Java DNS cache

Replace Java DNS with dnsjava

Prior to Java 6 DNS resolutions were cached forever.

Defaults: Java 6 DNS positive responses are cached for 30 seconds and negative responses for 10 seconds

-Dsun.net.inetaddr.ttl=3600


By default, when a security manager is installed, in order to protect against DNS spoofing attacks, the result of positive host name resolutions are cached forever. When a security manager is not installed, the default behavior is to cache entries for a finite (implementation dependent) period of time. The result of unsuccessful host name resolution is cached for a very short period of time (10 seconds) to improve performance.

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