Requested revision
Standard: | 802.1Q-2011 | Clause: | 10.7.5.2 |
Clause title: | Flush! |
Rationale for revision
The current behavior of the Registrar state table (Table 10-4) does not
cause a "Lv" (10.7.6.14) to be sent when in the "IN" state and a Flush!
event occurs.
This results in the permanent registration of the associated attribute,
as the MRP application is never made aware of the Registrar's state change.
Proposed text
Regarding Table 10-4, state "IN", event "Flush!":
Replace "MT"
with
"
Lv
MT
"
Impact on existing networks
The intention of the informatively named state names "IN" and "MT" is
maintained when a "Lv" is signaled, as this will trigger a
MAD_Leave.indication to the MRP application.
The intentions outlined in 10.3.1.1 will similarly be maintained by this
change, specifically, quoting from the end of 10.3.1.1:
"""
For implementations running over RSTP or MSTP, this gives rise to the
risk of information loops when Port
roles change; because of the store and forward nature of attribute
propagation and the potentially rapid
transitions of Port roles (compared to the relatively slow transitions
that occurred with STP), these can arise
even when there are no data loops.
To prevent such information loops from occurring, the information held
by MAD’s Registrars for a Port (i.e.,
information registered on a Port as a result of protocol activity on the
LAN to which that Port is connected)
is discarded whenever the Port transitions from an Alternate port or
Root Port role to become a Designated
Port. No such discard is needed for changes in the other direction,
i.e., changes from Designated Port to Root
Port or Alternate Port.
"""
Originator
Name: | Aaron Stewart, Bob Noseworthy | Email: | astewart@iol.unh.edu; ren@iol.unh.edu |
Affiliation: | University of New Hamsphire's InterOperability Lab | ||
Submitted: | 2012-08-23 |