[CentOS] sorting a file

> From: Tom Brown 
> > I need to find out how many times an IP address appears in a file - the 
> > IP is the first field in the access log string so what would be the best 
> > way to sort this file and count how many times each IP address appears ?
> grep "^IP " | wc -l

Oops, replied too quickly... missed the 'each IP'
go for Stephen solution  ^_^

JD