Re: [DNA] Re: RS/RA Exchange

[Bernard Aboba <aboba@internaut.com>]

> On WLAN with switched ethernet, broadcasts go over the wireless link.

This depends on whether a station is a member of the same broadcast
domain as the VLAN on which the broadcast originated.  Remember, APs are
capable of handling multiple VLANs nowadays. So if there are no stations
that are members of the same VLAN as the broadcast frame in question, it
won't be forwarded over the Wireless Medium (WM).

> Most switches today treat multicast as broadcast.

Today's switches typically support IGMP snooping and/or GARP Multiast
Registration Protocol (GMRP), so that multicast in fact need not be
handled the same as broadcast.

> A device which can transmit onto the wireless link will have its
> vrrp or all-routers messages bridged onto the wired link

I think you are assuming that an IEEE 802.11 wireless access point is a
bridge. This is not the case.  IEEE 802.11-1999 does not require an AP to
implement spanning tree protocol (STP) and APs do not "learn" or forward
in the same manner that bridges do.  For example, an IEEE 802.11 AP will
not forward a frame received on the DS to the WM unless the destination
address is one of a station that has associated to the AP.