A major DDoS attack hit Netlify's main load balancer in Chicago, but most sites remained unaffected due to their DNS setup. The issue was caused by using the root domain (e.g., `example.com`) instead of prefixing with `www`. This can lead to severe consequences, including breaking email and validation records. To mitigate this, Netlify recommends using a CNAME record pointing at `<yoursite>.netlify.com`, which allows for traffic direction around outages. However, using the root domain alone can cause issues, as it prevents DNS hosts from setting other records, such as A or AAAA records, on the apex domain. Some DNS hosts offer workarounds, like ALIAS records, to solve these limitations, but may impact precision in geographic lookups. The ideal setup is to use a canonical domain with a subdomain (e.g., `www.example.com`) and a DNS host that supports CNAME on the apex domain.