Where is "squid_monitor_log.php" file served from?
Because if squid is configured with "Bypass proxy for Private Address destination" turned on, it should not be trying to cache when it is served from a private address space (10.x.x.x; 172.x.x.x.; 192.168.x.x ).
But it seems it is served via 215.x.x.x, and that is not private address space.
You could try and use a proxy script in the browsers. (proxy.pac or wpad.dat)
function FindProxyForURL(url, host) {
url = url.toLowerCase();
host = host.toLowerCase();
isHttp = (url.substring(0,5) == "http:");
isHttps = (url.substring(0,6) == "https:")
// If the requested website is hosted within the internal network, send direct.
if (isPlainHostName(host) ||
shExpMatch(host, "*.home") ||
shExpMatch(host, "*.local") ||
isInNet(dnsResolve(host), "10.0.0.0", "255.0.0.0") ||
isInNet(dnsResolve(host), "172.16.0.0", "255.240.0.0") ||
isInNet(dnsResolve(host), "192.168.0.0", "255.255.0.0") ||
isInNet(dnsResolve(host), "169.254.0.0", "255.255.0.0") ||
isInNet(dnsResolve(host), "127.0.0.0", "255.255.255.0"))
{ return "DIRECT"; }
// Forward non-http(s) and some hosts to forward proxy (or DIRECT)
if((!isHttp && !isHttps) // Skip all non http(s)
|| dnsDomainIs(host, "microsoft.com")
|| dnsDomainIs(host, "windowsupdate.com")
|| dnsDomainIs(host, "eset.com")
|| dnsDomainIs(host, "mcafee.com") // McAfee
|| dnsDomainIs(host, "siteadvisor.com") // McAfee
|| dnsDomainIs(host, "hackerwatch.com") // McAfee
|| dnsDomainIs(host, "hackerwatch.org") // McAfee
|| dnsDomainIs(host, "avg.com")
|| dnsDomainIs(host, "grisoft.cz")
|| dnsDomainIs(host, "avgfree.com")
|| dnsDomainIs(host, "avg.cz")
|| dnsDomainIs(host, "symantecliveupdate.com")
|| dnsDomainIs(host, "thawte.com"))
{ return "DIRECT"; }
if (isHttps)
// Skip HTTPS
{ return "DIRECT"; }
// Otherwise, go through our proxy or if it fails, through bypass
return "PROXY 192.168.0.1:3128; DIRECT";
}
