Yeap, sadly there are recommended "dont's" when using P2V
Check this VMware doc about best practices/do's and dont's: HERE (its a pdf)
Also, once you start to setup P2V
1. Disable Firewall
-Disable Firewall completely
2. Run as Administrator the application
-Simply Right-Click and RUN as Administrator
3. Make sure if your host is 5.5 your p2v converter version is 5.5 as well
4. If you don't have a vCenter server use VM Version 9 in the conversion setup
-v10 requires vsphere web clent or vcenter server
5. IMPORTANT: in the p2v conversion setting UNTICK the connect at power on on the NIC to avoid conflict
-since p2v requires that your physical server and esxi server meet, thus if you forgot to untick it, you'd expect network conflict
6. READ THE BEST PRACTICE DOCUMENT 
-Of course, test your P2V'd physical server, create an isolated network in your host and test it out. if no issues occur then you're okay
TIP: Still keep the physical server for a few months or so, we may never know issues may occur if you ever plan to put it live in your network ^_^