I used to be able to use putty to connect to my pi via ssh. However, after having left it on for a while and trying to connect a couple of days later, I was faced with the message "putty fatal error: no route to host". I tried pinging my laptops ip from my pi (and vice versa) and both times the output was "destination host unreachable". I have double checked the ip addresses used using ifconfig, checked all my putty settings and checked that ssh is enabled in raspi-config, but I still cannot get a connection working. using nmap from both my laptop and my pi (laptop running ubuntu 16.04) I ran nmap scanme.nmap.org and with my public ip, and my public ip returned a message saying:
"Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn Nmap done: 1 IP address (0 hosts up) scanned in 3.13 seconds".
any help would be greatly appreciated.