Download nmap (nmap.org/dist/nmap-6.40-setup.exe) and do a ping scan on 192.168.1.* to see if the RPi is even on the address you are trying to ssh into (192.168.1.249). Either that or check in your router to see exactly what IP it assigned to it. It may not be the static IP you mentioned. Mine auto assigned a different IP to the RPi.
says there is an unknown OS on the ip 192.168.1.249, and my gateway is 192.168.1.1
the RPi seems to refuse SSH connection, rather than simply not being found
Did you try to use IE with 192.168.1.249
chrome and IE both fail to connect to it (but fail faster [1-2sec] than if i entered some unused ip that takes 5-10 seconds to fail the ping attempt)
Did you check anything used same ip address in you router.
ps: happened to me my playbook also used 192.168.1.249
changed the cmdline.txt file to be ip=192.168.1.240 and tried again. same result. Chrome quickly finds the device at that ip address, but returns "Oops! Google Chrome could not connect to 192.168.1.240". SSH attempts are faced with "connection refused"
what am i doing wrong? Ive wasted hours of downtime, driven myself insane, and am going to bed knowing that I won't be able to do anything until tomorrow evening at the earliest (24hrs from first plugging in my unit!) Does Punin have a different SD image i can try, maybe buzzdave's upload is no good?
When I used the cmdline.txt trick I ran a cable directly between the rpi and the laptop. Did you try that?