Subject: Re: [dhcwg] What sorts of services does DHCP configure?

From: "Simon Hobson" <[email-masked]>
Date: Thu, 17 Oct 2013 12:34:09 +0100

Sten Carlsen wrote:
> This makes me think of the Internet of Things. Would the
> configuration of all those things be done over DHCP and another
> question, who will decide those configurations?

Well one technique that seems to be getting very popular is autoconf & zeroconf & multicast DNS. Take for example Apple's streaming protocol for playing media across their various devices. AIUI, the devices will use autoconf IPv6 addresses, and multicast DNS to find devices on the network. So (for example) connect an Apple TV to your network and it "just appears" as a video output device for an iPad or iPhone.

Similar things are happening with printers etc. mDNS allows devices to find the printer without the user having to bother about IP addresses, ports, etc.

Ted Lemon wrote:
>Although there is an NTP option for DHCP, and it is implemented in some cases, it is not widely used, for reasons
> that seem obvious to me: NTP is required for replay detection, and so trusting the DHCP server to tell you what
> your NTP server is isn't secure.

It that much different to most options the DHCP server sends ? Eg, if you don't trust the DNS to be accurate then you are going to have fairly limited networking. Assuming you hard code you NTP, then there's nothing to say that on <any random network> that the traffic isn't blocked and/or interfered with.