[141970] in North American Network Operators' Group
Re: The stupidity of trying to "fix" DHCPv6
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Jun 15 01:48:11 2011
From: Owen DeLong <owen@delong.com>
In-Reply-To: <op.vw3dxxzltfhldh@rbeam.xactional.com>
Date: Tue, 14 Jun 2011 22:40:56 -0700
To: "Ricky Beam" <jfbeam@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jun 14, 2011, at 5:50 PM, Ricky Beam wrote:
> On Tue, 14 Jun 2011 18:16:10 -0400, Owen DeLong <owen@delong.com> =
wrote:
>> The point of /64 is to support automatic configuration and incredibly =
sparse host addressing.
>> It is not intended to create stupidly large broadcast domains.
>=20
> Several IETF (and NANOG) discussions say otherwise. While current =
hardware doesn't handle thousands of hosts, the protocol was designed =
for a future where that's not true. (there's a future where *everything* =
is network enabled... microwave oven, doorbell, weed whacker, =
everything.)
>=20
Sure, but, that future still doesn't need stupidly large numbers of =
hosts on a common link.
>> A /22 is probably about the upper limit of a sane broadcast domain, =
but, even with a /22
>> or 1022 nodes max, each sending a packet every 10 seconds you don't =
get to 100s of PPS,
>> you get 102.2pps.
>=20
> As I said, DHCP isn't the only source of traffic. Setup a 1000 node =
network today (just IPv4), and you will see a great deal of broadcast =
traffic (unless those nodes aren't doing anything.) With IPv6, it's all =
multicast (v6 doesn't have a "broadcast address") hinged on switches =
filtering the traffic away from where it doesn't need to be. The =
all-too-common Best Buy $20 white box ethernet switch does no multicast =
filtering at all. Pretty much all wireless hardware sucks at multicast =
- period. These are not things that can be fixed with a simple software =
update... if the silicon doesn't do it, *it doesn't do it*.
Depends on a number of factors. Yes, there are lots of issues. However, =
they aren't caused
by the small number of additional packets from DHCP.
Owen
