{"id":2987,"date":"2011-06-16T20:23:38","date_gmt":"2011-06-17T02:23:38","guid":{"rendered":"http:\/\/gregsowell.com\/?p=2987"},"modified":"2011-06-16T20:23:38","modified_gmt":"2011-06-17T02:23:38","slug":"is-arp-considered-layer2-or-layer3","status":"publish","type":"post","link":"https:\/\/gregsowell.com\/?p=2987","title":{"rendered":"Is ARP Considered Layer2 Or Layer3"},"content":{"rendered":"<p>I was discussing an issue with a customer the other day when he told me that layer3 was working because ARP was functioning.  I told him that ARP is a layer 2 service that assists layer 3.  He told me &#8220;you are wrong, but whatever.&#8221;  \ud83d\ude42  I didn&#8217;t argue.  This customer is always abrupt and abrasive.  I don&#8217;t blame them&#8230;I think past bad experiences trained them to approach their providers like this.  I forgive you&#8230;hehehe<\/p>\n<p>What is the function of <a href=\"http:\/\/en.wikipedia.org\/wiki\/Address_Resolution_Protocol\">ARP<\/a>?  ARP takes an IP address and resolves this to a layer 2 MAC address.<\/p>\n<p>The answer to the question above is&#8230;both&#8230;sort of.  <\/p>\n<p>It is technically encapsulated by the link layer protocol and is required only to facilitate the operation of L3 which causes some to argue that is L3.  <\/p>\n<p>However, ARP packets are <strong>not routable<\/strong> nor do they have IP headers.  ARP is a broadcast frame that is sent on a layer 2 segment.  ARP has no protocol number and has type = 0x806.  Which all lends itself to L2.<\/p>\n<p>Ultimately ARP operates only at L2 but &#8220;provides services&#8221; to L3.  What does this really mean&#8230;that it just plain works.  It will continue to work and the world will continue to turn.  What are your opinions?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I was discussing an issue with a customer the other day when he told me that layer3 was working because ARP was functioning. I\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-2987","post","type-post","status-publish","format-standard","hentry","category-networking"],"_links":{"self":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/2987","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2987"}],"version-history":[{"count":9,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/2987\/revisions"}],"predecessor-version":[{"id":2996,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/2987\/revisions\/2996"}],"wp:attachment":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2987"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2987"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}