DHCP over Vlans working on cisco not on HP 2650

[Ryan1979]

We have a cisco 3750 stack with about 10 vlans on it acting a ‘router’ to route vlans to a single DHCP server with a scope for every vlan.

This works great for the cisco 2950 edge network switches (which we were using previously) and is really easy to setup however for the procurve 2650’s all I seem to be able to do is get a DHCP from the management scope, not the vlans scopes. I have setup 2 vlans (the default –vlan1) and also vlan 18. Vlan 18 is assigned ports 1-48 and they are untagged. Ports 49 and 50 are the fibre ports (only 49 is currently connected) and are on vlan 1 and vlan 18 with tagging on both. I have also on the HP 2650 setup a ip helper address (which I didn’t think I needed to do on the edge switches). Any thoughts or ideas would be greatly appreciated.

[Mohieddin Kharnoub]

Hi

Usually in multiple vlans environment, you need to add a ip helper-address, and one more thing, you need to be sure that in your DHCP scope for Vlan18, that the router parameter should be the Vlan18 ip address on the routing switch.

Also, i prefer you untagg port 49-50 for Vlan1 and keep it tagged for Vlan18.

If you connect a pc to any port 1-48 that is untagged to Vlan18, and assign a static ip address, try to ping your DHCP server, and your gateway (vlan18 ip address on the routing switch).

If that didn't help, attach the config of this switch configuration here, so we can worked out together.

Good Luck !!!

[Ryan1979]

Thanks for your help Mohieddin

I already have a ip helper-address assigned and I have also previously added the router for the switch in the DHCP advanced options. If I use a cisco switch (like a 2950) I dont have a problem, only with the HP.

Dumb question,. How do i export the switch config for you?

Thanks in advance

[Ryan1979]

here is the startup config, I hope thats all u need thought its very small.

Thanks in advance

[Ryan1979]

This is also the 3750 cisco switch config to show the vlans etc.

[Ryan1979]

Oh and lastly, Static IP on the 18 subnet I still can not ping the gateway or the DHCP server.

[psycho.chicken]

is your dhcp server on this switch, or out one of teh 49 or 50 ports on another switch?

[psycho.chicken]

what is teh dhcp servers default gateway? it should be the vlan ip of the vlan it belongs to...

[Ryan1979]

the default gateway is a windows 2003 server on 10.12.7.252. It is hanging off the core switch.

Port 49/50 are fibre links to the core gig switch.

[psycho.chicken]

the dhcp server's default gateway should be it's vlan's IP

example

my vlans are
10.3.10.1 /24
10.3.10.1 /24

so any client that gets a 10.3.10.x also gets 10.3.10.1 as it's default gateway

on the switch that has ip routign enabled it's default gateway should be your router

i thin what's happening is the ping request is makign it to the dhcp server, but not back...

try correcting the default gateway's