Jeez..... I should drink a coffee before responding... ouch. The syntax is correct, as you see in my post I had a typo in the verisign domain name. # ./check_http -w 5 -c 10 --ssl -H <a href="http://www.verisign.com">www.verisign.com</a> HTTP OK: HTTP/1.1 200 OK - 42718 bytes in 0.830 second response time |time=0.830120s;5.000000;10.000000;0.000000 size=42718B;;;0 So it works. Sorry for false information. Do as Bram suggested, try to "open" the website with lynx or curl. <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="gmail_quote"><div class="im"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div link="blue" vlink="purple" lang="EN-US"><div>Hello , I’m Sankar testing nagios scripts. I have tried to ping URL check from check_http script from nagios. <a href="http://nagiosplugins.org/man/check_http" target="_blank">http://nagiosplugins.org/man/check_http</a> (URL) = Reference Root# check_http -w 5 -c 10 --ssl -H <a href="http://www.verisign.com" target="_blank">www.verisign.com</a> Name or service not knownHTTP CRITICAL - Unable to open TCP socket </div></div></blockquote></div><div>You're using a wrong order... See here the difference: # ./check_http -w 5 -c 10 --ssl -H <a href="http://www.verisisgn.com" target="_blank">www.verisisgn.com</a><div class="im"> Name or service not known HTTP CRITICAL - Unable to open TCP socket </div># ./check_http -H <a href="http://www.verisign.com" target="_blank">www.verisign.com</a> --ssl -w 5 -c 10 HTTP OK: HTTP/1.1 200 OK - 42718 bytes in 0.822 second response time |time=0.821882s;5.000000;10.000000;0.000000 size=42718B;;;0 I know the way you tried it is shown in the --help but it obviously doesn't work. </div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="im"><div link="blue" vlink="purple" lang="EN-US"><div> Please help us in checking whether URL is up or down. How efficiently this script can be used ?Is there any way to find out URL availability ? with port ? or ping ? can we pass proxy ? Thanks in advance. Best regards, Sankar </div></div> </div><div class="im"> ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. <a href="http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/" target="_blank">http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/</a> _______________________________________________ Nagios-users mailing list <a href="mailto:Nagios-users@lists.sourceforge.net" target="_blank">Nagios-users@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/nagios-users" target="_blank">https://lists.sourceforge.net/lists/listinfo/nagios-users</a> ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null </div></blockquote></div> </blockquote></div>