OpenDNS can Cache a Domain for Full Time-to Live (TTL)
OpenDNS's global distribution of sophisticated DNS servers supports huge caching of DNS lookups and enables OpenDNS to store those lookups for the full Time-to-Live (TTL). OpenDNS caches are large enough to hold domains until the TTL expiration, in most cases.
TTL is set by the domain owner and tells recursive (or caching) servers how long they may cache a resolved location before asking the authoritative nameservers once again where the domain points.
However, OpenDNS also offers SmartCache that -when enabled- allows OpenDNS end-users to find websites during authoritative DNS outages. SmartCache only ignores the TTL if and when the authoritative nameserver cannot be reached.
If you are a domain owner and have recently changed your Web server addresses, you may refresh the OpenDNS caches with CacheCheck.