I have hit a wall with regard to this issue and I have no inkling whatsoever as to what might have happened. Any help regarding this matter will be greatly appreciated.
I connect to my Raspberry Pi 2 over the network, SSH-ing into it. Today, I tried upgrading the from the wheezy version to Jessie by changing the /etc/apt/sources.list file and using apt-get dist-upgrade. Installation finished normally, with no exceptions. I restarted the Pi and now I can't seem to SSH into it anymore. Trying to ping it returns a request timeout message. I don't have a display to connect my raspberry pi to, so I don't have anymore information to give regarding this issue, only that I can't even ping it anymore! I apologize for the clueless nature of the post, but I really can't think of where to even begin troubleshooting.