Users are trying to access http://sms.warnerleach.co.uk which resolves to 212.50.183.91 but the page is failing with: ##### You are not authorized to view this page You do not have permission to view this directory or page using the credentials you supplied. ###### What you should get is a popup username/password box, which happens when you don't go via Squid. I've tested this on 2 different Squid servers and get the same problem. Other sites that have a popup username/password box work fine. I can't see anything in the logs that looks out of place. Below is a TCPDUMP of the request. ########################### # tcpdump -i eth0 host sms.warnerleach.co.uk tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 18:14:52.530883 IP 192.168.0.44.35562 > 212.50.183.91.http: S 1116476814:1116476814(0) win 5840 <mss 1460,sackOK,timestamp 877066833 0,nop,wscale 2> 18:14:52.537448 IP 212.50.183.91.http > 192.168.0.44.35562: S 3742409619:3742409619(0) ack 1116476815 win 17520 <mss 1460,nop,wscale 0,nop,nop,timestamp 0 0,nop,nop,sackOK> 18:14:52.537502 IP 192.168.0.44.35562 > 212.50.183.91.http: . ack 1 win 1460 <nop,nop,timestamp 877066840 0> 18:14:52.537980 IP 192.168.0.44.35562 > 212.50.183.91.http: P 1:335(334) ack 1 win 1460 <nop,nop,timestamp 877066841 0> 18:14:52.547872 IP 212.50.183.91.http > 192.168.0.44.35562: . 1:1449(1448) ack 335 win 17186 <nop,nop,timestamp 7218528 877066841> 18:14:52.547953 IP 192.168.0.44.35562 > 212.50.183.91.http: . ack 1449 win 2184 <nop,nop,timestamp 877066851 7218528> 18:14:52.547996 IP 212.50.183.91.http > 192.168.0.44.35562: . 1449:2897(1448) ack 335 win 17186 <nop,nop,timestamp 7218528 877066841> 18:14:52.548017 IP 192.168.0.44.35562 > 212.50.183.91.http: . ack 2897 win 2908 <nop,nop,timestamp 877066851 7218528> 18:14:52.548022 IP 212.50.183.91.http > 192.168.0.44.35562: . 2897:2921(24) ack 335 win 17186 <nop,nop,timestamp 7218528 877066841> 18:14:52.548035 IP 192.168.0.44.35562 > 212.50.183.91.http: . ack 2921 win 2908 <nop,nop,timestamp 877066851 7218528> 18:14:52.556413 IP 212.50.183.91.http > 192.168.0.44.35562: . 2921:4369(1448) ack 335 win 17186 <nop,nop,timestamp 7218528 877066851> 18:14:52.556438 IP 192.168.0.44.35562 > 212.50.183.91.http: . ack 4369 win 3632 <nop,nop,timestamp 877066859 7218528> 18:14:52.556443 IP 212.50.183.91.http > 192.168.0.44.35562: FP 4369:4626(257) ack 335 win 17186 <nop,nop,timestamp 7218528 877066851> 18:14:52.556707 IP 192.168.0.44.35562 > 212.50.183.91.http: F 335:335(0) ack 4627 win 3632 <nop,nop,timestamp 877066860 7218528> 18:14:52.563037 IP 212.50.183.91.http > 192.168.0.44.35562: . ack 336 win 17186 <nop,nop,timestamp 7218528 877066860> ########################### Thanks Tony -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.