Folks, I have a bit problem. I enabled the authentication in the squid as bellow. However despite browser got 407 http response code, pop up window that to fill in username/password didn't show up in the browser. I also figured out that the response from the squid didn't include WWW-authenticate header. My questions are, 1 Should authenticate response from the squid include WWW-authenticate header with 407 code? 2 Did cause of acl/http_access in the squid.conf raise this problem? Here is configure options and my squid.conf. Also I'm using squid-3.HEAD. ./configure --prefix=/usr/local/squid --enable-icap-client --enable-ssl --enable-ipv6 --enable-basic-auth-helpers=NCSA --enable-auth=basic (Now ICAP has been set to OFF in the squid.conf) auth_param basic program /usr/local/squid/libexec/ncsa_auth /usr/local/squid/etc/passwd auth_param basic children 5 auth_param basic realm Squid auth_param basic credentialsttl 2 hours acl password proxy_auth REQUIRED acl localhost src 192.168.11.31/32 http_access allow localhost password --> written prior to be put "http_access deny all" Browers which I tested. IE7, Opera 9.26, Netscape7.1. Regards, SEIJI KOBAYASHI