WCF Error with TCP - wcf

Question

I have a website which connects to a WCF service deployed in IIS on two application servers behind a load balancer & firewall. When I use HTTP endpoints the website is able to connect to the WCF service successfully. However on switching to TCP protocol, I am seeing the following error.
More data was expected, but EOF was reached.
[InvalidDataException: More data was expected, but EOF was reached.]
[ProtocolException: Error while reading message framing format at position 0 of stream (state: ReadingUpgradeRecord)]
[ProtocolException: The server at net.tcp:///SecurityService.svc rejected the session-establishment request.]
The website application pool is running under a local user account, while the WCF services are running under default ApplicationPoolIdentity. No trace logs are getting generated at the service end. Trace logs are getting generated at the client end with the same error.
The WCF service is hosted under the default port 808 in the application server, but it is not being shared by any other application/service.
Environment: Win2k8, IIS 7.5
I have verified the TCP connectivity to the application server from the web server and it is fine.
Please let me know if any other information is needed from my side. Really appreciate any guidance as I have spent a lot of time on this.
The snippet from the config files are below:
WCF Service
<bindings>
<netTcpBinding>
<binding name="NetTcpBinding_Configuration" closeTimeout="00:10:00"
openTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:10:00"
transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions"
hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="524288"
maxBufferSize="2147483647" maxConnections="100" maxReceivedMessageSize="2147483647">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:10:00"
enabled="false" />
<security mode="None"/>
</binding>
</netTcpBinding>
</bindings>
<services>
<service name="<namespace>.ServiceImplementation.Security">
<endpoint address="net.tcp://<servername>/SecurityService.svc"
binding="netTcpBinding" bindingConfiguration="NetTcpBinding_Configuration"
contract="<namespace>.ServiceInterface.ServiceContracts.ISecurity" name="NetTcpBinding_Security">
<identity>
<servicePrincipalName value="host/<servername>" />
</identity>
</endpoint>
</service>
</services>
Website Client
<bindings>
<basicHttpBinding>
<binding name="BasicHttpBinding_Configuration" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="2147483647" maxBufferPoolSize="524288" maxReceivedMessageSize="2147483647" messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered" useDefaultWebProxy="true">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<security mode="None">
<transport clientCredentialType="None" proxyCredentialType="None" realm="" />
<message clientCredentialType="UserName" algorithmSuite="Default" />
</security>
</binding>
</basicHttpBinding>
<netTcpBinding>
<binding name="NetTcpBinding_Configuration" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions" hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="524288" maxBufferSize="2147483647" maxConnections="10" maxReceivedMessageSize="2147483647">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" />
<security mode="None" />
</binding>
</netTcpBinding>
</bindings>
<client>
<endpoint address="http://<servername>/SecurityService.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_Configuration" contract="SecurityService.Security" name="BasicHttpBinding_Security" />
<endpoint address="net.tcp://<servername>/SecurityService.svc" binding="netTcpBinding" bindingConfiguration="NetTcpBinding_Configuration" contract="SecurityService.Security" name="NetTcpBinding_Security">
<identity>
<servicePrincipalName value="host/<servername>" />
</identity>
</endpoint>
</client>

Answer 1

If I was you, I would Wireshark the traffic going from the client to the server. You just want to make sure that your traffic is not getting blocked somewhere along the way. If you can confirm that this is NOT the case, then it has to be a WCF service configuration issue.
Before you attempt to debug WCF config, try to remove the load balancer out of the picture(if you can), and hit the WCF service directly. Most of the load balancers will support HTTP by default; but will need special configuration for any other protocols.