Re: [nvo3] New Version Notification for draft-ietf-bfd-vxlan-08.txt

[Anoop Ghanwani <[e-mail]>]

Hi Greg,

In the case of the management VNI, are we trying to say that we would allow
any MAC address other than a tenant MAC address?  I would suggest some more
text be added to clarify what is permitted on the management VLAN.
Assuming that we want to allow any MAC other than a tenant MAC, how does
this get enforced?  In other words, what can be done for the network to
protect itself if a sender violates this?

One possible answer is to restrict the MAC address that may be used to one
that is owned by the VTEP or a "agreed on" multicast MAC address.  That
means the receiver only needs to validate for those, and just treats
everything else as data.

Also, for interoperability purposes, it would be best to specify that a
receiver MUST be able to handle any valid MAC address for the BFD session,
while a sender MAY pick any of them.

Thanks,
Anoop

On Sun, Nov 3, 2019 at 6:50 PM Greg Mirsky <[e-mail]> wrote:

> Hi Anoop,
> thank you for your comments and questions. Please find my notes in-line
> tagged GIM>>.
>
> Regards,
> Greg
>
> On Fri, Nov 1, 2019 at 4:24 PM Anoop Ghanwani <[e-mail]>
> wrote:
>
>> Hi Greg,
>>
>> A few comments.
>>
>> The draft has nits, specifically around the way the IPv6 address is
>> written.
>>
>> In section 4:
>>
>> BFD packet MUST be encapsulated ->
>>
>> BFD packets MUST be encapsulated
>>
>> GIM>> Thanks, will do.
>
>>
>> >>>
>>
>> Destination MAC: This MUST NOT be of one of tenant's MAC
>>          addresses.  The destination MAC address MAY be the address
>>          associated with the destination VTEP.  The MAC address MAY be
>>          configured, or it MAY be learned via a control plane protocol.
>>          The details of how the MAC address is obtained are outside the
>>          scope of this document.
>>
>> >>>
>> It looks like we have removed the option of using a well-known IANA
>> assigned MAC.  If so, why is the above a MAY and not a MUST?  What else can
>> it be?  One interpretation is that it can be anything unicast, or
>> multicast, as long as it's not a tenant MAC.  Is that the intent?  If so,
>> it would be better to state it that way.  Also (and this is purely
>> editorial), I think it would be better if the first sentence above were
>> moved to the end of the paragraph.
>>
> GIM>> Yes, you're right, we've removed that option and have removed the
> request to IANA. I also agree that " MAY be the address associated with the
> destination VTEP" is not the right choice of normative language. On the
> other hand, MUST might be too restrictive if BFD session is using the
> Management VNI. Would the following update address your concern:
> OLD TEXT:
>          Destination MAC: This MUST NOT be of one of tenant's MAC
>          addresses.  The destination MAC address MAY be the address
>          associated with the destination VTEP.  The MAC address MAY be
>          configured, or it MAY be learned via a control plane protocol.
>          The details of how the MAC address is obtained are outside the
>          scope of this document.
> NEW TEXT:
>          Destination MAC: If the BFD session is not using the Management
> VNI,
>          the destination MAC address MUST be the address
>          associated with the destination VTEP.  The Destination MAC
>          MUST NOT be one of the tenant's MAC addresses.
>         The MAC address MAY be configured, or it MAY be learned via
>         a control plane protocol. The details of how the MAC address
>         is obtained are outside the scope of this document.
>
>>
>> "The inner Ethernet frame carrying the BFD
>>    Control packet- has the following format:"
>>
>> Extraneous '-' after packet.
>>
> GIM>> Thanks, will do that too.
>
>>
>> Thanks,
>> Anoop
>>
>> On Fri, Nov 1, 2019 at 10:53 AM Greg Mirsky <[e-mail]>
>> wrote:
>>
>>> Dear All,
>>> the new version includes updates resulting from the discussions of
>>> Joel's comments in the RtrDir review of BFD over VXLAN draft, comments from
>>> Anoop, and Dinesh. On behalf of editors, thank you for your constructive
>>> comments and for sharing your expertise, all much appreciated.
>>> I hope we've addressed all your comments, and the draft can proceed
>>> further.
>>>
>>> Regards,
>>> Greg
>>>
>>> ---------- Forwarded message ---------
>>> From: <[e-mail]>
>>> Date: Fri, Nov 1, 2019 at 10:45 AM
>>> Subject: New Version Notification for draft-ietf-bfd-vxlan-08.txt
>>> To: Gregory Mirsky <[e-mail]>, Mallik Mudigonda <
>>> [e-mail]>, Sudarsan Paragiri <[e-mail]>,
>>> Vengada Prasad Govindan <[e-mail]>, Santosh Pallagatti <
>>> [e-mail]>
>>>
>>>
>>>
>>> A new version of I-D, draft-ietf-bfd-vxlan-08.txt
>>> has been successfully submitted by Greg Mirsky and posted to the
>>> IETF repository.
>>>
>>> Name:           draft-ietf-bfd-vxlan
>>> Revision:       08
>>> Title:          BFD for VXLAN
>>> Document date:  2019-11-01
>>> Group:          bfd
>>> Pages:          11
>>> URL:
>>> https://www.ietf.org/internet-drafts/draft-ietf-bfd-vxlan-08.txt
>>> Status:         https://datatracker.ietf.org/doc/draft-ietf-bfd-vxlan/
>>> Htmlized:       https://tools.ietf.org/html/draft-ietf-bfd-vxlan-08
>>> Htmlized:
>>> https://datatracker.ietf.org/doc/html/draft-ietf-bfd-vxlan
>>> Diff:
>>> https://www.ietf.org/rfcdiff?url2=draft-ietf-bfd-vxlan-08
>>>
>>> Abstract:
>>>    This document describes the use of the Bidirectional Forwarding
>>>    Detection (BFD) protocol in point-to-point Virtual eXtensible Local
>>>    Area Network (VXLAN) tunnels forming up an overlay network.
>>>
>>>
>>>
>>>
>>> Please note that it may take a couple of minutes from the time of
>>> submission
>>> until the htmlized version and diff are available at tools.ietf.org.
>>>
>>> The IETF Secretariat
>>>
>>>