{"id":3574,"date":"2019-01-08T23:39:02","date_gmt":"2019-01-09T04:39:02","guid":{"rendered":"http:\/\/toddsingleton.net\/chronicle\/?p=3574"},"modified":"2019-01-11T13:43:12","modified_gmt":"2019-01-11T18:43:12","slug":"3574","status":"publish","type":"post","link":"https:\/\/toddsingleton.net\/chronicle\/2019\/01\/08\/3574\/","title":{"rendered":"Classless networks are in style. It’s just basic subnetting."},"content":{"rendered":"

In Binary Net Masking each Octet contains exponential bits from right to left:<\/strong><\/p>\n

1\u00a0\u00a0\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1 1 1 1
\n128 64 32 16 8 4 2 1<\/span> (128+64+32+16+8+4+2+1=255<\/strong>)<\/p>\n

So..<\/strong><\/p>\n

255.255.248.0<\/span> in binary is
\n11111111. 11111111. 11111000<\/strong>. 00000000<\/strong><\/span> = \/21 (we’ll get to the identifier in a minute)<\/p>\n

255-248 = 7<\/span><\/strong>
\nTherefore 255.255.248.0 – supports 7 networks per subnet
\n255 – 248 = 7 networks<\/p>\n

Or<\/strong><\/p>\n

192.168.1.0\/21<\/strong> supports
\n192.168.1.0-255
\nthrough<\/em>
\n192.168.7.0-255<\/p>\n

The next subnet supports another 7 networks.<\/strong><\/p>\n

192.168.8.0\/21
\n192.168.8.0-255
\n through<\/em>
\n192.168.15.0-255<\/p>\n

So where does the \/21 identifier come from?<\/strong><\/p>\n

All net mask identifiers start at \/32 and go down.
\n32-21 = 11 mask bits
\nCount the zeroes in the Binary Mask!<\/strong><\/p>\n

11111111. 11111111. 11111000. 00000000<\/strong> = \/21<\/strong>
\n11111111. 11111111. 11110000. 00000000<\/strong> = \/20<\/strong> (32-20 = 12 mask bits)<\/p>\n

What’s the full net mask for the \/20 identifier above?<\/strong><\/p>\n

1\u00a0\u00a0\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1 1 1 1
\n128 64 32 16 8<\/span> 4 2 1<\/span> (8+4+2+1=15<\/strong><\/span>)<\/p>\n

\/20 = 255.255.240.0<\/strong> because <\/em>255<\/strong>–15<\/strong><\/span> = 240<\/strong><\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

In Binary Net Masking each Octet contains exponential bits from right to left: 1\u00a0\u00a0\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1\u00a0\u00a0 1 1 1 1 128 64 32 16 8 4 2 1 (128+64+32+16+8+4+2+1=255) So.. 255.255.248.0 in binary is 11111111. 11111111. 11111000. 00000000 = \/21 (we’ll get to the identifier in a minute) 255-248 = 7 Therefore 255.255.248.0 – … Continue reading Classless networks are in style. It’s just basic subnetting.<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[1,4],"tags":[],"class_list":["post-3574","post","type-post","status-publish","format-standard","hentry","category-general","category-technology"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t