Re: [trill] Eric Rescorla's No Objection on draft-ietf-trill-address-flush-05: (with COMMENT)

[Donald Eastlake <[e-mail]>]

Hi Eric,

On Tue, Feb 6, 2018 at 10:04 PM, Eric Rescorla <[e-mail]> wrote:
> Eric Rescorla has entered the following ballot position for
> draft-ietf-trill-address-flush-05: No Objection
>
> ...
>
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
>
> This is probably a dumb question but I notice that there's no
> filtering here for for example, VLAN IDs which the sending agent
> doesn't seem to be relevant for. Can you explain why that's not
> needed/desirable?

I'm not 100% sure I understand you question but it seems like you are
suggesting that an RBridge RB1 receiving an Address Flush message from
RB2 for VLAN X might ignore that message if it thinks VLAN X isn't
relevant to the sending RB2. (If VLAN X is not relevant to the
receiving RBridge RB1 then there won't be any remembered addresses at
RB1 and the flush message will have no effect.)

RBridges can in fact indicate the VLANs they are "interested in" but
one effect of doing so is that they get sent all the broadcast traffic
in that VLAN and all the unicast traffic where the attachment of the
destination MAC is unknown, and, except to the extent that multicast
pruning is implemented, all the multicast traffic in that VLAN. Assume
the sending RB2 is a management station that is participating as an
RBridge so that it can get all the link state information. Such a
management station might want to be able to issue an address flush
message in any VLAN but not want to indicate interest in most VLANs
because it does not want to receive multi-destination traffic in those
VLANs

Thanks,
Donald
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 Donald E. Eastlake 3rd   [phone] (cell)
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