NFS Timeout or crash?

Is it possible for a router to flood a machine during an NFS client to
server transaction and cause the server to freeze? I am asking because
my NFS server on Gentoo Linux used to freeze during a huge file copy
over my 10/100 network but once I reinstalled the firmware on my
router, it got much better and not any more freezes. Could it be
because I was playing with ping -f on my own network to see what would
happen to my machines if they were ping flooded?