We are publishing a website through ISA to client desktop
client desktop --> ISA --> IIS servers
The whole transmission is within our company internal network, just passing through different zones.
There are 2 IIS servers, using Win2k8 NLB (network load balancing) to share a virtual IP address to receive request from ISA.
ISA is using a Website Publishing Rule to receive and redirect request.
Meanwhile, all transmission is under HTTP, it works fine.
Now we want to switch to HTTPS, so we created another Website Publishing Rule on ISA, to listen on port 443 and redirect to IIS servers' port 443.
IIS servers also opened port 443 for that same website.
Both ISA and IIS servers use the same SSL certificate to publish the website.
It seems to be working, until the load test.
We wrote a loadtest client program to generate simple requests to the servers.
Out of the thousands successful requests each day, there must be a few (less than 10) requests failed.
No error in IIS servers log. Those failed requests were successfully received and responded, with http response code 200.
But ISA log showed sc-status code 64.
ISA Diagnostic Log showed this error message: "ISA Server rejected the request with the HTTP status code 0 and will return the following error message to the Web client. "The specified network name is no longer available. (64)""
And client would receive an error html page, saying "Error Code 64: Host not available. The connection to the Web server was lost."
Googled a bit, seems to have many possible causes, including some low level problems like hardware driver bug or router, switch error.
I tried to use Microsoft Network Monitor. But honestly, I have no idea how to troubleshoot........