"Knife ec2 server creates" fails

knife ec2 server create -d ubuntu -f m1.large -i ami-cef405a7
  [WARN] Fog::AWS::Compute.new is deprecated, use Fog::Compute.new(:provider => 'AWS') instead (/mnt/gems-chef-0.5/gems/fog-0.7.2/lib/fog/core/service.rb:58:in `new') 
Instance ID: i-aafeefc5
Flavor: m1.large
Image: ami-cef405a7
Availability Zone: us-east-1b
Security Groups: default
SSH Key: 

Waiting for server...............
Public DNS Name: ec2-50-17-47-236.compute-1.amazonaws.com
  [WARN] Fog::AWS::Compute::Server => #ip_address is deprecated, use #public_ip_address instead (/mnt/gems-chef-0.5/gems/fog-0.7.2/lib/fog/compute/models/aws/server.rb:9)
Public IP Address: 50.17.47.236
Private DNS Name: domU-12-31-39-0E-BA-12.compute-1.internal
Private IP Address: 10.192.185.220

Waiting for sshd/mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/knife/ec2_server_create.rb:121:in `initialize': No route to host - connect(2) (Errno::EHOSTUNREACH)
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/knife/ec2_server_create.rb:121:in `new'
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/knife/ec2_server_create.rb:121:in `tcp_test_ssh'
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/knife/ec2_server_create.rb:183:in `run'
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/knife.rb:131:in `run'
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/lib/chef/application/knife.rb:120:in `run'
	from /mnt/gems-chef-0.5/gems/chef-0.9.16/bin/knife:25
	from /mnt/gems-chef-0.5/bin/knife:19:in `load'
	from /mnt/gems-chef-0.5/bin/knife:19