Hi Folks;
I'm having an issue with TMG 2010 in that I'm seeing reports of Routing/Chaining failure / TMG Detected a Loop;
Event id 14141
Forefront TMG detected a proxy server loop. There may be a problem in the configuration of the Forefront TMG Web chaining policy. Alternatively, in Enterprise Edition, when CARP is enabled and there are intermittent interruptions of intra-array connectivity, array member A may forward a request to array member B according to the CARP algorithm, and array member B may forward the request to array member A in an endless loop.
A look at the log files indicates that this error occurs when the localhost (the TMG 2010 VM itself) is connecting to Microsoft to check for Windows Updates. This is the only time the error occurs and it occurs often.
Here's a snippet to illustrate;
Microsoft-CryptoAPI/6.1 Proxy - 65.54.87.108 TCP GET Req ID: 0a655fc7; Compression: client=No, server=No, compress rate=0% decompress rate=0% - 0x110 0x0 58066 SecureNAT 1 3923 201 - 5/14/2013 1:23:26 AM - - 0 - 0 - - - - - - 0 0 From cache 65.54.87.108 5/13/2013 6:23:26 PM Local Host xx.external.IP.xx External 65.54.87.108 80 http Failed Connection Attempt - - -
[System] Allow all HTTP traffic from Forefront TMG to all networks (for CRL downloads)
12206 Forefront TMG detected a proxy chain loop. There is a problem with the configuration of the Forefront TMG routing policy. Please contact your server administrator. anonymous http://65.54.87.108/pki/mscorp/crl/mswww(6).crl EDGE Technical Information Web Proxy Filter - 0 -
Is there anyone left in the groups with knowledge of TMG 2010? I've already looked on the web for information relating to this but none seems relevant. I think the key is in the fact that it only happens when the local host goes off to Microsoft to check for Windows Updates.