{"id":751,"date":"2012-06-20T22:37:16","date_gmt":"2012-06-20T14:37:16","guid":{"rendered":"http:\/\/www.dogeye.net\/?p=751"},"modified":"2012-06-20T22:37:16","modified_gmt":"2012-06-20T14:37:16","slug":"traceroute-failed","status":"publish","type":"post","link":"https:\/\/ykyi.net\/?p=751","title":{"rendered":"traceroute failed.Specify protocal traceroute used manually to fix it."},"content":{"rendered":"<p><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \">Today, I ran the traceroute program on a machine running FreeBSD. It failed once and again.<\/span><\/span><\/p>\n<p><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \">Traceroute complained:<\/span><\/span><\/p>\n<p><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \"><span style=\"color: rgb(51, 51, 51); line-height: 19px; text-align: left; \">traceroute: sendto: Permission denied.<\/span><\/span><\/span><\/p>\n<p style=\"text-align: left;\"><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \"><font color=\"#333333\"><span style=\"line-height: 19px; \">So I tried to ping. Ping failed, too. I then checked out the configuration of the firewall, which actually denied the pass through of ICMP packet. So I set it to allow ICMP pacakges to pass through the firewall. Ping worked as I expected. But traceroute still failed.<\/span><\/font><\/span><\/span><\/p>\n<p><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \"><span style=\"line-height: 19px; color: rgb(51, 51, 51); \">I was very confused, I tried to run the tcpdump to find out why. Tcpdump showed that traceroute was sending UDP packet. Oh, my gosh. I had always thought traceroute was implemented on ICMP. After I read the tcpdump manpage. I found traceroute default on using udp protocal, but user can switch to use icmp by indicating the -M icmp or -I(The capitalized i). Alternatively, you can also command traceroute to use raw packet of specified protocol for tracerouting by specifying -P(beware P is capitalized)<\/span><span style=\"color: rgb(51, 51, 51); line-height: 19px; \">. When you use raw packet, the d<\/span>efault protocol is 253 (rfc3692).&nbsp;<span style=\"color: rgb(51, 51, 51); line-height: 19px; \">So, I ran traceroute using the command as: traceroute -P ICMP www.the_host.com, everything worked fine.<\/span><\/span><\/span><\/p>\n<p><span style=\"font-family:lucida sans unicode,lucida grande,sans-serif;\"><span style=\"font-size: 16px; \"><span style=\"color: rgb(51, 51, 51); line-height: 19px; \">COPYRIGHT WWW.DOGEYE.NET<\/span><\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Today, I ran the traceroute program on a machine running FreeBSD. It failed once and again. Traceroute complained: traceroute: sendto: Permission denied. So I tried to ping. Ping failed, too. I then checked out the configuration of the firewall, which actually denied the pass through of ICMP packet. So I set it to allow ICMP &hellip; <a href=\"https:\/\/ykyi.net\/?p=751\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;traceroute failed.Specify protocal traceroute used manually to fix it.&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,5,6,7],"tags":[59,78,80],"class_list":["post-751","post","type-post","status-publish","format-standard","hentry","category-network","category-security","category-tech_articles","category-unix_linux","tag-network-2","tag-tcpdump","tag-traceroute"],"_links":{"self":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts\/751","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=751"}],"version-history":[{"count":0,"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts\/751\/revisions"}],"wp:attachment":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=751"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=751"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=751"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}