Netbooting odyssey (SGI Indy)

[Meelis Roos <mroos@linux.ee>]

This mail is sent here to leave a googlable trace of my solutions to
Indy netboot problems.

I have a SGI Indy, 100 MHz R4600PC with onboard 10mbps ethernet. It was
running IRIX fine, serving as a X-Terminal (so I knew the networking was
functional).

I tried to netboot it from a Linux host (running Debian unstable).

First, bootpd answered with packets that had DF (don't fragment) bit
set. Turning PMTU off in /proc did not seem to help for some reason(???).
The command was echo "1" > /proc/sys/net/ipv4/ip_no_pmtu_disc

The solution to this one was hacking bootpd to do
        n = IP_PMTUDISC_DONT;
        if (setsockopt(s, SOL_IP, IP_MTU_DISCOVER, &n, sizeof(n))

This solved my bootp problem - Indy started to see the bootp answer. I
also did set my local port range to be below 32K - I normally had it
over 32K:
echo "10000 32766" > /proc/sys/net/ipv4/ip_local_port_range

Next problem was TFTP answers that didn't seem to reach the Indy. I had
rebooted the boot server box meanwhile and needed to reapply the /proc
changes, esp. PMTU discovery one. Don't know whether changing the port
range was actually necessary. The PMTU one changed TFTP answers to not
have DF bit set and Indy started to see them.

Also, to get any answer back to my Indy at all, I needed to use a
crossover cable to the boot server (with Intel NIC using e100 driver but
that's probably unimportant) because my Trendnet TE100-S55E 5-port
10/100 switch and Indy don't communicate (Indy doesn't seem to get any
answers, at least in PROM mode).

Finally, I was able to do boot -f bootp()/netboot-boot.img and see that
it does not find a working console on the Indy.

-- 
Meelis Roos (mroos@linux.ee)