Using the WANem WAN Emulator Virtual Appliance

During preparation and preliminary information gathering for a new internal project, I had a need to emulate various networking conditions and scenarios. More specifically I’m looking at the possibility of running the vCenter Client over high latency satellite links, with varying bandwidth availability and even packet loss scenarios.

Obviously the best way of testing this, in a controlled environment, is to use some kind of WAN emulator that lets you control the various networking characteristics. WANem is a free WAN emulator and it even comes as a VMware virtual appliance.

Setup is pretty straight forward, and I won’t get into the detailed instructions at this point. If someone requests it, perhaps I’ll make a HOWTO post later on.

After the WANem Virtual Appliance has been started and setup in your network environment, all you have to do is to route your traffic through it. In my test environment, I decided to route all traffic between my local computer and my vCenter Server through the WANem appliance. Doing so is pretty straight forward; Open up a cmd window, with administrator privileges, on your local computer and use the route command to force traffic through WANem:

the command itself is:
route add {destination IP} mask 255.255.255.255 {WANem IP}

To tune the network properties of the traffic going through WANem, open the WANem admin page in your browser and work some magic. The screenshots below are from the advanced tab:

WANem Advanced Mode Screenshot #1WANem Advanced Mode Screenshot #2

As a simple test, I decided to add 500ms latency (delay time) and a packet loss of 25%, and as you can see from the video below it works as expected


(Video has been scaled to fit, watch it in fullscreen mode for details).

Conclusion

If you need to test out how your applications or networking infrastructure works when issues like latency, jitter and even dropped packets affects your clients, WANem seems like an easy and free route (pun intended) for testing purposes.

SolarWinds VM Console

SolarWinds has released a new free vSphere tool called SolarWinds VM Console.

    Free VM Console Highlights:

  • Bounce (shutdown & restart) VMs without logging into vCenter or vSphere
  • Get end-to-end visibility into your VMware environment—from vCenter through ESX hosts to VM guests
  • Track the real-time up/down status of your VMs from your desktop — without logging into VMware apps
    Additional VM Monitoring Features:

  • Take a snapshot of your VM prior to shutdown
  • Search on VM names or IP addresses
  • Use your vCenter/vSphere credentials to view a top-down hierarchy of your virtual environment

I’m not sure why you as an admin might want to use this tool instead of the vSphere Client, but in environments where you have delegated control over certain VMs (like a test environment etc.) it might be a useful addition to your tool-belt.

vCenter Update Manager to lose it’s fat

Dwayne Lessner who runs IT Blood Pressure, has written a guest post on GestaltIT called Is My Favourite VSphere Tool Is Going Away?

In his article, Dwayne talks about vCenter Update Manager 4.1, and the fact that it seems to be the last version of the tools that will allow you to patch your Windows and Linux guests:

VMware vCenter Update Manager Features. vCenter Update Manager 4.1 and its subesquent update releases are the last releases to support scanning and remediation of patches for Windows and Linux guest operating systems and applications running inside a virtual machine. The ability to perform virtual machine operations such as upgrade of VMware Tools and virtual machine hardware will continue to be supported and enhanced.
VMware vSphere 4.1 release notes

Dwayne talks about this as being a bad thing, and that’s where I disagree. I have never understood why VMware saw it as their job to patch the operating systems the guests are running, and I have yet to see anyone actually use this feature. Obviously I was wrong, someone does indeed use it, but I really can’t understand why.

I’m a keen believer in doing what you know, and doing it well. Let “native” patching solutions take care of the guests, Windows Server Update Services (WSUS) comes to mind, and leave vCenter Update Manager (VUM) to take care of patching your VMware products.

I wouldn’t mind seeing vCenter Update Manager (VUM) extended into patching the VMware Workstation, Fusion and Player installations your enterprise might have, but I really think that losing the fat that is guest OS patching can only be a good thing.