ESX Server 3i Local UI Can Display Random Messages When a DHCP Server Sends a NAK Packet
Details
If you use the local UI of your ESX Server 3i host to configure network settings and the DHCP server sends a NAK (Non Acknowledged) packet, some random messages might appear on the screen and interfere with the UI display.
Solution
Ignore the messages and press Enter to leave the message box. If you still cannot use the local UI, press Ctrl+C to restart it.