Locator/ID Separation Protocol Alternative Logical Topology (LISP+ALT)
RFC 6836
Yes
No Objection
Note: This ballot was opened for revision 10 and is now closed.
(Jari Arkko; former steering group member) Yes
(Adrian Farrel; former steering group member) (was Discuss) No Objection
I picked out the same sentence as several others... EID-prefixes are expected to be allocated to a LISP site by Internet Registries. ...but I wondered whether you were saying something less alarming than they interpretted (for example, that the addresses are not from a private space). In any case, clarification will surely help. --- Abstract I can't parse... Termed the Alternative Logical Topology (ALT), the index is built as an overlay network on the public Internet using the Border Gateway Protocol (BGP) and the Generic Routing Encapsulation (GRE). The "index" is termed the ALT? The "index" is built as a network? Maybe s/index/distributed index system/ ?
(Dan Romascanu; former steering group member) No Objection
(Gonzalo Camarillo; former steering group member) No Objection
(Pete Resnick; former steering group member) No Objection
(Peter Saint-Andre; former steering group member) No Objection
(Ralph Droms; former steering group member) (was Discuss) No Objection
What does this phrase from the definition of EID-prefix mean:
EID-
prefixes are routed on the ALT (not on the global Internet)
Perhaps "information about EID-prefixes is exchanged among ALT
routers through BGP" or "Map-Requests are routed through the ALT to
the ETR that owns the requested EID-prefix"?
From section 4:
An ITR uses the ALT to learn the best path for forwarding an ALT
Datagram destined to a particular EID-prefix.
Really? Does the ITR really learn the best path? I thought the
forwarding was all done transparently by the ALT routers.
In section 6.1, I think LISP+ALT MUST "use newly-assigned AS numbers
that are unrelated to the ASNs used by the global routing system."
Presumably the lisp WG or some appropriate authority on behalf of the
experiment will formally request the ASNs from IANA?
From section 7:
The ALT BGP peering topology should be arranged in a tree-like
fashion (with some meshiness), with redundancy to deal with node and
link failures.
I would need some additional detail if I were to participate in the
experiment. I thought the ALT routers formed a mesh of sorts.
Does "tree-like fashion (with some meshiness)" mean a tree topology
within a LISP site and a mesh among sites?
(Robert Sparks; former steering group member) (was Discuss) No Objection
(Ron Bonica; former steering group member) (was Discuss) No Objection
(Russ Housley; former steering group member) No Objection
(Sean Turner; former steering group member) (was Discuss) No Objection
(Stephen Farrell; former steering group member) (was Discuss) No Objection
(Stewart Bryant; former steering group member) No Objection
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Using these proven protocols,
the ALT can be built and deployed relatively quickly without any
changes to the existing routing infrastructure.
SB> Whilst this may be true the text sounds like it fell off the
SB> back of a marketing slide.
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Legacy Internet: The portion of the Internet which does not run
LISP and does not participate in LISP+ALT.
SB> A rather pejorative term. Particularly as LISP is an
SB> experimental protocol.
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3.3. Caveats on the use of Data Probes
It is worth noting that there has been a great deal of discussion and
controversy about whether Data Probes are a good idea. On the one
hand, using them offers a method of avoiding the "first packet drop"
problem when an ITR does not have a mapping for a particular EID-
prefix. On the other hand, forwarding data packets on the ALT would
require that it either be engineered to support relatively high
traffic rates, which is not generally feasible for a tunneled
network, or that it be carefully designed to aggressively rate-limit
traffic to avoid congestion or DoS attacks. There may also be issues
caused by different latency or other performance characteristics
between the ALT path taken by an initial Data Probe and the
"Internet" path taken by subsequent packets on the same flow once a
mapping is in place on an ITR. For these reasons, the use of Data
Probes is not recommended at this time; they should only be
originated an ITR when explicitly configured to do so and such
configuration should only be enabled when performing experiments
intended to test the viability of using Data Probes.
SB> This text looks like it needs to be in the main LISP spec.
SB> There also needs to be text discussion the impact of the
SB> cache system on connectionless flows.
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SB> There does not seem to be a definition of "PI"
(Wesley Eddy; former steering group member) No Objection