STEP 2, fixing dhclient behaviour with multiple interfaces

Terry Lambert tlambert2 at
Thu Jul 31 01:18:22 PDT 2003

Tony Finch wrote:
> Terry Lambert <tlambert2 at> wrote:
> >I can't wait for IPv6 stateless autoconfiguration plus SLPv2 so
> >we can get rid of all this DHCP crap once and for all.  8-(.
> >SLPv2 is used to find the gateway and DNS server, and after that,
> >everything "magically works".
> I thought that the gateway address is (already) set up using
> RFC 2461 router and prefix discovery.

Won't work for any U.S. Cable modems or DSL, which is based on
ATM (which is an NBMA-type link).  It also doesn't work for
ISDN ("iDSL"), which is an SDMS-type link and doesn't have full
prefix information available.

So basically, if you have broadband, it won't work.

I think that any broadcast system, like 802.11a, 802.11b,
802.11g, Motorolla Canopy, etc.. will also have issues, since
the machines are implicitly multihomed for the nearest one.

Finally, I haven't seen a router with ND turned on, if it was
even supported, so it wouldn't advertise or respond to any
solicitations to advertise (basically, you'd end up with an
ability to use this to fire off indirect DOS attacks against
third parties, so it tends to be disabled, or at least that
was the explanation I was given).  Basically, this leaves the
client machine playing by the ND rules in the "INCOMPLETE"
state, with no one to talk to.

Microsoft actually solved this problem for IPv4 in link.local
with their "Internet Connection Sharing" product at one time,
but then went back to DHCP in later releases for reasons unknown
(maybe because of 802.11 base-station-mode cards becoming
available for Windows... who knows?).

In any case, ND is kind of like DHCP, in that explicit support
for the protocol is needed in order for both the client and
server to communicate, which is kind of what I thought people
needed to get away from when I was talking about losing DHCP.

-- Terry

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