{"id":12,"date":"2008-08-05T16:20:49","date_gmt":"2008-08-05T16:20:49","guid":{"rendered":"http:\/\/rtechblog.psg.com\/?p=12"},"modified":"2008-08-05T21:18:57","modified_gmt":"2008-08-05T21:18:57","slug":"a-lesson-in-bgp-visibility","status":"publish","type":"post","link":"https:\/\/rtechblog.rg.net\/?p=12","title":{"rendered":"A Lesson in BGP Visibility"},"content":{"rendered":"<p>While Olaf and I were looking for other things, we stumbled on a revealing sub-experimental result.<\/p>\n<ul>\n<li>We announced a \/25 prefix via BGP from our research routers at the Westin in Seattle<\/li>\n<li>Sprint did not listen to it<\/li>\n<li>Verio\/NTT did, and said they propagated to their customers but not their peers<\/li>\n<li>We looked at BGP feeds from RouteViews, RIS, and 700+ other BGP feeds<\/li>\n<li>BGP data said the \/25 reached 15 ASs<\/li>\n<li>From a prefix in the source  \/25, we probed IP addresses in over 20,000 ASs<\/li>\n<li>1023 ASs replied<\/li>\n<li>I.e. RV et alia showed a shockingly small fraction of the real AS topology, less than 1.5%<\/li>\n<\/ul>\n<p>Interestingly, the AS path length shown in the 15 ASs visible in BGP was 3, while pingability and the BGP path length for a \/20 was the normal &gt;4.  See the <a href=\"http:\/\/www.iepg.org\/2008-07-iepg72\/bush.pdf\">diagram<\/a>.<\/p>\n<p><a href=\"http:\/\/www.iepg.org\/2008-07-iepg72\/bush.pdf\"><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>While Olaf and I were looking for other things, we stumbled on a revealing sub-experimental result. We announced a \/25 prefix via BGP from our research routers at the Westin in Seattle Sprint did not listen to it Verio\/NTT did, and said they propagated to their customers but not their peers We looked at BGP [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,9],"tags":[],"class_list":["post-12","post","type-post","status-publish","format-standard","hentry","category-measurement","category-routers"],"_links":{"self":[{"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=\/wp\/v2\/posts\/12","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12"}],"version-history":[{"count":0,"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=\/wp\/v2\/posts\/12\/revisions"}],"wp:attachment":[{"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rtechblog.rg.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}