Re: [netlmm] TLV header in the GRE Keys draft

["Ahmad Muhanna" <[e-mail]>]

Hello Vijay,

Text looks fine. 
Will take care of it during AUTH48.

Cheers!

Regards,
Ahmad
 

> -----Original Message-----
> From: Vijay Devarapalli [mailto:[e-mail]] 
> Sent: Tuesday, May 19, 2009 6:46 PM
> To: NETLMM Mailing List; Muhanna, Ahmad (RICH1:2H10)
> Cc: Jari Arkko
> Subject: FW: TLV header in the GRE Keys draft
> 
> Hello folks,
> 
> I had an offline discussion with the Ads on restricting the 
> possible valid values for the 'Next Header' field in the TLV 
> header in draft-ietf-netlmm-grekey-option-09.txt. See below. 
> Jari suggested making this change during the AUTH48 stage. 
> Here is the suggested text change for this
> 
> OLD:
> 
>   Next Header
> 
>       8-bit unsigned integer which indicates the protocol 
> number of the
>       payload header following this TLV header.  It is set to the
>       protocol number as assigned by IANA at the following
>       http://www.iana.org/assignments/protocol-numbers. e.g., 
> if an IPv6
>       header follows, it should be '41'; '47' if it is a GRE 
> header that
>       follows.
> 
> NEW:
> 
>   Next Header
> 
>       8-bit unsigned integer which indicates the protocol 
> number of the
>       payload header following this TLV header.  The valid 
> values for this
>       field are '4' (IPv4), '41' (IPv6), '47' (GRE), and '50' (ESP).
>       The values are taken from the protocol numbers as 
> assigned by IANA at
>       the http://www.iana.org/assignments/protocol-numbers. All others
>       values are not permitted. If the MAG or the LMA node 
> receives a packet
>       with the TLV header where the 'Next Header' field is 
> set to anything
>       other than the above mentioned four protocols, it 
> SHOULD silently
>       discard the packet.
> 
> Feel free to modify the text.
> 
> Vijay
> 
> ------ Forwarded Message
> From: Jari Arkko <[e-mail]>
> Date: Tue, 05 May 2009 19:44:28 +0300
> To: Vijay Devarapalli <[e-mail]>
> Cc: Pasi Eronen <[e-mail]>
> Subject: Re: TLV header in the GRE Keys draft
> 
> I think that sounds reasonable. Bring it up in AUTH48.
> 
> Jari
> 
> Vijay Devarapalli wrote:
> > Hi Jari, Pasi,
> >
> > I think we need to restrict the values for the "Next 
> Header" field in 
> > the TLV header in draft-ietf-netlmm-grekey-option to just 
> IPv4, IPv6 or GRE.
> >
> > A typical MAG or LMA implementation would turn off most of 
> the ports, 
> > allow a certain number of ports and only process a limited 
> number of 
> > control plane packets. The TLV header causes issues. 
> Basically on top 
> > of the DS-MIPv6 port (since the UDP header is always there 
> before the 
> > TLV header), you can carry pretty much any protocol. All the 140 
> > protocols described on the IANA page can carried inside the 
> TLV header.
> > 
> http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtm
> > l
> >
> > An implementation can address this by dropping anything other the 
> > relevant protocols after the TLV header. But I am not sure if all 
> > implementers will do this. So it would better if we specify in 
> > draft-ietf-netlmm-grekey-option that only IPv4, IPv6 or GRE 
> can follow 
> > the TLV header. If there is anything else, the MAG or the 
> LMA should drop the packet.
> >
> > I just noticed that this document got approved. So can we add this 
> > restriction in the AUTH48 stage?
> >
> > Vijay
> 
>