Florin Iucha wrote:
> Guys,
> 
> I am looking in the /var/log/secure of a centos server and I see that
> the IP address is prefixed by "::ffff:".  What is that? IPv4 tunneled
> through IPv6?

Looks like an IPv4 mapped address maybe?

http://en.wikipedia.org/wiki/IPv4_mapped_address

"IPv4 mapped addresses are normally used by the IP stack to represent
IPv4 addresses to IPv6 applications."

-Steve