cyborgworkshop.org

ESXi 3.5 only allows 4 virtual NICs to be assigned to a virtual machine. For many uses, that’s just fine, but my latest overly complex home network requires for 5 wireless network, 3 wired networks, 2 storage networks and a public hotspot type network. That’s no less then 11 network interfaces. Fortunately, I have the hardware to handle 802.1q vlans. Unfortunately, vmware doesn’t seem to like passing 802.1q headers through the vmnics and into the outside world. I spent a fair amount of time with a sniffer trying to figure this situation out and came across a white paper that saved my bacon. When you create a virtual interface in the VI Client, you have to set it to use vlan 4095 if you plan on using it as a pass-thru trunk interface. If you don’t, none shall pass. How frustrating is that?
Hey VMWare, consider this a feature request. How about a flipping check box labeled “Pass-Thru Interface” instead of a white paper buried on under the interwebs?

update The latest ESXi configuration guide mentions this on page 30 http://www.vmware.com/pdf/vi3_35/esx_3i_e/r35/vi3_35_25_3i_server_config.pdf

nmap is a really excellent  network tool that most folks are familiar with.  I find that I tend to use it to first discover hosts on a network and then to get more specific information from a targeted node. The first part of that discovery is the ping sweep, which can be done thusly.

nmap -sP 192.168.1.1-254

Pretty simple. 192.168.1.1 is the start IP and 192.168.1.254 is the stop IP. nmap will ping every address in that range and return the IP of hosts that respond.