Hi, Days ago I sent this network layout: (Internet) | (Enterprise LAN) | ||+Squid to internet and Users Auth | |+-LAN PCs | +--www Servers router | (Enterprise Substation LAN) |+Squid +-LAN PCs My doubt was if users of the Substation could be authenticated with the Enterprise's squid. Thanks to Christoph Haas by his answer. I've set on Substation's Squid this option: -------------------------------------------- cache_peer [Enterprise Squid's IP] parent 3128 0 no-query and when I try to open any web page in my browser pointing to Substation's Squid, the Enterprise's Squid send me the Auth Box but I can't authenticate myself however if I specify the Enterprise's Squid proxy on my browser, the authentication is successfully. What can be happend? Did I miss something?