[savi] RFC6620 Page 15 - Data Trigger

["Leaf Yeh" <[e-mail]>]

I read RFC6620 again, still have some questions on it.

 

Section 3.2.3 Page 15 @ the state of NO_BIND

<quote>

Upon the reception through a Validating Port (VP) of a DATA packet

      containing IPAddr as the source address, the SAVI device SHOULD

      execute the process of sending Neighbor Solicitation messages of

      the Duplicate Address Detection process ... The DAD_NS messages are
not

      sent through any of the ports configured as Validating Ports.  The

      DAD_NSOL messages are sent through Trusted Ports (but, of course,

      subject to usual switch behavior and possible MLD snooping

      optimizations)... The state

      is moved to TENTATIVE.  The LIFETIME is set to TENT_LT (i.e., LT:

      =TENT_LT), the BINDING ANCHOR is set to VP (i.e., P:=VP), and the

      Creation time is set to the current value of the local clock.

</quote>

 

It seems the DAD_NS are not sent to 'any of VP', but sent to TP, after the
VP received a data packet, whose source address are not in binding table of
the SAVI device.

 

If this data packet use the prefix assigned on this link, we don't expect
the DAD_NA from the TP.

If the data packet use any IID-interface ID, i.e. the 64 bits of the source
address, the SAVI switch will set up a binding entry for each source
address.

 

Then I guess we lost the finer-grained SAV here, and only can rely on the
SAVI (on-link) prefix list to filtering the 'transit traffic'. Right?

 

I mean the malicious host can create a huge number of *valid* source address
within the on-link prefix. What was the design philosophy here?

 

How about send DAD_NS to the VP received data packet for the double-check in
the above process?

 

 

Best Regards,

Leaf