Guest XP can't see vCenter

Hello everybody.

My config is as follows:

- ESX1 (192.168.1.150)

- ESX2 (192.168.1.160)

- vCenter (192.168.1.50)

- Domain Controller (192.168.1.10)

All of them joined by vmnet2 (Workstation Host-Only).

Let's focus on ESX1.

- I have created vSwitch0 with vmnic0. This switch has 2 Port Groups: VMKernel (Management Network) and Virtual Machine.

- I have created vSwitch1 with vmnic1. This switch has 1 Port Group named by me ("Production").

I create a guest VM with WinXP and assign the "Production" network. Once logged in, I issue ipconfig /release and ipconfig /renew, giving me the IP 192.168.1.135 and no GW.

My questions are:

1. ¿Who is assigning it that IP? ¿Why .135?

2. ¿Why can I ping successfully to ESX1 and ESX2 but not to vCenter? In fact, XP should be isolated from ESX2 and vCenter.

3. In vSphere console, "Management Network" is the only that has "IP Settings" tab (apart from "General", "Security", "Traffic Shaping",...). ¿Why is this so?

I attach a brief layout of my setup.

Please help.

Thank you!