There are requests to web servers coming from 127.0.0.1 in a reverse proxy setup.
There are requests from 127.0.0.1 seen in a policy trace.
IP address 127.0.0.1 shown in access log.
There are certain features in the ProxySG that would cause requests to be coming from 127.0.0.1 (the proxy itself) as seen in the policy trace.
Cache refresh - The ProxySG will proactively refresh content of frequently accessed objects in the cache. If the refresh bandwidth configuration remains at the recommended default--Let the SG appliance manage refresh bandwidth (recommended) in the Management Console or SGOS#(config caching) refresh automatic in the CLI--then the appliance uses whatever bandwidth is available in its efforts to maintain 99.9% estimated freshness of the next access.
Pipelining - Pipelining is a feature in which the embedded objects in a container page are requested in parallel. When a user requests an html page for example, like www.aol.com, as the appliance returns the content it simultaneously requests the embedded object from the server side so that by the time the client browser requests the objects in the page, they are already in cache.
Health checks - The ProxySG performs health checks on certain configured services. For example, the ProxySG does a periodic health check to the configured DNS servers to determine if they are healthy to resolve names.
Cache refresh can be configured in the ProxySG Management Console under:
Configuration > Proxy Settings > HTTP Proxy > Freshness
Pipelining can be configured in the ProxySG Management Console under:
Configuration > Proxy Settings > HTTP Proxy > Acceleration Profile