[trill] RD Review of draft-ietf-trill-address-flush-00

[Henning Rogge <[e-mail]>]

Hi,

Jonathan Hardwick asked me to review the initial revision of the TRILL
Address Flush draft.

I can easily see the use case for this functionality with TRILL aware
RBridges that have additional knowledge about leaving (or even
"roaming" end-devices). The speedup for removing the MAC addresses
could be essential for performance in some scenarios.



I have a couple of comments and questions to chapter 2:

- is it a normal use case to have "n" nicknames and "m" VLAN blocks
and want to remove all combinations of all of them or do you expect on
of the list to have size 1 normally?

- I would suggest moving the description of each "TLV" for the Address
Flush Message into a sub-chapter. This allows to break the "wall of
text" for each TLV and makes adding a small ascii-art for each TLV
possible, making the TLVs much easier to read and to reference (see
below).

- the difference between the "VLAN Block Case" (2.1) and "Extensible
Case" (2.2) feels artificial. Why not add a "VLAN block TLV", which
contains the list of VLAN start/end fields?

- maybe the Nicknames could also be moved into a TLV, allowing to
process the whole message with a single TLV based parser.

- I would suggest adding a new IANA registry to the draft to contain
the TLV types. This will make it easier to add types in later IETF
documents.



Example for new (sub)chapter for TLVs:


Chapter x.y: Address Flush Message TLVs

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type          | Length        | TLV Data...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type:     1 octet type field
Length:   length of the TLV data in octets without Type and Length field.
TLV Data: TLV specific data



Chapter x.y.1: Nickname TLV

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBD)    | Length        | Nickname 1                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nickname 2                    | Nickname K-nicks              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The Nickname TLV contains a list of Nicknames the Address Flush
Message refers to.

The length of the Nickname TLV is always an even number of octets.



Chapter x.y.2: VLAN block TLV

...




Henning Rogge

Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
Kommunikation, Informationsverarbeitung und Ergonomie FKIE
Kommunikationssysteme (KOM)
Fraunhofer Straße 20, 53343 Wachtberg, Germany
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