- You have a downstream proxy that has Microsoft Forefront Threat Management Gateway (TMG) 2010 installed.
- You configure network traffic interoperability between the downstream proxy and an upstream proxy.
- A client computer tries to create a Secure Hypertext Transfer Protocol (HTTPS) connection through the downstream and upstream proxies to a web server.
- HTTP/1.1 502 Proxy Error (Arithmetic result exceeded 32 bits.)
- HTTP/1.1 502 Proxy Error (-2147471495) ERROR_HTTP_INVALID_HEADER
When you try to create a HTTPS connection, the downstream proxy that has Forefront TMG 2010 installed forwards the HTTPS CONNECT request to the upstream proxy. The upstream proxy returns a response packet that has some additional headers. However, Forefront TMG 2010 cannot parse the response if the returned packet is split into multiple packets.
Update informationTo resolve this issue, install the software update that is described in the following Microsoft Knowledge Base (KB) article:
Article ID: 2445662 - Last Review: Nov 17, 2010 - Revision: 1