Snooping loopback interfaces on Solaris hosts

One thing that I have always enjoyed about Linux is the ability to snoop traffic on loopback interfaces. This is extremely useful for debugging local communication problems, and the fact that you couldn’t until recently do this on Solaris hosts was extremely annoying(especially in the world of zones!). I just read Peter Memishian’s blog entry on the IP observability code that was recently putback into opensolaris, and low and behold you can now snoop loopback interfaces on Solaris hosts. This is awesome, and the ability to snoop by zone id is by far my favorite feature:

$ snoop -I bge0 zone 1

The Solaris network stack just keeps getting better and better, and with the upcoming crossbow and IPMPng putbacks just around the corner, networking in Solaris will only get better. Now if only we could get Sun to address some of the performance bugs in the networking stack!