{"version":"1.0","provider_name":"Infoblox Blog","provider_url":"https:\/\/www.infoblox.com\/blog","author_name":"Ed Horley","author_url":"https:\/\/www.infoblox.com\/blog\/author\/ed-horley\/","title":"ULA is Broken (in Dual-stack Networks)","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"JhOmorOty3\"><a href=\"https:\/\/www.infoblox.com\/blog\/ipv6-coe\/ula-is-broken-in-dual-stack-networks\/\">ULA is Broken (in Dual-stack Networks)<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.infoblox.com\/blog\/ipv6-coe\/ula-is-broken-in-dual-stack-networks\/embed\/#?secret=JhOmorOty3\" width=\"600\" height=\"338\" title=\"&#8220;ULA is Broken (in Dual-stack Networks)&#8221; &#8212; Infoblox Blog\" data-secret=\"JhOmorOty3\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/* <![CDATA[ *\/\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/* ]]> *\/\n<\/script>\n","thumbnail_url":"https:\/\/www.infoblox.com\/blog\/wp-content\/uploads\/479422010-660x454-2.jpg","thumbnail_width":660,"thumbnail_height":454,"description":"ULA is Broken (in Dual-stack Networks). I first started outlining some of the difficulties with Unique Local Addresses (ULA, RFC 4193) in the blog post \u201cIPv6 ULA and NAT. Is It Better Than Global Unicast?\u201d back in January of 2014. First: Why you shouldn\u2019t reflexively deploy ULAs and NAT66Second: How failing to randomize ULA prefixes could cause problems (and cause you to end up DEAD:BEEF!)Third: Understanding the differences between fc00::\/7 vs. fc00::\/8 vs. fd00::\/8"}