Jmeter with Asp.Net application

I am stress testing my application using JMeter my app is made an Asp.net 4.0 app with a sql database. I am trying to achieve a full workflow from my app the current action which I am trying is for 300 users with 1 sec rampup time. I have maintained the viewstate and other required fields so that JMeter works for an Asp.net app. Most of my request are failing due to these two errors.

1.

 java.net.ConnectException: Connection timed out: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at sun.net.NetworkClient.doConnect(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.<init>(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.p开发者_C百科rotocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)

2.

HttpException (0x80004005): Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

I am just curious about these errors and want to know if this is due an application fault or are these JMeter errors?

1. Is definitely an application fault. You've ran out of connections. Work with your developer using jconsole or the like to trouble shoot server config issues. The problem may stem from the fact that you are sending 300 login requests within 1 second. The dev/test environment may simply not handle that.

2. Also looks like an application config error after doing some quick Google/Bing-ing.