I'm doing some log file analysis and need to run a reverse DNS check to ensure that I'm analysing logs from Google and not any imposters. Is there a command I can use in terminal to do this? If not, whats the best way to verify Googlebot? Thanks

Hi! I'm working on a client site at the moment and I've discovered a couple of pages that are 404ing but producing a 200 OK response. However, I have checked these URLs again and some are now producing a 404 Error response. No changes have been made (that I'm aware of) so it appears that the URLs are returning both 200 OK and 404 Error responses intermittently. Any ideas what could cause this and the best solution? Thanks!