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Re: comments on draft-ietf-shim6-proto-05.txt {2}
El 08/10/2006, a las 17:09, Deguang Le escribió:
agree
basically the usage of the BROKEN flag is intended for when the host
knows thanks to local information that a locator is temporarily
unavailbale/unreachable, so it can mark it as such, so that the peer
doesn't use it for communicating.
I agree with you, it is a good way to deal with the temporary failure
of
locator using the BROKEN flag.
However, if the locator is permanently unavailbale/unreachable say due
to mobility or rehoming, I think it is not necessary to keep the
unavailable locator in the locator set. Right?
both approaches are possible and i guess that your viewpoint makes more
sense
As mentioned in the other email, another option would be to remove
from the locator set using a Update message, but i guess this option
is cheaper in terms of processing (cheaper security checks)
As for security check, I am not familiar with security issue, so I
don't
know why the Locator Preference option need not verification check. ^-^
Does anyone provide some explanations about it? Thank in advance.
to change the locator set you need to include security information
either HBA or CGA. In the HBA case, this is a hash calculation and in
the CGA is a public key operation. OTOH, to change the preferences,
only a cookie is used, so it is much cheaper. This is so because
changing the locator set may result in all types of redirection attacks
from off path attacker. However, changing the preferences can only be
done by on path attacker and it would result in potentially changing
the locator used (if the peer takes into account the preferences).
Hence the protection of one operation is less than the other.
Besides, the above explanation for "TEMPORARY" is still not clear
for me. What are the more stable addresses and what are the less
stable addresses?
the goal here is that if the host knows that there are some addresses
that may change rapidly, it can mark them as such, so that the peer
use more aggresive failure detection mechanisms on that address.
I think it is an interesting usage although it is not easy to determine
which addresses belong to more stable or less stable. :-)
In the case of MIP a HoA is a more stable address and a CoA is a less
stable address
In my own veiw, I don't think the HoA is the more stable address and
the
CoA is the less stable address because the mobile node may stay at any
place including the home network or foreign network at any time.
For example, a mobile node may access to the Internet through some
foreign network, then it may moves between the foreign networks, which
are far from the home network. In this case, the HoA may never be
usable
during the whole communication period. Therefore, we could not regard
the HoA as the more stable address. Right?
i don't think so...
the Hoa is always reachable because the Home Agent would forward the
packets delivered to the HoA (the performance would be worse though)
The CoA is only usable while the node is in the visited network, hence
the HoA is much more stable than the CoA even in the scenario that you
describe, agree?
I think it is better if this draft could provides some special
situations about them. Morever, I also can not understand how the
TEMPORARY can be used to distinguish them.
The usage would be that it will include the Temporary flag when
conveying CoA information in the locator set.
As my above statements, I think it is not suitable to tag the CoA as
Temporary. Right? :-)
see above
Do you think that additional text is required to explain this?
Yes, I think these flags are very important in order to put the Locator
Preference option in real use, we need to formulate these flags'
functions and their usage (e.g. applied situations) more clearly.
I am ok with addin additional text for the broken flag since there is
no text describing it... i am willing to include additional text on the
temporary flag, but not sure what to include there though...
Regards, marcelo
With best regards,
Deguang
Regards, marcelo
Cheers,
Deguang
Geoff Huston schrieb:
Hi,
This note starts the WG Last Call for comments on the three "base"
Shim6 documents:
draft-ietf-shim6-proto-05.txt "Level 3 multihoming shim
protocol"
draft-ietf-shim6-hba-01 "Hash Based Addresses (HBA)"
draft-ietf-shim6-failure-detection-06 "Failure Detection and
Locator Pair Exploration
Protocol for IPv6
Multihoming"
They can be found at:
http://www.ietf.org/internet-drafts/draft-ietf-shim6-proto-05.txt
http://www.ietf.org/internet-drafts/draft-ietf-shim6-hba-01.txt
http://www.ietf.org/internet-drafts/draft-ietf-shim6-failure-
detection-06.txt
Please review the documents carefully, and send your feedback to
the SHIM6 list. Please also indicate whether or not you believe
that these documents
are ready to go to the IESG for publication as a set of Proposed
Standards.
This Working Group Last Call will end in two weeks, on the 12th
October 2006 at 0800, UTC+10
Thanks,
Geoff & Kurtis