Subject: Re: [dhcwg] draft-ietf-dhc-dhcpv6-opt-netboot-05 - how to proceed?

From: "H. Peter Anvin" <[email-masked]>
Date: Thu, 05 Nov 2009 18:36:33 -0800

On 10/23/2009 09:08 AM, Ted Lemon wrote:
> On Oct 22, 2009, at 12:41 PM, Thomas Narten wrote:
>> Well, I wasn't all that clear in my first note either! I'm really
>> hoping for the same. I'd be happy to support load balancing, but only
>> if was a real requirement coming from the folk who are using netboot
>> and have experience with it. Otherwise, I'd prefer that we keep things
>> simple.
> 
> I may be speaking out of turn here, but I think that the fact that this
> draft explicitly recommends http over tftp for downloading the boot file
> will solve a lot of the load problems that exist with the current
> DHCP/tftp boot mechanism in DHCPv4.   As I understand it, the primary
> problem with netbooting in IPv4 is that tftp is such a low-performance
> solution (due to the lock-step nature of the protocol), not that tftp
> boot servers get overloaded during power events.
> 

[Sorry for the late reply]

TFTP boot servers, because of the lockstep protocol and generally very
simple implementation of clients, is subject to a failure-capture effect
where a "losing" client ends up continuing to "lose" and thus end up
with total boot failures.  This is one of many reasons why TCP/HTTP is a
much better option.

I'm more than willing to list others ;)

	-hpa