amazon web services - my EC2 instance seems down and it won't reboot from the console -

i have ec2 instance running on ubuntu 14.04 that's been 3 months. got ip address whitelisted payment processing partner it's kind of hard decision reboot since ip address going change. here's has happened : working on via ssh, launching node.js process , watching logs using mobile app communicating it, of sudden stopped responding keyboard input. can't visit website hosted on , can't ssh in :

ssh: connect host ***.***.***.*** port 22: can't assign requested address 

and can't reboot instance console : click reboot, alert dialog click "yes sure", nothing happens, instance still running after refreshing page , same ip address.

what should ?

sometimes ec2s crash , can take hours respond reboot console. in rare cases amazon has involved kill it. best thing take snapshot of attached storage , create new ec2 instance.

with regards ip should using elastic ip. 1 free 1 per ec2 , it's yours keep till release it. if have 1 can recreate ec2 snapshots , attach elastic ip , , running in minutes.

edit

as example ec2 crashed around 2 months ago same problem. recreated snapshots , moved elastic ip. after 4-6 hours ec2 stopped , start again have read in forums aws needs involved.