>I'm trying to boot a Personal Decstation 5000/33
>from a Decsystem 5100 running Ultrix 4.3.
>
>On the 5100 i have the following /etc/bootptab:
># host          htype haddr             iaddr           bootfile
>#
[snip]

>cherry          1 08:00:2b:33:7c:a8     192.168.10.4    nfsnetbsd

I hope nfsnetbsd is the ECOFF-format file.   The ecoff-format
file is usually called "nfsnetbsd.ecoff", so I suspect it isn't.
The DECstation PROMs can only netboot ECOFF-format files.
Might that be your problem?

Otherwise it looks OK.  Could you double-check you have the ECOFF
file?  If you do,, you may well have one of the PROM versions that
fails to boot successfully using bootp/tftp.  If so, the best
alternative is to use mop: Try adding a mop host on the Decsystem
5100, using "addnode".   I think something like

    addnode -n CHERRY -h 08:00:2b:33:7c:a8  -l /var/tftp/nfsnetbsd.ecoff

is  close to correct. (See man 8 addnode first, it's unforgiving).

>Can you see a big mistake in my setup, or do
>i need to start some other daemons ?
>If anyone managed to get a Decstation to boot
>from an Ultrix or Linux server, maybe he/she can tell me some
>details.

I'm not a Linux bootpd wizard, but it sounds like the LInux bootpd
response isn't getting to the Personal Decstation.  Can you use
tcpdump on a third box to verify that the bootp response is being sent
out properly?  Without that, it's hard to be sure.

It looks kind of suspicious that the LInux bootpd says it got a packet
from a given IP address, rather than a given Ethernet MAC address.  I
don't _think_ the DECstation PROM is holding onto the IP address and
putting it in the bootp request i; but if *it* did, it's very unlikley
the DEC box will answer ARP requests.  Tcpdump (or equivalent)
trace of all packets to or from the DECstatio really is the best
diagnostic  tool.

A wild gues: perhaps you could try doing an "init" (or powercycle)
before trying to boot from the Linux box.

(I don't know how RedHat ships, but I can't beleive they don't have
they have the relevant raw-socket support for the Linux user-space
packetfiltering drain-bamage.)