Saturday, June 8, 2013

No CDP on UCS ESXi vmnics?

I spend most of my professional life digging through UCS and vSphere configurations. Many times I find that UCS has been configured to work, but not always work well. Here's a quick example:

In the process of reviewing the host networking config for some new ESXi hosts, I wanted to see what upstream switches they were connected to. Normally, I'd just click on CDP to see this information. But when I looked, here's what I saw:

Fresh out of CDP.
It's an easy thing to fix. Here's how:

  1. Log into UCS Manager
  2. Navigate to the LAN tab, and locate the Network Control Policies (path is LAN | Policies | root)
  3. Expand this item to see all of the policies that have been defined.
  4. To see which service profiles are using each policy, select the policy, then click Show Policy Usage. This is a great way to confirm how your changes will affect your hosts. It also works for all other policies, FYI.
  5. Find the Network Control Policy that your ESXi hosts are using, and take a look at the settings. Is CDP enabled?

  6. Click the Enabled radio button, then Save Changes. That's it!
Your hosts will not need a reboot, and the vNICs won't experience any disruption in their operation as a result of this change. The only difference is that now, you'll be able to collect CDP data in your vSphere Web Client, like this:

CDP in the house.

Cisco UCS can be a challenging platform to work with, especially if you're unfamiliar with network, server, and virtualization concepts (I should lump storage in there, too!). If you've got questions, or are looking at transitioning to Cisco UCS, consider contacting Chesapeake NetCraftsmen (that's where I work!). I've done enough UCS installs and upgrades to know how to avoid common pitfalls, especially when running vSphere on UCS.