Subject: [v6ops] Reminder: draft-ietf-v6ops-ivi-icmp-address WGLC

From: Fred Baker <[email-masked]>
Date: Sun, 8 Apr 2012 16:17:04 -0700

The working group last call for this draft announced last week continues for another week. Please feel free to comment on it.

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From: Randy Bush <[email-masked]>
Date: Mon, 09 Apr 2012 12:49:59 +0900

section 4 worries me.  i think it means that, if uprf filtering is in
play, either
  o the source of the packets must announce the well-known prefix, or
  o the router doing uprf filtering needs a static to the interface
    from which it may receive such packets.

are people really gonna do all this custom configuration?  reliably?

   Such routing advertisements are non-exclusive and should be accepted
   from any originating AS in an anycast fashion.

hmmm.  i wonder if we should advise the uprf filterer not to propagate
the announcement, and for non-uprf players to filter it as a martian?

randy

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From: Fred Baker <[email-masked]>
Date: Mon, 9 Apr 2012 09:11:15 -0700

> the announcement, and for non-uprf players to filter it as a martian?

Hmm

4.  Routing Considerations

   Addresses from the assigned address prefix are intended to be used as
   source addresses and not as destination addresses in the context of
   the public network.  As packets passing through the public network
   need to pass through conventional packet filters, including uRPF
   filters [RFC3704], this implies that the assigned address may be used
   in routing advertisements.  Such routing advertisements are non-
   exclusive and should be accepted from any originating AS in an
   anycast fashion.

For some reason, I have been thinking of this prefix as only being used in the ICMP message, not the IPv4 header. 

Could the authors comment on this please?

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From: Randy Bush <[email-masked]>
Date: Tue, 10 Apr 2012 13:52:09 +0900

> What does announcement mean here - is it the ICMP packet or is it the
> routing advertisements?  Also what does non-urpf players mean?

announcements are routing announcements.  i have never heard the term
used in the data plane.

by non-uprf players, i meant routers which are not applying urpf
filters.  is there a reason they should propagate the announcement of
your wka?

randy

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From: Randy Bush <[email-masked]>
Date: Tue, 10 Apr 2012 14:15:00 +0900

> RAMJI:  Even if a router is a non-urpf player, the subsequent routers to
> which the route is propagated could do uRPF, hence should they not
> receive the routing advertisement?

so all routers in the entire internet should have a route to your wka to
all their interfaces?

randy

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From: Joel jaeggli <[email-masked]>
Date: Mon, 09 Apr 2012 23:40:29 -0700

>     from which it may receive such packets.

if you're doing strict mode with customers I would imagine that each one
would be required to advertise this prefix in order to originate packets
from this source.

It's seems clear to me that the goal is that packets from this source
address be unequivically accepted which as I've stated before strikes me
as a rather bad idea since I cannot by definition know their source.

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> https://www.ietf.org/mailman/listinfo/v6ops
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From: "Ramji Vaithianathan (rvaithia)" <[email-masked]>
Date: Mon, 9 Apr 2012 21:43:50 -0700

These addresses are source addresses in the L3 (IPv4) header of the ICMP
packets after translation of a non-translatable IPv6 source address that
was present before L3 (v4->v6) translation.

Thanks,

Ramji

-----Original Message-----
From: Fred Baker (fred) 
Sent: Monday, April 09, 2012 9:41 PM
To: Randy Bush; [email-masked]
Cc: IPv6 Operations; Ron Bonica
Subject: Re: [v6ops] Reminder: draft-ietf-v6ops-ivi-icmp-address WGLC

Hmm

For some reason, I have been thinking of this prefix as only being used
in the ICMP message, not the IPv4 header.

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From: "Ramji Vaithianathan (rvaithia)" <[email-masked]>
Date: Mon, 9 Apr 2012 22:04:42 -0700

Inline,

Ramji

-----Original Message-----
From: Randy Bush [mailto:[email-masked]] 
Sent: Tuesday, April 10, 2012 10:22 AM
To: Ramji Vaithianathan (rvaithia)
Cc: Fred Baker (fred); [email-masked];
IPv6 Operations; Ron Bonica
Subject: Re: [v6ops] Reminder: draft-ietf-v6ops-ivi-icmp-address WGLC

RAMJI:  As I see, ICMP pkts are more then dataplane pkts, they do
indicate conditions such as Packet too big etc. - basically they
announce something.  Hence my question.

randy

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From: "Ramji Vaithianathan (rvaithia)" <[email-masked]>
Date: Tue, 10 Apr 2012 09:29:42 -0700

Hi Randy,

Let us look at a stateless NAT64 device, where the V6 translatable
addresses have an associated V4 address.  Basically the set of these V6
hosts will have an associated V4 prefix which will need to be advertised
on the V4 side of the network.  If the V4 side of the network is
internet, then the prefix associated with the V6 hosts should ideally be
advertised to all the routers in the internet, assuming all hosts in the
internet need to reach these V6 hosts with translatable addresses.  So
along with this prefix, we could potentially advertise the WKA as well -
basically instead of 1 prefix we have 2 of them.  Not sure if this will
create additional scalability issues.

Basically the V4 prefix associated with the V6 hosts and the wka both go
hand-in-hand.

Thanks,

Ramji

-----Original Message-----
From: Randy Bush [mailto:[email-masked]] 
Sent: Tuesday, April 10, 2012 10:45 AM
To: Ramji Vaithianathan (rvaithia)
Cc: IETF v6ops list
Subject: Re: [v6ops] Reminder: draft-ietf-v6ops-ivi-icmp-address WGLC

randy

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From: Randy Bush <[email-masked]>
Date: Wed, 11 Apr 2012 07:06:41 +0900

> create additional scalability issues.

perhaps we should be sure before we propose it?  i am not sure we
currently have an ipv4 prefix which is agreed to be globally present.
globally announced, aren't we all?  globally present, not so much.
globally present on all interfaces (where uprf is deployed), uh, ...

> Basically the V4 prefix associated with the V6 hosts and the wka both go

as i conjected from reading.

randy

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From: "Ramji Vaithianathan (rvaithia)" <[email-masked]>
Date: Thu, 12 Apr 2012 00:18:03 -0700

One example I could locate is the 6to4 prefix 192.88.99.0/24 which are
advertised by 6to4 routers to attract 6to4 traffic.

Thanks,

Ramji 

-----Original Message-----
From: Randy Bush [mailto:[email-masked]] 
Sent: Wednesday, April 11, 2012 3:37 AM
To: Ramji Vaithianathan (rvaithia)
Cc: IETF v6ops list
Subject: Re: [v6ops] Reminder: draft-ietf-v6ops-ivi-icmp-address WGLC

randy

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From: Randy Bush <[email-masked]>
Date: Thu, 12 Apr 2012 16:35:29 +0900

> One example I could locate is the 6to4 prefix 192.88.99.0/24 which
> are advertised by 6to4 routers to attract 6to4 traffic.

these are normal advertisements, and do not require configuration on
my routers (which are not otherwise connected to the 6to4 disaster).
and note how well the 6to4 disaster worked out.

your hack will require me to manually configure fake routes on all
interfaces of all my routers which use urpf.  not bloody likely.

randy