Had some strange behaviour with DNS on Mac OS X earlier today. Made a change inside DNS and waited the required amount of time for the TTLs to expire. Then verified that the new IP address was resolving (using both dig and nslookup).
However, my system was still trying to use the old IP address when I tried a simple ssh or telnet command.
In the end, I discovered how to flush my local DNS cache, which fixed the problem. You can do this as follows:
$ dscacheutil -flushcache
The IPv6 debate has been rolling on now for several years with no definitive end in sight. However, for my money, the addition of several IPv6 addresses to a number of the root DNS servers earlier this week is another significant step in the right direction for IPv6.
For those of you fortunate enough not to be involved in the debate, this report by the BBC Technology website includes a simple (and brief) overview of what IPv6 is and why it is required. It’s well worth 2 minutes of your time if you have a passing interest in computing or technology generally.
Source: SlashDot
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