While troubleshooting VLAN connectivity on UCS in end-host mode with multiple uplinks, it is be good to know which uplink is the designated receiver (listener for broadcast and multicast) for which VLAN. This will be useful when you have L2 connectivity issues, where 1 or more VLANs are having issues going outside the Fabric Interconnects.

Considering the length of the command to find the designated receivers, I haven’t memorised the command itself, but the which command to find it:


Ciscos UCS Server proposition is rocking the market (“Report: Cisco Achieves Top Rank in Americas’ x86 Blade Server Market“) of datacenter computing. Their management software and profile concepts are, dare I say it, the best out there. As an engineer, it is a delight to work with UCS. The minimal amount of effort it takes to deploy a massive computing environment is mind blowing.

The thing that makes UCS awesome, is also the thing that usually weighs it down in small deployments; the Fabric Interconnect (FI). The UCS Manager that runs on the fabric interconnect makes the entire … Read more


When using a Cisco UCS C-Series rack servers in it’s standalone form (not connected to Fabric Interconnects, so not managed through the UCS Manager), you can boot it using a few options: local storage, fiberchannel connected storage, PXE boot and iSCSI.

When you don’t have fiberchannel at your disposal for central boot, iSCSI will do just fine.

The configuration inside the C-Series CIMC is a bit hidden though, here’s how you do it. Login to your CIMC and follow this procedure:

  • 1. Go to Inventory
  • 2. Select the ‘Cisco VIC Adapters’ tab
  • 3. Select the ‘vNICs’ sub-tab
  • 4. Click ‘Add’
Read more

The UCS Inventory Script (UIS) is a tool written in Powershell (using the awesome Cisco Powertool plugin) which I’ve been using for a while in my job, gathering all the configuration data at the end of a build.

That way, I had a reference containing every detail of the UCS configuration to look back to. When an issue came around after we left, we could check back and see in what state we left UCS and if all the proper configuration was done.

Recently, I’ve started updating this script to include everything that I could think of and started adding … Read more


If you use UCS Manager, this has probably happened to you once or twice. Something happened on your UCS environment and you need to get KVM access to a few blades to get things working again. Then you discover one of your colleagues has left his desktop or terminal server session running with a KVM sessions open to the blades you need and you get a “Send sharing request?” dialog. Send all the sharing requests you want, that colleague is enjoying his weekend and won’t respond to them.

The way you can get around this is to reset the KVM … Read more


The UCS Central appliance is on it’s way to be a proper centralized management platform for multiple UCS domains, but it’s not quite there yet. There are little simple things missing, such as custom SSL certificates. I had to get UCS Central using a proper SSL certificate the other day and couldn’t really find anything on how to do it. After figuring out how to do it, I decided to document it here!

I’m not getting into how you can generate a SSL private key, there are plenty of other tutorials covering those things. You’ve got two options; generate the … Read more


Brad Hedlund‘s blog is one of my favorite sources of excellent UCS (and other general) material. I just found the exceptional UCS videos, which deserved a re-share.


Part 1 – The Physical Architecture of UCS

In this video we take a look at the physical network architecture of Cisco UCS and incorporate the new capability of connecting both blade and rack mount servers to UCS Manager.


Part 2 – Infrastructure Virtualization & Logical Architecture

Here we look at how Cisco UCS virtualizes every significant component of the physical architecture; switches, cables, adapters, and servers. Then we look at how … Read more