Big Temporary Networks

Masataka Ohta mohta at
Sat Sep 22 02:42:08 UTC 2012

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

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