mcast_miss_addr
The multicast miss stream is a largely undocumented and unsupported Squid feature. The basic idea is to send a multicast message, containing a URI, for each cache miss. The messages are encrypted with a modest algorithm to prevent casual eavesdropping.
To use this feature, you must manually define the MULTICAST_MISS_STREAM preprocessor symbol
before compiling Squid. To learn more about this feature, read the
source code surrounded by #if
MULTICAST_MISS_STREAM in src/access_log.c.