We have what I think is a long running MTU problem on Rackspace hosting for a customer. We are losing parts of HTTP requests between the H5 load balancer and th

We have what I think is a long running MTU problem on Rackspace hosting for a customer. We are losing parts of HTTP requests between the H5 load balancer and the customer's web servers (which are running IIS). The header of the request reaches IIS and then the content body of the request fails to turn up causing a 500 error on the server. Issue is mostly seen on POST requests where the content of the request is going to be split over more packets. It's been driving us nuts. I wonder if we should also check the ICMP blocking too?