{"id":4293,"date":"2016-10-19T19:41:50","date_gmt":"2016-10-19T19:41:50","guid":{"rendered":"https:\/\/really.zonky.org\/?p=4293"},"modified":"2016-10-19T19:41:50","modified_gmt":"2016-10-19T19:41:50","slug":"ipv6-why-the-dns-is-so-important","status":"publish","type":"post","link":"https:\/\/really.zonky.org\/?p=4293","title":{"rendered":"IPv6: Why The DNS Is So Important"},"content":{"rendered":"

This is a bit of a thought experiment, so it may be not entirely correct (especially the maths – my probability theory is very rusty).<\/p>\n

One of the lesser reasons for using the DNS rather than IP4 addresses is that typing mistakes are more easily caught – if you intend to type 192.168.67.52, but accidentally enter 192.168.67.53 instead, you still have a valid IPv4 address. Whereas entering the domain name\u00a0wombar.example.com<\/em> instead of\u00a0wombat.example.com<\/em> will most likely get you an error instead of sending your secrets off to an unknown location on your network – unless you have a rather silly server naming convention of course!<\/p>\n

But how likely are you to make a mistake typing in an IPv4 address? According to a random web site “out there”, the average accuracy of a typist is 92%, or an\u00a0average<\/em> of 8 typos per 100 characters. If we convert this into a probability, we get a probability of typing each character correctly as 0.92.<\/p>\n

Given that typing IPv4 addresses is something that some of us have a lot of practice at, and in many cases we will notice typos before they become a problem, I’m going to arbitrarily declare that the probability of getting any character within an IPv4 address\u00a0correct<\/em> is 0.999. But to type in an IPv4 address correctly we have to get a maximum of 15 characters correct :-<\/p>\n\n\n\n\n
1<\/td>\n2<\/td>\n3<\/td>\n4<\/td>\n5<\/td>\n6<\/td>\n7<\/td>\n8<\/td>\n9<\/td>\n10<\/td>\n11<\/td>\n12<\/td>\n13<\/td>\n14<\/td>\n15<\/td>\n<\/tr>\n
1<\/td>\n9<\/td>\n2<\/td>\n.<\/td>\n1<\/td>\n6<\/td>\n8<\/td>\n.<\/td>\n1<\/td>\n2<\/td>\n8<\/td>\n.<\/td>\n1<\/td>\n2<\/td>\n8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

So the probability of getting all those characters right is 0.999 (first character) x 0.999 (second character) … Or\u00a00.999^15<\/em>.<\/p>\n

And once you work that out, subtract it from 1 (to get the probability of making a mistake) and convert it into a percentage, there is an 11% chance of making a typo in an IPv4 address.<\/p>\n

For an IPv6 address such as\u00a02001:db8:ca2c:dead:44f0:c3e9:28be:c903,\u00a0<\/em>which has 38 characters (no I’m not doing that silly table for IPv6) – 100 * (1 – 0.999 ^ 38)<\/em> – 32%.<\/p>\n

Now whilst my calculations may be a bit off, the likelihood of entering an IPv6 address incorrectly is nearly three times higher than the risk of entering an IPv4 address incorrectly.<\/p>\n

In other words, with IPv6 you\u00a0really<\/em> need a good working DNS solution just to keep the errors to manageable levels.<\/p>\n

\"dam-ip6\"<\/p>\n","protected":false},"excerpt":{"rendered":"

This is a bit of a thought experiment, so it may be not entirely correct (especially the maths – my probability theory is very rusty). One of the lesser reasons for using the DNS rather than IP4 addresses is that typing mistakes are more easily caught – if you intend to type 192.168.67.52, but accidentally […]<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"_share_on_mastodon":"0"},"categories":[4],"tags":[748,1081,1006],"class_list":["post-4293","post","type-post","status-publish","format-standard","hentry","category-it","tag-dns","tag-ipv4","tag-ipv6","category-4-id","post-seq-1","post-parity-odd","meta-position-corners","fix"],"share_on_mastodon":{"url":"","error":""},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1f2KI-17f","_links":{"self":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/4293","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4293"}],"version-history":[{"count":3,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/4293\/revisions"}],"predecessor-version":[{"id":4297,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/4293\/revisions\/4297"}],"wp:attachment":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4293"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}