is configured with ip helper address.
Also check if you assign the static ip address, can you route across the vlan.