Hi,

So we're struggling with IE and its caching mechanism in our active active data centre testing platform.

It would appear as though (not sure since which browser version) that IE11 has a 30 minute cache feature that holds the original destination public IP address in memory.

Now during a successful connection to www.testing123.com (test domain) - data centre A the client test machine pulls the A record from the GSS with a TTL of 120 - all good there. Now when we simulate a failure at data centre A at www.testing123.com DNS goes back to the GSS and requests the same record but the GSS responds with data centre B - we can verify this with ping and looking at the local DNS cache - all good there. Now hitting F5 at the IE11 browser the page does not swing over to the new data centre it remains stuck to data centre A. The only way for force the session over to data centre B (based around the new local DNS cache) is to restart the browser or clear the browser cache.

Anyone come across this before? In google chrome the issue doesn't exist an F5 request in the browsers forces the browser to go and check its local DNS cache and for that reason the web sites swings round to the other DC successfully.

Anyone got any recommendations? Is there something within IIS that we can enable to force the local lookup without affecting the end user experience?

Cheers