HTTP 401 Response method different from one BigIP to another

Hi All,

 

I have a weird issue with APM. I have an APM policy enabled, and the first thing the policy does is a HTTP 401 Response. This policy is running on different Big-IP instances, 1 on a vCMP guest on a BigIP 5200 in one datacenter, and one another on old BigIP 3900. Both run the same BigIP version, which is 12.1.4.

 

The behavior I find strange is on my vCMP guest, the HTTP 401 Response is done through the GET method, and on my BigIP 3900, it is a POST. I found this difference while troubleshooting via Fiddler and other HTTP capture tools. Initial issue is MacOS Safari users get a weird APM error (Invalid Nonce) while trying to browse the vip hosted on vCMP. They do not get this error browsing the vip on the 3900...

 

Does anyone here has an idea what could cause this difference, and how to correct it ??

 

Thanks, /inno>