Solaris 10 is an entirely different animal than any of the preceeding versions. So much comes pre-installed now making it a heck of a lot easier for an Admin go bounce from Linux to Solaris without having to consider what platform he/she is truly on.
One of the difficulties I recently encountered was changing the IP of an interface on Solaris 10. Now, this is usually not a difficult task, so I was surprised when a simple edit of /etc/hosts and /etc/nodename, and /etc/hostname.ipge0 didn’t have the normal impact upon rebooting.
After some digging around, it seems that Solaris 10 relies on /etc/inet/ipnodes rather than /etc/hosts. Yes, you should update both, but the important one for interface specifics is /etc/ipnodes.