Everyone keeps getting kicked and getting tis messsage...

Everyone keeps getting kicked and here is some of the messages.
Bukkit Ver: 16:16:52 [INFO] This server is running Craftbukkit version git-Bukkit-0.0.0-1131-g86b7fa8-b1337jnks (MC: 1.8.1)
16:16:52 [INFO] This server is also sporting some funky dev build of Bukkit!
OS Version: CentOS

Code:

16:14:50 [INFO] Disconnecting TheFarshooter [/92.21.84.255:10444]: Failed to verify username! [internal error java.net.UnknownHostException: session.minecraft.net]
16:14:50 [SEVERE] java.net.UnknownHostException: session.minecraft.net
16:14:50 [SEVERE]       at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
16:14:50 [SEVERE]       at java.net.SocksSocketImpl.connect(Unknown Source)
16:14:50 [SEVERE]       at java.net.Socket.connect(Unknown Source)
16:14:50 [SEVERE]       at java.net.Socket.connect(Unknown Source)
16:14:50 [SEVERE]       at sun.net.NetworkClient.doConnect(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.http.HttpClient.openServer(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.http.HttpClient.openServer(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.http.HttpClient.<init>(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.http.HttpClient.New(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.http.HttpClient.New(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
16:14:50 [SEVERE]       at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
16:14:50 [SEVERE]       at java.net.URL.openStream(Unknown Source)
16:14:50 [SEVERE]       at net.minecraft.server.ThreadLoginVerifier.run(ThreadLoginVerifier.java:34)
16:15:02 [INFO] Lemonade1947 [/77.103.204.48:55733] logged in with entity id 32101 at ([world2] 345.28125, 78.0, 261.40625)
16:15:06 [INFO] darenboi34 lost connection: user was kicked.
16:15:06 [INFO] darenboi34 [/92.233.78.220:52799] logged in with entity id 32143 at ([world2] 337.28125, 72.0, 253.28125)
16:15:08 [SEVERE] java.net.SocketException: Socket closed
16:15:08 [SEVERE]       at java.net.SocketOutputStream.socketWrite(Unknown Source)
16:15:08 [SEVERE]       at java.net.SocketOutputStream.write(Unknown Source)
16:15:08 [SEVERE]       at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
16:15:08 [SEVERE]       at java.io.BufferedOutputStream.flush(Unknown Source)
16:15:08 [SEVERE]       at java.io.DataOutputStream.flush(Unknown Source)
16:15:08 [SEVERE]       at net.minecraft.server.NetworkWriterThread.run(SourceFile:104)
16:15:08 [INFO] Connection reset

 

I get the "java.net.UnknownHostException: session.minecraft.net" message whenever I try to log in to server with bukkit. It only started a few minutes ago, and I don't know what is going on.

 

Minecraft.net may be down; Try it with the server property "online-mode" set to false. You should also check to see if other servers are having the same problem when trying to log in.

 

What was the last time you downloaded a plugin ? and since when did you get the message?

 

I think I might know whats causeing this problem it might got something to do with the static ip configuration