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-
- IETF STEERING GROUP (IESG)
-
- REPORT FROM THE TELECONFERENCE
-
- April 2nd, 1992
-
- Reported by: Greg Vaudreuil, IESG Secretary
-
- This report contains
-
- - Meeting Agenda
- - Meeting Attendees
- - Meeting Notes
-
- Please contact IESG Secretary Greg Vaudreuil for more information.
-
-
- ATTENDEES
- ---------
-
- Almquist, Philip / Consultant
- Borman, David / Cray Research
- Chiappa, Noel
- Crocker, Dave / TBO
- Coya, Steve / CNRI
- Davin, Chuck / MIT
- Gross, Philip / ANS
- Hinden, Robert / BBN
- Hobby, Russ / UC-DAVIS
- Piscitello, Dave/ Bellcore
- Stockman, Bernard / SUNET/NORDUnet
- Vaudreuil, Greg / CNRI
-
- Regrets
-
- Crocker, Steve / TIS
- Estrada, Susan / CERFnet
- Huizer, Erik / SURFnet
- Reynolds, Joyce / ISI
-
-
- AGENDA
- ------
-
- This teleconference was designated as a single topic conference to
- discuss and craft a plan for implementing an IETF Routing and
- Addressing development strategy.
-
-
- MINUTES
- -------
-
- The meeting began with a review of the timeframe the various
- solutions to the Routing and Addressing problems will be needed.
- For the ROAD effort, Phill Gross (and others) had investigated the
- growth rate of various Internet metrics, such as networks in the
- Merit Policy Routing Database, Assignement of IP network numbers, AS
- numbers, hosts, and DNS names. He was unable to send the detailed
- graphs, but did describe the growth trends.
-
- Based on the NSFnet Routing Database, the following timeframes were
- estimated:
-
- Class B Address exhaustion: ~ 2 Years ~30,000 configured Routes:
- ~ 2.5 Years IP address exhaustion: ~ 5 Years
-
- The rate of growth of the class B addresses in the Merit database
- appears to be slowing. It is not clear how this relates to the rate
- of address assignment. There is some indication that number of
- unconnected networks is rising.
-
- At this point the following amount of the address space is used.
-
- Assigned Available
-
- Class A 50 128
- Class b 7,500 16,384
- Class C 30,000 2,097,152
-
- The IESG discussed two of the sort term addressing proposals in terms
- of their time to deployment and useful life.
-
- C Sharp
-
- The C Sharp (C#) proposal calls for grouping the remaining C address
- space into a new class of networks with a larger host space This
- aggregation will not require hosts to recognize a change in class C
- addresses. No mask is necessary for a host to differentiate between
- the host and network portion of an address. Changes will be
- required to routers to recognize the new class of addresses. These
- changes are seen as a minor extensions to the current "classful"
- environment, and are seen as easy to add to current router
- software.
-
- This proposal does not provide for, nor does it prevent the
- aggregation of routing information and as such makes no improvement
- in the routing table size. C# "costs" a bit and reduces the
- effective number of class "C" networks by half.
-
- Classless Interdomain Routing (CIDR)
-
- The CIDR proposal calls for the elimination of the address class
- concept. By adding network address masks to interdomain routing
- protocols, networks can be assigned and aggregated efficiently to
- reduce the routing table size in transit network routers. This
- proposal allows both the aggregation of Class C networks into larger
- more useful networks and the splitting of class A networks into
- smaller, less wasteful networks.
-
- Because CIDR addresses require a address mask to understand which
- portions of an address are significant, it may either require
- changes to hosts to enable them to recognize address masks, or
- require careful engineering of network number assignment such that
- old-style hosts interpreting addresses as "classfull" won't get
- confused. The interpretation of the all 1's network broadcast is
- one such case.
-
- If CIDR is used solely for aggregation of existing classes of
- networks, no changes will be required for hosts. This reduces the
- utility of CIDR significantly in that Class "A" and Class "B"
- networks cannot be broken into smaller chunks. If not applied to
- Class "B" addresses CIDR will not help extend the life of the nearly
- exhausted Class "B" addresses.
-
- The Questions
-
- C# and CIDR are not exclusive. Both can be implemented
- simultaneously. The decision point lies in the timeframe the
- solution is expected to be used. If aggregation is needed in the
- immediate short term, there is no choice but CIDR Supernetting.
-
- A small survey of router vendors seems to indicate that current
- products with memory additions will handle up to 16,000 routes. In
- the near future, it is likely routers will be able to handle 35,000.
- Does this "more thrust" buy enough time to pursue the "long term"
- solution without requiring subnetting of Class A and B Via CIDR?
-
- How long will it take to implement and deploy the "real" solution,
- and will either c# and/or the CIDR supernetting last until then?
-
- ACTION: Gross, Chiappa -- Further investigate the anticipated
- capabilities of current and next generation routers with respect to
- routing table size.
-
-
- The IESG discussed available mechanisms and what problems they addressed.
-
- Solutions Matrix
-
- | Rout | Class B | IP Exhaustion
- -------------+---------+---------+-------------
- C-Sharp | | x |
- -------------+---------+---------+-------------
- CIDR | x | x |
- -------------+---------+---------+-------------
- More Thrust | x | |
- -------------+---------+---------+-------------
- Recycling | | x |
- -------------+---------+---------+-------------
- IP encaps x | x | x
- -------------+---------+---------+-------------
- ISO encaps | x | x | x
- -------------+---------+---------+-------------
- Simple CLNP | x | x | x
- -------------+---------+---------+-------------
-
- Expected Timeframes
-
- | : : :
- More Thrust |@@@@@ : : :
- | : : :
- Recycling |@@@@ : : :
- | : : :
- Class C-Sharp | @@@@@: : :
- | : : :
- CIDR | @@@@@@@@@@@@@@@@ : :
- | : : :
- IP Encaps | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ :
- | : : :
- Simple CLNP | : @@@@@@@@@@@@@@@@@@@@@@@@@@@@
- | : : :
- CLNP Encaps | : @@@@@@@@@@@@@@@@@@@@@@
- | : : :
- +-------+---------------+---------------+----------- Time
- Class B IP Need
- Exhaustion Exhaustion 10**9
- nets
-
- Work Plan
-
- There are currently several efforts at extending protocols for CIDR
- Supernetting underway. BGP version 4 is being defined in the BGP
- working group. Dual IDRP is being developed, and Interdomain Policy
- Routing is defined to support classless routing. The IESG
- encourages this work to continue.
-
- IP encapsulation, ISO encapsulation (one method of implementing
- CNAT), and CIDR all require that IP addresses be assigned in
- "blocks" to facilitate aggregation. The IESG recognized that each of
- these approaches required an IP addressing plan that supported
- aggregation. At least the following need to be part of developing an
- IP addressing plan: the IETF Internet Area, IETF Routing Area, IETF
- Operational Requirements, FEPG, and IEPG.
-
- Action: Gross -- Develop a plan for coordinating the development of an
- address assignment strategy. Work with Chiappa, Almquist, and Hinden
- in establishing the appropriate liaison.
-
- The IESG did not recommend between CIDR and C# for sort term address
- extensions at this meeting. However, there was a strong feeling
- that activities needed to begin immediately, and that the IESG
- needed to make recommendations on a work plan soon. The IESG asked
- Philip Almquist to draft a strawman recommended work plan for IESG
- to consider as its position.
-
- ACTION: Almquist -- Using the work of the ROAD working group, and the
- minutes of this meeting, draft a position for IESG review.
-
- The IESG did not have adequate information to discuss the three long
- term proposals, IP encapsulation, ISO encapsulation (CNAT), and
- Simple CLNP.
-
-