Dedicated server - Can't reach auth servers

I am having Ubuntu server 15.10 with Multicraft.
When I make an server, and try to join I get following error;
"ERROR Couldn't verify username because servers are unavailable"

Java version:

Code (Text):

openjdk version "1.8.0_66-internal"
OpenJDK Runtime Environment (build 1.8.0_66-internal-b17)
OpenJDK 64-Bit Server VM (build 25.66-b17, mixed mode)
 

IPTables:

Code (Text):

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
 

[FIXED] Fixed it myself;
If anyone ever stumbles upon this, you are most probably using openjdk java version, delete openjdk version of java and install Oracle JRE version. Google should help you with that

 

If you would put an actual effort in reading what I wrote you could see I fixed it myself