Hello, the router from ISP has IPv6 disabled; my public IP is only IPv4; I get regularily a message like this: ERROR The requested URL could not be retrieved ------------------------------------------------------------------------ While trying to retrieve the URL:http://www.google.com/firefox? <http://www.google.de/firefox?> The following error was encountered: * *Connection to 2a00:1450:4001:80b::1017 Failed * The system returned: /(101) Network is unreachable/ The remote host or network may be down. Please try the request again. Your cache administrator is my-email. ------------------------------------------------------------------------ Generated Fri, 28 Feb 2014 13:03:40 GMT by myproxy-host (squid/3.3.11) my squid is running on CentOS 6.5 64-bit; I already have the following in squid.conf tcp_outgoing_address myproxy-host's IPv4-address all and dns_v4_first on Thanks for help, Walter