Detecting presence (or absence) of IPv6 on WAN interfaces

[Philip Prindeville]

Hi all,

Is there some state available in init.d scripts for detecting if we have IPv6 on the publicly facing Internet?  Or do I have to read the network config, look for wan* interfaces, and see if any of them have IPv6 addresses configured, etc?

Was hoping that this was already neatly done with a ribbon on it...

"Why?" might you ask?  Because some services (Bind in particular) generates a slew of logging noise when you try to query an AAA record, but it only has IPv4 connectivity to the internet.  It really doesn't like that, so detecting the absence of IPv6 and starting it with "-4" really seems to quiet it down a lot.

Thanks,

-Philip