{"id":235,"date":"2017-09-21T11:22:46","date_gmt":"2017-09-21T09:22:46","guid":{"rendered":"http:\/\/www.quisted.net\/?p=235"},"modified":"2017-09-21T11:22:46","modified_gmt":"2017-09-21T09:22:46","slug":"ibgp-ebgp","status":"publish","type":"post","link":"https:\/\/www.quisted.net\/index.php\/2017\/09\/21\/ibgp-ebgp\/","title":{"rendered":"iBGP &#8211; eBGP"},"content":{"rendered":"<p>&nbsp;<\/p>\n\n<table id=\"tablepress-1\" class=\"tablepress tablepress-id-1\">\n<thead>\n<tr class=\"row-1\">\n\t<td class=\"column-1\"><\/td><th class=\"column-2\">eBGP<\/th><th class=\"column-3\">iBGP<\/th>\n<\/tr>\n<\/thead>\n<tbody class=\"row-striping row-hover\">\n<tr class=\"row-2\">\n\t<td class=\"column-1\"><\/td><td class=\"column-2\">External BGP<\/td><td class=\"column-3\">Internal BGP<\/td>\n<\/tr>\n<tr class=\"row-3\">\n\t<td class=\"column-1\">Neighbor<\/td><td class=\"column-2\">Between differnet AS<\/td><td class=\"column-3\">Within the same AS<\/td>\n<\/tr>\n<tr class=\"row-4\">\n\t<td class=\"column-1\">Route updates<\/td><td class=\"column-2\">Routes are send to eBGP peers by default<\/td><td class=\"column-3\">Routes are not send to BGP peers by default<\/td>\n<\/tr>\n<tr class=\"row-5\">\n\t<td class=\"column-1\">AS path addition<\/td><td class=\"column-2\">yes<\/td><td class=\"column-3\">no<\/td>\n<\/tr>\n<tr class=\"row-6\">\n\t<td class=\"column-1\">Administrative distance<\/td><td class=\"column-2\">20<\/td><td class=\"column-3\">200<\/td>\n<\/tr>\n<tr class=\"row-7\">\n\t<td class=\"column-1\">Topology<\/td><td class=\"column-2\">Does not require a full mesh<\/td><td class=\"column-3\">Full mesh or Route reflectors or Confedoration<\/td>\n<\/tr>\n<tr class=\"row-8\">\n\t<td class=\"column-1\">Loop Prevention<\/td><td class=\"column-2\">as-path<\/td><td class=\"column-3\">BGP split horizon<\/td>\n<\/tr>\n<tr class=\"row-9\">\n\t<td class=\"column-1\"><\/td><td class=\"column-2\"><\/td><td class=\"column-3\"><\/td>\n<\/tr>\n<tr class=\"row-10\">\n\t<td class=\"column-1\"><\/td><td class=\"column-2\"><\/td><td class=\"column-3\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-1 from cache -->\n<p><!--more--><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.quisted.net\/index.php\/2017\/09\/21\/ibgp-ebgp\/#eBGP\" >eBGP<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.quisted.net\/index.php\/2017\/09\/21\/ibgp-ebgp\/#eBGP_neighborship_requirements\" >eBGP neighborship requirements<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.quisted.net\/index.php\/2017\/09\/21\/ibgp-ebgp\/#iBGP_neighborship_requirements\" >iBGP neighborship requirements<\/a><\/li><\/ul><\/nav><\/div>\n<h3><span class=\"ez-toc-section\" id=\"eBGP\"><\/span><strong>eBGP<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li>3 steps to get best routes;\n<ul>\n<li>Form a neighbor relationship.\n<ul>\n<li><em>router bgp<\/em> <strong><span style=\"color: #ff6600;\">1000<\/span><\/strong><\/li>\n<li><em>neighbor<\/em> <strong><span style=\"color: #339966;\">10.10.10.10<\/span><\/strong> <em>remote-as <\/em><strong><span style=\"color: #3366ff;\">2000<\/span><\/strong><\/li>\n<\/ul>\n<\/li>\n<li>Exchange topology information.<\/li>\n<li>Run a best-path algorithm<\/li>\n<\/ul>\n<\/li>\n<li>Assumed to be directly connected (apart from multihop)<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"eBGP_neighborship_requirements\"><\/span>eBGP neighborship requirements<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li>Peer must be reachable via an IGP route.<\/li>\n<li>BGP router IDs cannot be the same.<\/li>\n<li>Authentication must match.<\/li>\n<li>Router must complete a TCP connection (tcp 3 way handshake) with the BGP peer.<\/li>\n<li>Source adress must match the other side&#8217;s BGP neighbor command.<\/li>\n<\/ul>\n<pre>R1#(config)router bgp <strong><span style=\"color: #3366ff;\">10<\/span><\/strong>\nR1#(config-router)neighbor 20.20.20.20 remote-as <strong><span style=\"color: #ff6600;\">20<\/span><\/strong>\n\nR2#(config)router bgp <span style=\"color: #ff6600;\"><strong>20<\/strong><\/span>\nR2#(config-router)neighbor 10.10.10.10 remote-as <span style=\"color: #3366ff;\"><strong>10\n<\/strong><\/span><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"iBGP_neighborship_requirements\"><\/span>iBGP neighborship requirements<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li>Must be in the same AS as the iBGP peer.<\/li>\n<li><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[12,8],"tags":[],"class_list":["post-235","post","type-post","status-publish","format-standard","hentry","category-bgp","category-route"],"_links":{"self":[{"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/posts\/235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/comments?post=235"}],"version-history":[{"count":0,"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/posts\/235\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/media?parent=235"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/categories?post=235"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.quisted.net\/index.php\/wp-json\/wp\/v2\/tags?post=235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}