diff --git a/lib/fog/aws.rb b/lib/fog/aws.rb
index daf8509e2..5ed2c283b 100644
--- a/lib/fog/aws.rb
+++ b/lib/fog/aws.rb
@@ -186,6 +186,10 @@ module Fog
         ip.join('.')
       end
 
+      def self.private_ip_address
+        ip_address.gsub(/^\d{1,3}\./,"10.")
+      end
+
       def self.kernel_id
         "aki-#{Fog::Mock.random_hex(8)}"
       end
diff --git a/lib/fog/aws/requests/compute/describe_instances.rb b/lib/fog/aws/requests/compute/describe_instances.rb
index 652066d7b..e47a3f1d0 100644
--- a/lib/fog/aws/requests/compute/describe_instances.rb
+++ b/lib/fog/aws/requests/compute/describe_instances.rb
@@ -179,7 +179,7 @@ module Fog
                 instance['ipAddress']         = Fog::AWS::Mock.ip_address
                 instance['originalIpAddress'] = instance['ipAddress']
                 instance['dnsName']           = Fog::AWS::Mock.dns_name_for(instance['ipAddress'])
-                instance['privateIpAddress']  = Fog::AWS::Mock.ip_address
+                instance['privateIpAddress']  = Fog::AWS::Mock.private_ip_address
                 instance['privateDnsName']    = Fog::AWS::Mock.private_dns_name_for(instance['privateIpAddress'])
                 instance['instanceState']     = { 'code' => 16, 'name' => 'running' }
               end
diff --git a/lib/fog/aws/requests/compute/start_instances.rb b/lib/fog/aws/requests/compute/start_instances.rb
index 102f6ea3d..d7765687c 100644
--- a/lib/fog/aws/requests/compute/start_instances.rb
+++ b/lib/fog/aws/requests/compute/start_instances.rb
@@ -34,6 +34,7 @@ module Fog
 
           instance_set = self.data[:instances].values
           instance_set = apply_tag_filters(instance_set, {'instance_id' => instance_ids}, 'instanceId')
+          instance_set = instance_set.find_all {|x| instance_ids.include?(x["instanceId"]) }
 
           if instance_set.empty?
             raise Fog::Compute::AWS::NotFound.new("The instance ID '#{instance_ids.first}' does not exist")
diff --git a/lib/fog/aws/requests/compute/stop_instances.rb b/lib/fog/aws/requests/compute/stop_instances.rb
index a7b719799..3a54dad07 100644
--- a/lib/fog/aws/requests/compute/stop_instances.rb
+++ b/lib/fog/aws/requests/compute/stop_instances.rb
@@ -35,6 +35,7 @@ module Fog
 
           instance_set = self.data[:instances].values
           instance_set = apply_tag_filters(instance_set, {'instance_id' => instance_ids}, 'instanceId')
+          instance_set = instance_set.find_all {|x| instance_ids.include?(x["instanceId"]) }
 
           if instance_set.empty?
             raise Fog::Compute::AWS::NotFound.new("The instance ID '#{instance_ids.first}' does not exist")