Multiple subnets with one VMware ESXi host

As we’ve moved more and more of our critical infrastructure at The Chapel to the virtual world, I’ve struggled on occasion with the issue of setting up network cards in VM’s to work on different subnets.

This became a real issue when we migrated from our Cisco phone system to our virtualized MiTel phone system. All was good until I needed to setup the “MiTel Boarder Gateway” which acts as a firewall and SIP gateway for the phone system. Since I had to get this up and running quickly I just installed another network card then mapped it to a virtual switch in VMware and mapped the second NIC in the VM to that virtual switch.


This approach however is not very efficient or redundant. It also takes up valuable NIC’s and switch ports. My plan is to update this configuration with what I’ve learned when setting up our print server to work with FingerPrint which I’m going to detail below.

How to setup Vlan tagging in VMware ESXi

  1. First, you need to have a working ESXi host. The setup isn’t that hard but is more than I’m going to go into here.
  2. Setup your switch port(s) that connect to the server as a “trunk” in Cisco speak with a “Native Vlan” set to what a majority of your servers use. That way you don’t have to setup tagging on every vNIC.
  3. If your looking to have a server that needs to talk to two different subnets like a firewall or my print server running FingerPrint, add another Ethernet adapter to your VM and assign it to your default network. Mine is “VM Network”.
  4. You need to check that the Virtual Network on your primary vSwitch allows all Vlans. By default it is set to “None(0)“.  Set it to “All(4095)” or just the ones you want.
  5. Now, start up your VM and log in. Navigate to the Device Manager and select the network card you want to configure a different Vlan on.
  6. Once you configure the tagging, make sure that you have the IP addresses setup correctly. For a firewall type VM, you will have different IP’s and gateways on different subnets. If you have a server connecting to two private networks, only set a default gateway on the “Primary” network. Windows doesn’t like it if you set different gateways to the same routed network.

That’s it. Now your servers can use different and special Vlans when needed and you don’t need to add another NIC or vSwitch each time. In my case, it allowed me to easily setup FingerPrint to communicate with our wireless network with the Bonjour protocol.

For my friends that are more versed in VMware than I, please post your comments and questions. I’m always interested in what others are doing or what the “Right” way is.

Apple AirPrint and FingerPrint

So you have a shiny iPad or iPhone and want to occasionally print. Sounds simple, right? Well Apple has your back and has come out with a great “New” feature called AirPrint that will fix all of that. That is if you have one of the few new printers that have AirPrint.

A lot of companies are seeing more iOS devices on our networks and more users who expect new features that Apple comes out with to just work. They have little patience for us or the market to align ourselves with the Apple way of doing it. We also have some expensive, high efficiency, and feature rich printers and copiers on our network that we can’t afford to just replace.

Our first solution was a hack program called “AirPrint Service for Windows” that worked well until iOS 5. Then it broke.

There were some other iOS apps that let you print to network printers but they cost money and you have to pay & install it on every device.

Earlier this month I found a program called “FingerPrint”. You can check it out at http://www.collobos.com/  They have a Windows and a Mac version and also provide a free one week trial. If you still like it after the trial, you can buy it for $10! I wondered just how well a $10 application could work but read on.

After running the quick install file and selecting the printers I wanted to share, I was up and running!


It also has a cool feature that I’ve yet to try that allows you to “Print to DropBox” where you can tie it to a DropBox folder. This could work on a personal computer but I don’t see it working on a network print server well.

Once things are installed and working, connect your iPad or iPhone to the wireless network (it has to be same subnet though. Stupid Bonjour!), and your printers will show up in the “Select Printer” dialog. 


That’s it. After the free trial I bought it. It’s working great so far. I’ve not tested this on multiple print servers on the same subnet yet so I’m not sure how that would work.

There is one civet though. Your print server has to be on the same subnet as your wireless. This poses a problem for most of us that have an enterprise wireless solution and have it on a different subnet. During the trial period, I setup a Linksys AP on the same subnet as the server and it worked fine. But it kind of defeats the ease of use I was going for when people have to connect to another wireless just to print.

I’ll address how I got around this limitation in my next blog post about connecting virtual servers in VMware to multiple subnets.

Read about it here.