nanog mailing list archives

Re: v6 & DSL / Cable modems


From: "James R. Cutler" <james.cutler () consultant com>
Date: Fri, 6 Feb 2009 13:00:52 -0500

DHCP items are end system considerations, not routing network considerations.

The network operations staff and router configuration engineers do not generally concern themselves with end systems.

End systems generally are managed quite independently from the routing network. And, they are more subject to the vagaries of day to day business variability. Note the "one place" in the quoted message below.

The only overlap is broadcast forwarding for DHCP initiation.

Besides, configuration control is hard enough for router engineers without adding the burden of changing end system requirements. Adding the forwarding entries is almost too much already! ;)

So, for routing network operators to denigrate DHCP is probably due to lack of consideration of the end user system requirements. And those who denigrate DHCP and say "just hard code it" make end system management that much more difficult.

I still conclude that DHCP is a useful tool for both IPv4 and IPv6 systems.

        Cutler

On Feb 6, 2009, at 12:22 PM, sthaug () nethelp no wrote:

The problem is that DHCP seemed like a good idea at the time but it
doesn't make any sense today. We know that parsing complex binary data
formats is asking for security problems.

And parsing complex text data structures is better?

What we need is a simple, fast, efficient way to distribute the basic
information that a host needs to start sending and receiving packets
and a pointer to a place where additional location dependent
configuration information can be found. That would be: address +prefix,
gateway and (arguably) DNS and then something like a URL for a server
that has the config info. The system and applications can then load
information from the config server over HTTP in XML format or some such.

No, this information must be available in *one* place. It's called a
DHCP server. As an operator, this is clearly what I want, both for IPv4
and IPv6.

Steinar Haug, Nethelp consulting, sthaug () nethelp no


James R. Cutler
james.cutler () consultant com






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