Operational Experience with IPv6

1
Operational Experience with IPv6

• Bob FinkLBNL/ESnet
• NANOG19
• Albuquerque, NM
• 11-13 June 2000

2
This session

• Brief talks on our IPv6 experiences
• Bob Fink 6bone, Esnet, 6tap
• Greg Miller MCI WorldCom, vBNS
• Bill Maton CRC, Canarie
• Rob Rockell Sprint
• Sean Mentzer Qwest
• Panel QA session
• Bob Fink moderator

3
The 6bone

• First IPv6 packets in mid-1996 between a few
  sites in Europe, Japan and US
• started with tunnels (v6 encapsulated in v4),
  now moving to more native links
• primary goal to test implementations, their
  interoperability, that the standards work and
  provide feedback to the IETF
• and to get early operational experience

4
6bone today (as of 5Jun00)

• Now in 46 countries AR, AU, AT, BE, BR, BG, CM,
  CA, CN, CZ, DK, EE, FI, FR, DE, GR, HK, HU, IN,
  IE, IT, JP, KZ, KR, LT, MY, MX, NL, NZ, NO, PL,
  PT, RO, RU, SG, SK, SI, ZA, ES, SE, CH, TW, UA,
  GB, US, UY
• 571 networks/sites 135 US, 66 DE, 38 JP, 28 FR,
  28 GB(UK), 20 SE, 10 CN, 9 RU, 4 MX etc.
• 68 pTLAs most recent addition UUNET 27Apr00

5
Primary lessons

• Besides implementations and standards issues that
  come up and are corrected...
• overall IPv6 does act and work like IPv4
• Though we started with static routes, IDRPv6 and
  RIPng, everyone wanted BGP4 and we moved to it
  fast
• It has not been hard to setup, manage, maintain
  and operate IPv6 nets (again, it is like IPv4
  funny thing -) Ill leave it to other panel
  members for more

6
6bone (IPv6) Registry

• From the start of the 6bone project a registry
  was used to keep track of at least the top tier
  networks, their peerings and prefix allocations
• RIPE-style db developed by David Kessens then of
  ISI, now of Nokia
• He added ipv6-site and inet6num objects
• Has proven invaluable for net reports,
  measurement, management and peering

7
Network Tools for tracking problems

• Merit IPv6 Routing report (daily)
• Size of 6Bone Routing Table
• BGP4 Traffic Summary
• Unknown AS Numbers
• Unknown Prefixes
• Poorly Aggregated Announcements
• Prefixes from Different Origin AS
• Most Active Prefixes

8
Contd.

• CSELT (Italy) BGP4 Operational report using
  Aspath-tree tool
• Graphic display of BGP4 routing entries
• Odd routes reports
• invalid unaggregated prefixes
• Routing Stability Report
• Routing History graphs

9
Example CSELT routing history graph
10
Contd.

• SLAC PingER services uses a modified IPv6 ping
  service to probe and report on path reliability
• data is databased and historically accessibel
  hour, day, month
• TCP Throughput
• Zero packet loss frequency
• PING unpredictability unreachability
• Packet loss
• PING response history

11
Automated mapping services

• Among other things the 6bone registry is used
  for, it can help generates pictures of the 6bone
  pTLA backbone network peering relationships
• Lancaster Univ. have done much of this work

12

13
6bone future

• Will stay in place until no longer needed
• excellent place for an ISP to get early
  experience before going into production
• probably not the best way to support transition
  to IPv6, but if needed for this it will stay in
  place
• expect that the 6to4 Transition Mechanism and
  native IPv6 support by your IPv4 ISP is best to
  support transition

14
Aggregatable Unicast Addressing
3
13
24
16
64
8
R s r v
TLA
NLA
SLA
Interface ID
001
48-bit Public Topology Routing Prefix
80-bit end-site specific usage ISP cannot change
this
TLA Top-Level Aggregation ID - are assigned
to ISPs and Exchanges that act in a default-free
way with a routing table entry for every active
TLA ID (helps constrain the routing
complexity) Rsrv Reserved for either TLA or NLA
expansion NLA Next Level Aggregation ID - are
assigned by TLAs to create a multi-level
hierarchy underneath it as the ISP chooses
(i.e., multiple NLA levels allow more ISPs and
then the end site) SLA Site Level Aggregation
IDs are used to create local addressing hierarchy
(e.g., a flat subnet space allowing 65K
subnets) Interface ID unique ID on subnet
(typically formed automatically)
15
Current TLA assignments

• TESTING (3FFE/16) assigned for IETF ngtrans
  use by RFC 2471 for use by 6bone project -
  currently used for pTLAs
• Sub-TLAs (2001/16) assigned to RIRs for
  allocation of Sub-TLAs
• 6to4 prefix (2002/16) assigned for use by the
  Connection of IPv6 Domains via IPv4 Clouds
  without Explicit Tunnels spec (soon to be at PS)
  to hold the IPv4 tunnel endpoint address in the
  32-bit Rsrv NLA fields

16
6bone (IPv6 testbed) pTLAs
3
13
24 or 20
16
64
8 or 12
TLA 0x1FFE
pseudo TLA
NLA
SLA
Interface ID
001

• The 6bone uses a variation of this concept called
  pseudo-TLAs (pTLAs)3FFE0000/24 to
  3FFE7F00/24 old 8-bit pTLA space3FFE8000/2
  8 to 3FFEFFF0/28 new 12-bit pTLA space

17
Sub-TLAs
3
13
13
16
64
13
6
TLA 0xOOO1
Sub TLA
R s r v
NLA
SLA
Interface ID
001

• To assist in the slow start of TLA assignment, a
  Sub-TLA was defined which allows the
  international address registries to slow start
  TLA usage by just assigning a single TLA for
  Sub-TLAs
• an ISP must demonstrate high usage of its Sub-TLA
  space before qualifying for a TLA or another
  Sub-TLA
• in practice, the RIRs are slow starting the /29
  space by only assigning /35s to start again, a
  high usage required before getting more of the
  /29

18
Sub-TLA usage today

• RIRs started to assign in July 1999,34 assigned
  to date
• APNIC (13 Sub-TLAs assigned)
• ARIN (4 Sub-TLAs assigned)
• RIPE-NCC (17 Sub-TLAs assigned)

19
6to4

• Specifies the 16-bit TLA prefix 2002/16as a
  6to4 flag indicating that the 32-bit sized NLA
  below it carries an IPv4 Tunnel Endpoint Address
  of the sites egress router

3
13
16
64
32
TLA 0x002
IPv4 TEA
SLA
Interface ID
001
20
ESnet

• ESnet serves the network needs of the US Energy
  Research national labs, which is now IPv4 (just
  turned off DecNET -)
• early participant in 6bone using tunnels, then
  moved to native IPv6 in 1999
• operates a Cisco IPv6 EFT router mesh over the
  ESnet ATM cloud
• as of July 1999 ESnet operational staff handles
  IPv6 peering and routing in parallel with, and
  the same as IPv4

21
Application usage

• For now usage limited to early application
  conversion (to the IPv6 API) and demonstration
  that high-profile scientific apps run over IPv6
  the same as IPv4
• also a significant network measurement activity
  in place
• software (versus hardware) IPv6 packet forwarding
  ok for most early purposes, but it does get in
  way of the high-speed scientific apps were
  waiting too!

22
The 6TAP

• To facilitate peering of native IPv6 providers,
  ESnet and Canarie/Viagenie formed the 6tap IPv6
  routing service in August 1999 at the
  StarTAP/ChicagoNAP
• Working with Sun and Merit to get early an early
  IPv6 Route Server up
• Working with early IPv6 ISPs to establish BGP4
  routing policies and practices
• A 6to4 Relay service and a Site-Tunnel-Server
  service will also be provided soon

23
What next

• Waiting for production hardware-based routers so
  we can operate v4 v6 in same routers
• and of course for production IPv6 host code to
  become widely available
• meanwhile, it is quite cheap and easy to put up
  some IPv6 routing to gain knowledge and early
  operational experience

24
Thanks for listening

• Pointer to everything IPv6
• www.6bone.net
• Questions on anything IPv6 (dont worry, Ill
  forward you to the right place)
• fink_at_es.net