Subject: [lisp] Éric Vyncke's No Objection on draft-ietf-lisp-rfc6830bis-32: (with COMMENT)

From: Éric Vyncke via Datatracker <[email-masked]>
Date: Wed, 08 Jul 2020 13:36:28 -0700

Éric Vyncke has entered the following ballot position for
draft-ietf-lisp-rfc6830bis-32: No Objection

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COMMENT:
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Thank you for the work put into this document. This is really useful work and
the document is easy to read. I also appreciate the way the document handles
IPv6 and IPv4 at the same level. Selecting the UDP source port for ECMP based
on the inner 5-tuple is smart .

Please find below a couple of non-blocking COMMENTs.

I also support Martin Duke's DISCUSS on ICMP.

I hope that this helps to improve the document,

Regards,

-éric

== COMMENTS ==
I find the use of "prepending a LISP header" unusual. Why not using the word
"encapsulating" in a LISP packet? Or did I miss something? It may also slightly
be confusing when parts of the text use "prepending" and others use
"encapsulating".

-- Section 3 --
In "Egress Tunnel Router (ETR): ", is it required to be a 'server' to be able
to do "A server host can be the endpoint of a LISP tunnel as well.". I would
assume that any host can do it as well. In "Ingress Tunnel Router (ITR):" per
symmetry with ETR, can a server/client host also be the encapsulating endpoint
of a LISP tunnel?

-- Section 4 --
I STRONGLY suggest to remove the "telnet" example and keep only "SSH".

Cosmetic: suggest to add reference to SSH, BGP, SNMP, ...

-- Section 5.3 --
For "outer header", there is specific text for the IPv4 DF-bit, DSCP, ... but
what about specific IPv6 fields such as "flow label"?

Beside the convenience of making a bis document reflecting the original,
defining the "R" bit as reserved when at the same IESG telechat there is the
GPE document is really a missed opportunity IMHO.

Side comment (no need to reply), I am also puzzled why the outer DSCP is copied
to the inner DSCP on decapsulation.

-- Section 10 --
Is it on purpose that IPv6 is ignored in "This is typically done when a /32
address is configured on a loopback interface." ?

-- Section 12 --
What is meant by "flow" in "The Source port SHOULD be the same for all packets
belonging to the same flow." Probably worth defining it as packets with
identical 5-tuple ?

I also suggest not to limit the load-balancing text to LAG but also to any
topology where ECMP occurs.

Is there a reason why the hashing for LAG/load balancing is under the title of
"Routing Locator Hashing"? The UDP source port selection is vaguely related but
different than RLOC hashing.

-- Section 15 --
Unsure whether this performance section is still relevant in 2020, there are
many similar overlay techniques.

== NITS ==

-- Section 1 --
There are some repetitions in this section such as "[I-D.ietf-lisp-rfc6833bis]
specifies the LISP control plane. "

-- Section 3 --
When defining "anycast", I find that "An EID or RLOC can be an anycast address
in each of their own address spaces." is more a property of EID/RLOC than
adding anything to "anycast".