[156672] in North American Network Operators' Group
Re: Big Temporary Networks
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Fri Sep 21 22:43:22 2012
Date: Sat, 22 Sep 2012 11:42:08 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: William Herrin <bill@herrin.us>
In-Reply-To: <CAP-guGXKKj9T5jsjZ1HDScp7HKLgf0EEipg4AdV1--DDLuA8aQ@mail.gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
William Herrin wrote:
>> You miss multicast storm caused by DAD.
> Second, in the hotspot scenarios where this is likely to be a problem
> (in IPv4 -or- IPv6) it's addressed by the "AP isolation" feature
As you stated
: I think Masataka meant to say (and said previously) that the DHCP
: request from the wifi station is, like all packets from the wifi
: station to the AP, subject to wifi's layer 2 error recovery.
that is not a problem for IPv4 ARP and DHCP.
> that's getting close to omnipresent even in the low end APs. With this
> feature enabled, stations are not allowed to talk to each other over
> the wlan; they can only talk to hosts on the wired side of the lan.
> The DAD packets are simply never sent to the other stations.
You are saying to disable DAD, which is a violation of SLAAC.
> In theory there are some problems with this. In practice, it's in wide
> deployment and has been demonstrated to work just fine.
Tell it to IETF to modify SLAAC to exclude DAD.
Masataka Ohta
