I am working in a small company with 70% of PCS and 30% Macs. Currently the place has got about 350 computers with 1700 users. Recently i used a special network monitoring software called wireshark to monitor the network. Wireshark gives me a clear picture of what is going on with the network. I found a strange protocol named MDNS runing through my network. What is MDNS? Does it cause network trafic? from where do you think MDNS coming from? according to wireshark software, most apple machines use MDNS