ESX standard swtitch promiscuous mode - must the guests be on the same host?

Hey all,

I am setting up packet sniffing on our ESX environment.

I can tell from documentation that the virtual machines that generate the traffic I want to sniff must be on the same physical host (Cisco 1000v).

However I cannot find any details about a standard swtich.  Do the guest machines also need to be on the same host?