Brian,
On Mon, Oct 10, 2022 at 10:53 PM Brian E Carpenter
<brian.e.carpen...@gmail.com> wrote:
Dirk,
I'm not picking on your message particularly, because the comment
below
could be made on many of the messages on this thread:
On 11-Oct-22 04:51, Dirk Steinberg wrote:
> Well, an IPv6 packet with an SRH first of all is a legal IPv6
packet.
>
> Dropping of IP packets which are not malformed by transit domains
> based on arbitrary local policies is a very bad thing IMHO.
The operators who do so, which are in fact rarely transit providers,
but either ISPs or enterprise operators, or even domestic users who
don't know that their CPE is doing it, don't care about Internet
transparency or about some interpretations of the end-to-end
principle.
They care about their interpretation of security and anti-penetration.
The reality is, and has been for most of the last 25 years or longer,
that some packets are systematically dropped for this reason. Anyone
who thinks this is untrue should perhaps start with RFC7872, RFC9098,
RFC9288 and draft-elkins-v6ops-eh-deepdive-fw.
As long as it's done by a "leaf" domain (end user CPE, enterprise
network, ...)
we are in agreement, as I already said explicitly. I do understand their
security and anti-penetration concerns and I am clearly aware that
this has been done basically forever ("firewalling").
At the ingress to my own network I will certainly implement similar
policies for myself to protect my local network.
However, my ISP should be providing IP transit services for the
packets I send
and receive and I do not want him to decide what is good or bad for me
and
implement some filtering based on his interpretation of "good" and "bad".
That is up to me. I do not subscribe to "supervised thinking".
The same reasoning of course also applies to upstream transit network
operators.
Also, the concept of "limited domains" that some people love to hate
isn't a proposal, it's an observation of running code.
Sure. But I might be running my own "limited domain" which could be
spread across different geographical locations and I do not wish anyone
to interfere with this unless he is part of that limited domain.
Cheers
Dirk
Regards
Brian
>
> If many operators adopt such practices based on their very own local
> policies we will end up with a network which is NOT the Internet
anymore,
> but rather some unreliable internetwork where it becomes
unpredictable
> if packets can be sent end-to-end or not.
>
> This is NOT my understanding of the Internet.
>
> I strongly object to transit domains dropping packets based on
> arbitrary local policies regarding arbitrary extension headers.
>
> The presence of an SRH for example has NO security or other
> negative implication for any transit domain. Note that the keyword
> here is TRANSIT. If the IPv6 DA is within that operators domain
> things are different, but then the operator will want to filter
at his
> domain ingress based on the IPv6 destination address being from
> his (protected) address space. Such filtering is justified.
>
> Cheers
> Dirk
>
> On Mon, Oct 10, 2022 at 6:32 PM David Farmer
<farmer=40umn....@dmarc.ietf.org
<mailto:40umn....@dmarc.ietf.org>> wrote:
>
> Well, I'd agree it is contrary to several RFCs, but illegal
is way too strong of a word and implies somehow that RFCs gained
the force of law that I'm not aware they have.
>
> Furthermore, declaring the dropping of packets as evil is
additional unnecessary hyperbole.
>
> Finally, if we are going to go after people for committing
immoral acts against packets, dropping them because of SRH headers
is fairly low on my list.
>
> Thanks
>
> On Mon, Oct 10, 2022 at 10:05 AM Robert Raszuk
<rob...@raszuk.net <mailto:rob...@raszuk.net>> wrote:
>
> David,
>
> No, that is not what I am saying. I am saying that the
concept of limited domains is very loosely defined in rfc8799 and
using it as a base to drop packets which contain SRH is not right.
>
> For example are my enterprise sites interconnected with
SD-WAN a limited domain - surely is for me even if I use vanilla
IPv6 Interconnect to talk between them.
>
> And let's not worry about such sites' security ... This
is a completely different topic. Let's agree that dropping IPv6
packets somewhere in transit only because they contain specific
extension header is illegal.
>
> Thx,
> R.
>
>
>
>
> On Mon, Oct 10, 2022 at 4:56 PM David Farmer
<far...@umn.edu <mailto:far...@umn.edu>> wrote:
>
> If you are saying the concept of Limited Domains
does not apply to SRH since it isn't an IETF consensus document,
then I believe that calls the consensus for SRH into serious
question. Furthermore, if the SRH consensus is questionable, the
idea that operators might filter it shouldn't be surprising.
>
> Thanks
>
> On Mon, Oct 10, 2022 at 9:24 AM Robert Raszuk
<rob...@raszuk.net <mailto:rob...@raszuk.net>> wrote:
>
> Joel,
>
> Am I wrong understanding that definition of
"limited domain" was never approved by any formal IETF process ?
>
> If so do you really think we should be bounded
on something which has been defined outside of IETF ?
>
> Cheers,
> Robert
>
> On Mon, Oct 10, 2022 at 4:03 PM Joel Halpern
<jmh.dir...@joelhalpern.com <mailto:jmh.dir...@joelhalpern.com>>
wrote:
>
> SRH was explicitly defined for use in
limited domains. That is why I think dropping it is acceptable.
Certainly not required, but permitted. The closest equivalent is
NSH, which is also defined for limited domains. In my personal
opinion (not speaking for the SFC working group) I think it would
be legitimate for a domain, particularly one that is using NSH, to
drop packets where the IP carried protocol is NSH. (I would
prefer that they block only packets to their domain with carried
protocol of NSH, but that is up to the operator.)
>
> You have said that you consider the limited
domain requirement to be wrong and irrelevant. Whether you agree
with it or not, it is in the RFC. Operators may reasonably act on
that.
>
> Yours,
>
> Joel
>
> On 10/10/2022 9:59 AM, Robert Raszuk wrote:
>> > it seems acceptable to block all packets
with SRH
>>
>> And such statements you are making are
exactly my point.
>>
>> Just curious - Is there any other
extension header type subject to being a good enough reason to
drop packets at any transit node in IPv6 ?
>>
>> Thx,
>> R.
>>
>> On Mon, Oct 10, 2022 at 3:53 PM Joel
Halpern <jmh.dir...@joelhalpern.com
<mailto:jmh.dir...@joelhalpern.com>> wrote:
>>
>> Protection from leaking inwards is
required by the RFCs as far as I know.
>>
>> Note that there are multiple ways to
apply such protection. It is sufficient for the domain only to
block packets addressed to its own SID prefixes. If the domain is
using SRv6 without compression or reduction, it seems acceptable
to block all packets with SRH. After all, they should not be
occurring. But we do not tell operators how to perform the
filtering. It is up to them what they do.
>>
>> Yours,
>>
>> Joel
>>
>
--------------------------------------------------------------------
> IETF IPv6 working group mailing list
> i...@ietf.org <mailto:i...@ietf.org>
> Administrative Requests:
https://www.ietf.org/mailman/listinfo/ipv6
<https://www.ietf.org/mailman/listinfo/ipv6>
>
--------------------------------------------------------------------
>
>
>
> --
> ===============================================
> David Farmer Email:far...@umn.edu
<mailto:email%3afar...@umn.edu> <mailto:email%3afar...@umn.edu
<mailto:email%253afar...@umn.edu>>
> Networking & Telecommunication Services
> Office of Information Technology
> University of Minnesota
> 2218 University Ave SE Phone: 612-626-0815
> Minneapolis, MN 55414-3029 Cell: 612-812-9952
> ===============================================
>
>
>
> --
> ===============================================
> David Farmer Email:far...@umn.edu
<mailto:email%3afar...@umn.edu> <mailto:email%3afar...@umn.edu
<mailto:email%253afar...@umn.edu>>
> Networking & Telecommunication Services
> Office of Information Technology
> University of Minnesota
> 2218 University Ave SE Phone: 612-626-0815
> Minneapolis, MN 55414-3029 Cell: 612-812-9952
> ===============================================
>
--------------------------------------------------------------------
> IETF IPv6 working group mailing list
> i...@ietf.org <mailto:i...@ietf.org>
> Administrative Requests:
https://www.ietf.org/mailman/listinfo/ipv6
<https://www.ietf.org/mailman/listinfo/ipv6>
>
--------------------------------------------------------------------
>
>
> --------------------------------------------------------------------
> IETF IPv6 working group mailing list
> i...@ietf.org
> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> --------------------------------------------------------------------
