Timeout waiting for ARP/RARP stack underflow

My U60 running solaris 10 crashed, and all I see on the screen is this:Timeout waiting for ARP/RARP stack underflowWhat does it mean?
[154 byte] By [etcetera] at [2007-11-26 10:26:48]
# 1
Looks like its trying to boot from the network, gets an IP address but then fails loading its kernel from tftp..Break it and try "boot disk" from the OBP. 7/M.
mAbrante at 2007-7-7 2:30:43 > top of Java-index,Solaris Operating System,Solaris 10 Features...
# 2
Why did it crash in the first place? I saw nothing in the messages log.
etcetera at 2007-7-7 2:30:43 > top of Java-index,Solaris Operating System,Solaris 10 Features...