https://ofurotime.ca/knowledge-base/networking/Recent content in Networking on CENG Lab -- Ryo UedaHugoenSat, 06 Jun 2026 00:00:00 +0000https://ofurotime.ca/knowledge-base/networking/bgp-fundamentals/Sat, 06 Jun 2026 00:00:00 +0000https://ofurotime.ca/knowledge-base/networking/bgp-fundamentals/<h2 id="what-is-bgp" class="relative group">What is BGP? <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100"><a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700" style="text-decoration-line: none !important;" href="#what-is-bgp" aria-label="Anchor">#</a></span></h2><p>Border Gateway Protocol (BGP) is the routing protocol of the internet. It is a path-vector protocol used to exchange routing information between autonomous systems (AS).</p> <h2 id="ebgp-vs-ibgp" class="relative group">eBGP vs iBGP <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100"><a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700" style="text-decoration-line: none !important;" href="#ebgp-vs-ibgp" aria-label="Anchor">#</a></span></h2><table> <thead> <tr> <th></th> <th>eBGP</th> <th>iBGP</th> </tr> </thead> <tbody> <tr> <td>Scope</td> <td>Between different ASes</td> <td>Within the same AS</td> </tr> <tr> <td>TTL</td> <td>1 (directly connected)</td> <td>255</td> </tr> <tr> <td>Next-hop</td> <td>Changes at each hop</td> <td>Unchanged by default</td> </tr> <tr> <td>AD</td> <td>20</td> <td>200</td> </tr> </tbody> </table> <h2 id="bgp-path-selection-order" class="relative group">BGP Path Selection Order <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100"><a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700" style="text-decoration-line: none !important;" href="#bgp-path-selection-order" aria-label="Anchor">#</a></span></h2><p>BGP selects the best path using the following attributes in order:</p>