Okay.  I've apparently been using a custom version of ofwboot on  
my machine for a while.  I know I was originally trying to figure out  
how to get it to use the "filename" fed to it by dhcpd, but while I  
never got that to work, I apparently changed something else.

   I tried to update my ofwboot from the 1.10-based one I was using,  
to the current 1.12.  I couldn't boot anymore.  And, when I dropped  
back to the "unmodified" 1.10 I had on the disk, I see the same  
failure.  So, I think I'm just in "clueless user" "how do I boot my  
sparc64?" mode.  :-/

   I'm seeing:

Rebooting with command: boot net netbsd
Boot device: /sbus/SUNW,hme@e,8c00000  File and args: netbsd
Timeout waiting for ARP/RARP packet
Timeout waiting for ARP/RARP packet
Timeout waiting for ARP/RARP packet
Timeout waiting for ARP/RARP packet
 >> NetBSD/sparc64 OpenFirmware Boot, Revision 1.12
bootp: no reply
Using BOOTPARAMS protocol: ip address: 206.138.151.49bootparamd:  
'whoami' call failed
open netbsd: Unknown error: code 60
Failed to load 'netbsd'.

Boot:

   I know the initial timeouts are just based on negotiating ethernet  
parameters with the Cisco.  Typically slow.  But after that I'm  
confused that it's now working.

   Other than running bootparams, which I'd rather not do, what do I  
need to do here?  As far as I can tell, things are okay on my DHCP  
server.  It successfully booted this machine earlier this evening,  
before I foolishly overwrote my [apparently customized] ofwboot.  So,  
it's at least mostly correct.

   Thanks.  All help appreciated.

                     - Chris