Updating /src from command line

[Jos Chrispijn]

I want to compile my kernel and I read that for this I need to have the 
complete /SRC tree installed.
If I do this via sysinstall, I get either a display that the chosen 
server is not available or these are not available for FreeBSD 9.
Is there a way to update /src by CVSUP or otherwise?

thanks,
Jos Chrispijn