[trill] ESADI draft change suggestion

[Sujay Gupta <[e-mail]>]

Hi,

1)

The ESADI protocol objectives as stated in the draft-04, IMO needs added 
statements.
Section 1: "Introduction"
 >>

The ESADI
    protocol's potential advantages over data plane learning include the
    following:

    1. Security advantages:..
    2. Fast update advantages:..
<<

w.r.t to Security advantages, albeit ESADI can make a authenticated entries an insecure ESADI increases
the security vulnerability then without it. My recommendation is to recommend a SHOULD clause to implement
security features. A secured deployment of TRILL may choose to live with a unsecured ESADI ( & therefore
possibly a more efficient/lighter ESADI); whilst a TRILL plane bridging 3rd party aggregation and application
layers may choose for trusted/secured model.

2)

This is w.r.t to learning of ESADI entries and timing them out. As per RFC 6325, the entries are expected
to be removed only by the originating RBridge.
>>
Section 4.8.3
"The situation is different for end-station address information acquired via the TRILL ESADI protocol.
It is up to the originating RBridge to decide when to remove such information from its ESADI LSPs
(or up to ESADI protocol timeouts if the originating RBridge becomes inaccessible)."
<<
  For robust behavior it would be better to timeout the entries without depending on ESADI, the reason
is a (wrong)ESADI directed forwarding can cause persistent traffic loss, unlike a best effort flood everywhere
situation. Therefore my recommendation is the specs should not 'mandate' the timing out behavior.

Best Regards,
-Sujay