DHCP Problem

[jimhalliwell]

I have two core switches one is a Enterasys 8600 and this is connected by gigabit connection to our Cisco 6500.We have a Vlan 20 with an ip range created on the 8600. I have passed this vlan (layer2) over the link to the 6500 and have a laptop on an access port with a satic ip in the vlan 20 range, this works.However DHCP will not! DHCP works for this vlan on the 8600 but it seems to be stopped by the 6500, because its layer two I cant add an iphepler. Do you guys have any ideas?

Thanks Jim.

[leonvd79]

If I am right you are plugged into the 6500 with a laptop and can't obtain a lease. With a static IP address you have verified the connectivity to the Enterasys 8600 and beyond, right?

From the switch perspective it's all layer 2. The DHCP request broadcast should reach the DHCP in VLAN20. Observe this by monitoring the traffic passed between the Catalyst 6500 and Enterasys 8500 switch.

The Catalyst 6500 is a advanced switch which support DHCP snooping features, however it's not likely this is enabled by default. Please verify basic connectivity and post configuration snippets if possible.

[jimhalliwell]

If I am right you are plugged into the 6500 with a laptop and can't obtain a lease. With a static IP address you have verified the connectivity to the Enterasys 8600 and beyond, right? Ye this is correct we have connectivity to 8600 and can ping the DHCP server.

From the switch perspective it's all layer 2. The DHCP request broadcast should reach the DHCP in VLAN20. Observe this by monitoring the traffic passed between the Catalyst 6500 and Enterasys 8500 switch. I will do this

I will get back. We also have sites connected to the 6500 ie vlans on the 6500 which get to the same DHCP server and obtain addresses no problem its just this layer 2 situation that has problems.

[nethelper]

Hello,

what IOS or CatOS version are you running on the 6500 ? A bug check might be useful...

Regards,

Nethelper