Subject: [MEXT] New revision for rfc3775bis; new text for issue #17 (Multi-homed mobile node can cause routing loop between home agents)

From: "Charles E. Perkins" <[email-masked]>
Date: Wed, 04 Mar 2009 15:26:28 -0800

Hello folks,

For issue #17, I have made the following revision to the text,
in section 15.1.  "Threats".

OLD:

>       In conclusion, there are Denial-of-Service, Man-in-the-Middle,
>       Confidentiality, and Impersonation threats against the parties
>       involved in sending legitimate Binding Updates, the threat of
>       routing loops when there are multiple home agents, and Denial-of-
>       Service threats against any other party.

NEW:

>       A malicious mobile node associated to multiple home agents could
>       create a routing loop amongst them.  This can be achieved when a
>       mobile node binds one home address located on a first home agent
>       to another home address on a second home agent.  This type of
>       binding will force the home agents to route the same packet among
>       each other without knowledge that a routing loop has been created.
>       Such looping problem is limited to cases where a mobile node has
>       multiple home agents.  One possible deployment that may encounter
>       such issue is the 3GPP System Architecture Evolution (SAE), where
>       it permits a mobile device to be associated to multiple home
>       agents.  These home agents differentiate the different packet
>       networks that the mobile device has association to (e.g. home,
>       office).  For the single home agent case, a policy at the home
>       agent would prevent the binding of one home address to another
>       home address hosted by the same home agent.
> 
>       The potential problems caused by such routing loops in this
>       scenario can be substantially reduced by use of the Tunnel-Limit
>       Option specified in RFC 2473 [9].
> 
>       In conclusion, there are Denial-of-Service, Man-in-the-Middle,
>       Confidentiality, and Impersonation threats against the parties
>       involved in sending legitimate Binding Updates, the threat of
>       routing loops when there are multiple home agents, and Denial-of-
>       Service threats against any other party.

Regards,
Charlie P.
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From: Vijay Devarapalli <[email-masked]>
Date: Wed, 04 Mar 2009 15:35:41 -0800

Hi Charlie,

I suggest one minor change.

Charles E. Perkins wrote:

>>       agents.  

A mobile node could always use multiple home agents. 3GPP SAE 
architecture does not introduce this. So I suggest a slight modification 
that removes the text related to 3GPP SAE.

NEW

    A malicious mobile node associated to multiple home agents could
    create a routing loop amongst them.  This can be achieved when a
    mobile node binds one home address located on a first home agent
    to another home address on a second home agent.  This type of
    binding will force the home agents to route the same packet among
    each other without knowledge that a routing loop has been created.
    Such looping problem is limited to cases where a mobile node has
    multiple home agents and is permitted to be associated with the
    multiple home agents. For the single home agent case, a policy at
    the home agent would prevent the binding of one home address to
    another home address hosted by the same home agent.

Vijay

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From: "Charles E. Perkins" <[email-masked]>
Date: Fri, 06 Mar 2009 16:21:42 -0800

Hello Vijay,

I have made the suggested change.  It seems
reasonable to me.

Regards,
Charlie P.

Vijay Devarapalli wrote:
> architecture does not introduce this. So I suggest a slight 
> modification that removes the text related to 3GPP SAE.
>
> NEW
>