{"id":24,"date":"2024-06-07T18:33:37","date_gmt":"2024-06-07T22:33:37","guid":{"rendered":"https:\/\/15packets.com\/?p=24"},"modified":"2024-06-08T01:53:44","modified_gmt":"2024-06-08T05:53:44","slug":"router-basics-switch-misc","status":"publish","type":"post","link":"https:\/\/15packets.com\/?p=24","title":{"rendered":"Router Basics\/Switch Misc."},"content":{"rendered":"\n<p class=\"has-medium-font-size\">ARP: Address Resolution Protocol (L2)<\/p>\n\n\n\n<p class=\"has-medium-font-size\">When sending a ping to a device connected to a switch, an ICMP (Internet Control Message Protocol) is sent to that destination IP as well as an ARP packet. This is only done when the switch does <strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">NOT<\/mark><\/strong> have the L2 MAC address stored for the destination IP address. Normally it should just send the ICMP packet. <br><br>A device will send a <mark style=\"background-color:#fcb900\" class=\"has-inline-color\"><strong>Broadcast Address<\/strong><\/mark> <strong>(FFFF.FFFF.FFFF)<\/strong> ARP packet when trying to find the MAC address associated with another device&#8217;s IP.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">When trying to connect to an IP Address outside a device&#8217;s configuration (ex. 10.1.1.0\/24 \u2192 23.93.29.392) the device will send an ARP packet to the router&#8217;s <strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">default gateway<\/mark><\/strong>. (ex. 10.1.1.5 \u2192 10.1.1.1)<\/p>\n\n\n\n<p><\/p>\n\n\n\n<div class=\"wp-block-media-text is-stacked-on-mobile\"><figure class=\"wp-block-media-text__media\"><img loading=\"lazy\" decoding=\"async\" width=\"728\" height=\"524\" src=\"https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image.png\" alt=\"\" class=\"wp-image-29 size-full\" srcset=\"https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image.png 728w, https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-300x216.png 300w\" sizes=\"auto, (max-width: 728px) 100vw, 728px\" \/><\/figure><div class=\"wp-block-media-text__content\">\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><em>An Example of this in Cisco Packet Tracer<\/em><\/p>\n<\/blockquote>\n<\/div><\/div>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-medium-font-size\">You <strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">CANNOT<\/mark><\/strong> hook up two different networks together using a switch. It will not work.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">Routers use <strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Layer 3<\/mark><\/strong> to communicate<\/p>\n\n\n\n<p class=\"has-medium-font-size\">When sending a DNS query from a device, the process of the switch, router, and device finding each other via ARP starts and a request is made. The DNS server replies with the IP information regarding the website and sends a <strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">HTTP GET<\/mark><\/strong> <em>(<strong>more on this is in later sections<\/strong>)<\/em> request to the routers default gateway and out the internet. <\/p>\n\n\n\n<p class=\"has-medium-font-size\">When looking under the hood inside a router it stores a map of all different IP networks and how it connects to all of them. This can be seen in Cisco Packet Tracer using the command <code>show ip route<\/code><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"258\" src=\"https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-1-1024x258.png\" alt=\"\" class=\"wp-image-42\" srcset=\"https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-1-1024x258.png 1024w, https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-1-300x76.png 300w, https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-1-768x194.png 768w, https:\/\/15packets.com\/wp-content\/uploads\/2024\/06\/image-1.png 1427w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>ARP: Address Resolution Protocol (L2) When sending a ping to a device connected to a switch, an ICMP (Internet Control Message Protocol) is sent to that destination IP as well as an ARP packet. This is only done when the<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-24","post","type-post","status-publish","format-standard","hentry","category-ccna"],"_links":{"self":[{"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/posts\/24","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/15packets.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=24"}],"version-history":[{"count":10,"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions"}],"predecessor-version":[{"id":44,"href":"https:\/\/15packets.com\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions\/44"}],"wp:attachment":[{"href":"https:\/\/15packets.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/15packets.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/15packets.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}