Dear Alberto,
Thanks for your comments. Most of them will be addressed in an update
version after WGLC among with other comments we may received. Detailed
replies in lines.
Best regards,
Sheng
-----Original Message-----
From: Alberto García [mailto:[email protected]]
Sent: Tuesday, April 20, 2010 6:25 PM
To: 'marcelo bagnulo braun'; [email protected]
Cc: [email protected]
Subject: RE: [CGA-EXT] WGLC for draft-ietf-csi-dhcpv6-cga-ps-01.txt
Hi,
Some comments:
In section 4 (What CGA can do for DHCPv6), it would help to
describe the scenario in which CGAs can be used, i.e.
indicating which of the elements use CGA, and in which part
of the DHCP configuration process can be beneficial the use
of CGA. Even though the draft is not devoted to solutions, at
least it should be shown a scenario in which a possible
solution could be developed.
CGA can be used for all DHCP messages/processes as long as CGA is available.
We will make it clearer in the update version.
In fact, I do not clearly see why using CGA is an advantage in this
scenario: CGA are good to state that a node has the
authorization to use a given address, but it is not clear to
me that it is to say that a node has the authorization to act
as something (a DHCP server, a relay). For this, some
configuration is required to bind the 'authorization' to the
CGA address. How is this done?
You then say a possible way of achieving this
This kind of authorization is based on pre-configuration conditions. For
example, a node has been pre-configured a public key of a certain DHCP
server (or a trust anchor). We will make it clearer in the update version.
"The minimum level of pre-configuration is to
configure public keys on both parties of communication or have a
third party authority available for users to retrieve public keys."
Well, the nice thing of CGA is that you don't need to know in
advance keys, but addresses (and the addresses can be
securely bound to keys dynamically, by means of conveying the
CGA parameter data structure, which is verified to see that
the binding is correct).
Agree. However, there is no any restriction that CGA can be used with
authority information together. This draft does not propose any concrete
solution, but list the possibilities. Of course, we should explain clearly
the scenario without any pre-configuration. It will be in the update
version.
I think the configuration should be just the CGA address. But
then, if you need configuration, which is the benefit over IPsec?
AFAIU IPsec has a number of benefits on its own: it is the
current standard for use in DCHP exchange, it allows
negotiation of security parameters so it is more secure than
CGAs... The nice thing of CGAs is that in general you use
them without configuring anything or just by using them as
addresses (you just configure the DNS, and that's all).
The same with above.
May be I'm not understanding properly this part. Can you be
more specific?
In addition, as a problem statement document, it should be
more exhaustive in detailing all the problems which can be
addressed by CGAs (even though there is no detail on the solution).
If you meant the scenario without any pre-configuration, it will be included
in the update version. If you think there are other missing, please point
out. We are glad to include.
---
In the second paragraph of the introduction you say:
"By using the associated public& private keys
as described by SEcure Neighbor Discovery (SEND)
[RFC3971], CGAs can
protect the Neighbor Discovery Protocol (NDP) [RFC4861], i.e. they
can provide address validation and integrity protection for NDP
messages."
Although this is true, of course, I don't see the point in
just considering here0020one protocol which use CGAs. The
draft is about configuring CGAs, and this CGAs can be used
for any purpose (SEND, SHIM6, any other). Here it seems there
is a specific dependency on SEND, which I think is not the case.
I would replace with:
"CGAs are used in protocols such as SEND [RFC3971] or SHIM6
[RFC5533]." or something similar.
It will be addressed in the update version. Many thanks for your valuable
comments.
Best regards,
Sheng
----
Regards,
Alberto
| -----Mensaje original-----
| De: [email protected] [mailto:[email protected]] En
| nombre
de
| marcelo bagnulo braun
| Enviado el: martes, 20 de abril de 2010 10:23
| Para: [email protected]
| CC: [email protected]
| Asunto: [CGA-EXT] WGLC for draft-ietf-csi-dhcpv6-cga-ps-01.txt
|
| Hi,
|
| This note issues the WGLC for draft-ietf-csi-dhcpv6-cga-ps-01.txt
| Please, review the document and send your comments before
april the 10th.
|
| For your convenience, you can find the document at
| http://datatracker.ietf.org/doc/draft-ietf-csi-dhcpv6-cga-ps/
|
| Regards, marcelo
|
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