UPDATE BELOW: UPDATE 2 BELOW: FINAL Solution
I have a brand new HP EliteBook notebook 8560p running Windows 7 64bit. I plug it into a small Dlink di-604 router, it is currently configured with DHCP and gets ip address 192.168.1.100, ip address of the router is 192.168.1.6. I plug a second notebook in and it gets ip address 192.168.1.101. This is all that is plugged in and the router is not connected to the WAN. If I go on the second notebook (.101) and ping the first (.100) it does not respond. If I try pinging 192.168.1.2 ( a non existent IP address) I get a response and I notice in the arp cache that the MAC address of the first machine is listed for ip 192.168.1.2 and 192.168.1.100. No where on the first machine is 192.168.1.2 defined, nor has it ever been, this is a bone stock straight out of the box notebook. ipconfig /all responds with 192.168.1.100 and 192.168.1.150 respectively.
I tried setting the first machine to a static address 192.168.1.150. Again same results, cannot ping .150 however response to ping .2. , .2 and .150 show up in the arp cache of .101 with the same the same MAC address.
Some observations: when responding to pings on .2 it is not consistently <1ms or less it is usually a fairly high ranging number, anywhere from 4ms to 30ms, which is really odd considering both are connected to the same switch.
I have tried multiple routers, dlink, sonicwall, and another dlink. Same result on all
If I use a different subnet for the entire lan, like 192.168.0.x instead of 192.168.1.x there is no problem what so ever it works and responds as expected.
Anyone ever see anything like this before?
UPDATE: I had a continuous ping running to this mysterious IP address 192.168.1.2 and when i rebooted the troubled machine the ping started back up as soon as the BIOS came up. I did some research, looks like HP included some Intel tool called Intel AMT or CIRA. This tool has the 192.168.1.2 hard coded into it. No where in the BIOS can I find an option to change this to either DHCP or disable it (we certainly don't want this product). Anyone know how to get rid of this?
UPDATE 2: I can't post an answer but here is the solution: Problem was caused by Intel AMT or vPro. You can disable this in the BIOS however it isn't straight forward. In the BIOS go to system configuration->AMT options. Once there turn on Verbosity Options, then you can turn on "Enable AMT unconfigure on next boot" Once you do that it clears all the AMT settings (password, et all ). You can follow this guide here http://h10032.www1.hp.com/ctg/Manual/c01954655.pdf if you want to use AMT. thanks for all your help. Also wanted to say HP support was useless they didn't even know that model had AMT nor how to disable/reset it. However after I did talk to them and bring this problem to their attention they said they would be posting a document on their website shortly.