I got to the same place as another recent poster.

I'm using V3.8-3 of the firmware, the netboot from the online form
with broken firmware set to yes, and a set of NFS mounts constructed
as per the NetBSD documentation on setting up a diskless workstation.

I was able to tcpdump the entire transaction.  There's roughly 472
lines of output, but it can be summarized pretty easily:

Things start off pretty well.  I use the following command line from
the SRM console of alpha:

>>> boot ewa0 -prot bootp

And this is what tcpdump has to say:

12:09:08.794054 0.0.0.0.bootpc > 255.255.255.255.bootps:  [udp sum ok] xid:0x465ebe49 vend-rfc1048 (ttl 32, id 31613, len 328)
12:09:08.865591 duchess.twilley.org.bootps > alpha.twilley.org.bootpc:  [udp sum ok] xid:0x465ebe49 Y:alpha.twilley.org S:duchess.twilley.org sname "duchess.twilley.org" file "netbsd.alpha" vend-rfc1048 SM:255.255.255.0 DG:mulan.twilley.org NS:duchess.twilley.org HN:"alpha" RP:"/v1/netbsd/alpha/root/" [tos 0x10]  (ttl 16, id 0, len 328)
12:09:08.867919 arp who-has duchess.twilley.org tell alpha.twilley.org
12:09:08.868394 arp reply duchess.twilley.org is-at 0:20:af:b4:a7:1a
12:09:09.154060 alpha.twilley.org.50061 > duchess.twilley.org.tftp:  [udp sum ok] 21 RRQ "netbsd.alpha" (ttl 32, id 6006, len 49)
12:09:09.556031 duchess.twilley.org.2251 > alpha.twilley.org.50061:  [udp sum ok] udp 516 (ttl 64, id 56832, len 544)
12:09:09.557432 alpha.twilley.org.50061 > duchess.twilley.org.2251:  [udp sum ok] udp 4 (ttl 32, id 56595, len 32)
12:09:09.567103 duchess.twilley.org.2251 > alpha.twilley.org.50061:  [udp sum ok] udp 516 (ttl 64, id 29545, len 544)
12:09:09.568213 alpha.twilley.org.50061 > duchess.twilley.org.2251:  [udp sum ok] udp 4 (ttl 32, id 62429, len 32)
[... more of the TFTP transfer elided ...]

Okay, alpha sends out a BOOTP request, duchess responds with useful
information, alpha asks who duchess is, duchess responds, alpha
requests the netbsd.alpha boot file from duchess, the file gets
transferred and executed.  Then what?

Stuff gets displayed on alpha's screen about OSF PAL stuff, some other
stuff, then boot flags, and an attempt to get the kernel by name of
netbsd.

This is what comes over the wire:

12:09:13.242850 0.0.0.0.bootpc > 255.255.255.255.bootps:  [udp sum ok] vend-rfc1048 DHCP:DISCOVER (ttl 4, id 0, len 576)
12:09:13.255685 duchess.twilley.org.bootps > alpha.twilley.org.bootpc:  [udp sum ok] Y:alpha.twilley.org S:duchess.twilley.org sname "duchess.twilley.org" file "netbsd.alpha" vend-rfc1048 DHCP:OFFER SID:duchess.twilley.org LT:21600 SM:255.255.255.0 DG:mulan.twilley.org NS:duchess.twilley.org HN:"alpha" RP:"/v1/netbsd/alpha/root/" YD:"twilley.org" RN:10800 RB:18900 DN:"twilley.org" [tos 0x10]  (ttl 16, id 0, len 371)
12:09:15.268537 0.0.0.0.bootpc > 255.255.255.255.bootps:  [udp sum ok] secs:2 vend-rfc1048 DHCP:DISCOVER (ttl 4, id 0, len 576)
12:09:15.271760 duchess.twilley.org.bootps > alpha.twilley.org.bootpc:  [udp sum ok] secs:2 Y:alpha.twilley.org S:duchess.twilley.org sname "duchess.twilley.org" file "netbsd.alpha" vend-rfc1048 DHCP:OFFER SID:duchess.twilley.org LT:21600 SM:255.255.255.0 DG:mulan.twilley.org NS:duchess.twilley.org HN:"alpha" RP:"/v1/netbsd/alpha/root/" YD:"twilley.org" RN:10800 RB:18900 DN:"twilley.org" [tos 0x10]  (ttl 16, id 0, len 371)
12:09:19.287101 0.0.0.0.bootpc > 255.255.255.255.bootps:  [udp sum ok] secs:6 vend-rfc1048 DHCP:DISCOVER (ttl 4, id 0, len 576)
12:09:19.303759 duchess.twilley.org.bootps > alpha.twilley.org.bootpc:  [udp sum ok] secs:6 Y:alpha.twilley.org S:duchess.twilley.org sname "duchess.twilley.org" file "netbsd.alpha" vend-rfc1048 DHCP:OFFER SID:duchess.twilley.org LT:21600 SM:255.255.255.0 DG:mulan.twilley.org NS:duchess.twilley.org HN:"alpha" RP:"/v1/netbsd/alpha/root/" YD:"twilley.org" RN:10800 RB:18900 DN:"twilley.org" [tos 0x10]  (ttl 16, id 0, len 371)
12:09:27.312842 0.0.0.0.bootpc > 255.255.255.255.bootps:  [udp sum ok] secs:14 vend-rfc1048 DHCP:DISCOVER (ttl 4, id 0, len 576)
12:09:27.325256 duchess.twilley.org.bootps > alpha.twilley.org.bootpc:  [udp sum ok] secs:14 Y:alpha.twilley.org S:duchess.twilley.org sname "duchess.twilley.org" file "netbsd.alpha" vend-rfc1048 DHCP:OFFER SID:duchess.twilley.org LT:21600 SM:255.255.255.0 DG:mulan.twilley.org NS:duchess.twilley.org HN:"alpha" RP:"/v1/netbsd/alpha/root/" YD:"twilley.org" RN:10800 RB:18900 DN:"twilley.org" [tos 0x10]  (ttl 16, id 0, len 371)

Four times alpha sends out DHCP:DISCOVER messages.  Not TFTP messages
for "netbsd", but DHCP messages.  duchess responds with all the
appropriate information, including a root path.  After four attempts,
alpha complains that it cannot get the kernel.

Am I missing something here?  I've looked at the documentation, but
there seems to be no way to make this thing mount the root path and
"just do it".  Are there flags that I should supply?  Help?

Jack.
(now a member of the mailing list)
-- 
Jack Twilley
jmt at twilley dot org
http colon slash slash www dot twilley dot org slash tilde jmt slash