On Oct 9, 2013, at 11:26 AM, Cullen Jennings (fluffy)
<fluffy(_at_)cisco(_dot_)com> wrote:
Help educate me on this a bit - I don't see all the things that get requested
of DHCP. What are some examples of things where people are request FQDN where
IP would be better. I think having some real examples that have come up would
make it easier to see what advice is needed.
DNS server IP address. NTP server IP address. Router IP address (not in
DHCPv6, of course). AFTR IP address. Basically, network infrastructure IP
addresses.
Bear in mind that the set of services configured by DHCP ought to be pretty
small—just things that really are local network infrastructure services, not
things that are specific to the host and not to the network. It's not even
clear to me that NTP ought to be configured by DHCP, and indeed in most cases
it is not, despite there being an RFC describing how to do it.
Considering the case of SIP, when you configure SIP I think that's probably a
configuration that shouldn't change as the phone moves from network to network.
So it shouldn't be configured by DHCP. In the case where the phone happens
not to be likely to move from network to network, you could _get away_ with
using DHCP. But a solution that would work for phones that _do_ move from
network to network would also work for phones that do not, and that solution
would therefore be preferable, particularly as an MTI solution, since it
addresses all use cases.
As I mentioned in the IESG discussion, it is a shame that aggsrv didn't become
a working group, since it was intended to address this specific problem, at
least as I understood it.