Hello, Running exchnge 2007 environment with two Windows server 2003 Client Access Servers configured with Windows NLB. when I attempt to run Test-activesyncconnectivity and test-webservicesconnectivity, both fail with the following error [System.Net.WebException]: The underlying connection was closed: An unexpected error occurred on a send. Inner error [System.IO.IOException]: Authentication failed because the remote party has closed the transport stream. this error occures whether Irun the test from the CAS server itself, or from another machine. test-imap, test-pop and test-owa all work fine. I see nothing int he event logs on the CAS servers, even after upping the diagnostics logging. users are currently without issue, so I know the services are working, I am just trying to configure SCOM monitoring in troubleshooting that found out that the tests dont seem to be working. Any ideas? ChristiaanChristiaan Zaluzec

Hi, The CAS servers were setup with an NLB configuration and NLB was configured with two IP addresses. Based on my research, I found that the error message can occur if the “Default Web Site” on both CAS servers was only configured to use the first of these two IP addresses for port 443. I suggest you change the “Default Web Site” on both CAS servers to use “All Unassigned” IP addresses for port 443. After that, please run “iisreset” and check the result. Thanks. NovakPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.