Site Failure - GTM/LTM

bookmarking a page saves the name, not the ip, so that shouldn't be a problem. You have system cache, which most current OS's honor TTL, then you have browser caches, none of which honor TTL (last I checked, IE through 7 cached for 30 minutes, FF for 1 minute, not sure on Chrome)

 

 

Setting lower ensures a faster failover at the ldns layer, but also increases traffic handling requirements (ex, if you set at 5 minutes versus the 30 sec default, you decrease the poll interval by 10x).