{"id":595,"date":"2020-11-12T20:12:57","date_gmt":"2020-11-12T20:12:57","guid":{"rendered":"https:\/\/dft.wiki\/?p=595"},"modified":"2026-06-09T13:29:13","modified_gmt":"2026-06-09T17:29:13","slug":"ebgp-routing-protocol-with-cisco-devices","status":"publish","type":"post","link":"https:\/\/dft.wiki\/?p=595","title":{"rendered":"eBGP Routing Protocol on Cisco Devices"},"content":{"rendered":"<p>BGP (Border Gateway Protocol) is the routing protocol of the Internet, and due to the size of the global network, it is also the slowest.<\/p>\n<p>It does not see each individual router on the Internet, but it knows how to reach autonomous systems, which are large network pools. Internet service providers are autonomous systems, and large companies like Microsoft and Google are as well.<\/p>\n<p>This post is for reference only and assumes the ISP configuration below, which runs BGP and connects the edge router to this BGP network:<\/p>\n<pre>hostname ISP\r\nno ip domain-lookup\r\ninterface L0\r\nip address <strong>10.10.10.10<\/strong> 255.255.255.255\r\ninterface Serial0\/0\/1\r\nip address <strong>200.200.200.1<\/strong> 255.255.255.252\r\nno shut\r\nip route 0.0.0.0 0.0.0.0 l0\r\nrouter bgp 65001\r\nbgp log-neighbor-changes\r\nnetwork 0.0.0.0\r\nneighbor <strong>200.200.200.2<\/strong> remote-as 65000\r\nend<\/pre>\n<p>Note: <strong>10.10.10.10<\/strong> simulates the Internet on the ISP side, <strong>200.200.200.1<\/strong> is the ISP router&#8217;s address, and <strong>200.200.200.2<\/strong> is the address of your network connected to the ISP (meaning the ISP router must be configured to exchange routing information with your network).<\/p>\n<p>Join your router to the ISP BGP network:<\/p>\n<pre>router bgp 65000\r\nneighbor <strong>200.200.200.1<\/strong> remote-as 65001\r\nnetwork <strong>200.100.100.0<\/strong> mask 255.255.255.0<\/pre>\n<p>Note: <strong>200.200.200.1<\/strong> is the ISP address and <strong>200.100.100.0<\/strong> is the internal network you will advertise on the Internet through the ISP router.<\/p>\n<p>Useful commands for troubleshooting:<\/p>\n<pre>show ip route\r\nshow ip bgp\r\nshow ip bgp summary<\/pre>\n<p>This post is a quick reference guide for commands, based on Cisco Lab 3.5.3.5. Consider looking up the source material for more detailed information.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>BGP (Border Gateway Protocol) is the routing protocol of the Internet, and due to the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-595","post","type-post","status-publish","format-standard","hentry","category-ccna"],"_links":{"self":[{"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/posts\/595","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dft.wiki\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=595"}],"version-history":[{"count":5,"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/posts\/595\/revisions"}],"predecessor-version":[{"id":5812,"href":"https:\/\/dft.wiki\/index.php?rest_route=\/wp\/v2\/posts\/595\/revisions\/5812"}],"wp:attachment":[{"href":"https:\/\/dft.wiki\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=595"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dft.wiki\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=595"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dft.wiki\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=595"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}