Transcript LISP BOF Update draft-farinacci-lisp-08.txt Dino Farinacci, Dave Meyer, Vince Fuller, Darrel Lewis, Scott Brim, Dave Oran IETF Dublin - July 2008

LISP BOF Update
draft-farinacci-lisp-08.txt
Dino Farinacci, Dave Meyer, Vince Fuller, Darrel Lewis,
Scott Brim, Dave Oran
IETF Dublin - July 2008
Agenda
•
•
•
•
•
Overview of LISP
Changing Mapping Database Entries
Support for Mixed Locators
Spec changes between -06 to -08
Open Issues
LISP BOF Update
IETF Dublin - July 2008
Slide 2
LISP Internet Drafts
draft-farinacci-lisp-08.txt
draft-fuller-lisp-alt-02.txt
draft-lewis-lisp-interworking-01.txt
draft-farinacci-lisp-multicast-00.txt
draft-meyer-lisp-eid-block-01.txt
draft-mathy-lisp-dht-00.txt
draft-iannone-openlisp-implementation-01.txt
draft-brim-lisp-analysis-00.txt
draft-meyer-lisp-cons-04.txt
draft-lear-lisp-nerd-04.txt
draft-curran-lisp-emacs-00.txt
LISP BOF Update
IETF Dublin - July 2008
Slide 3
LISP Problem Statement
• Improve site multi-homing
– Allow site control ingress traffic paths
– Avoid renumbering by providing for portable addresses
– Do it with lower OpEx
• Improve Traffic Engineering for ISPs
– Use level of indirection rather than more specific injection
•
•
•
•
Reduce core routers routing table size
Aid in IPv4 to IPv6 transition
Provide Server Load Balancing in Data Center
Some form of mobility
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Slide 4
LISP Conceptually
• IPv4 and IPv6 addresses have overloaded semantics
• LISP separates Location from ID
• Introduces 2 address spaces:
– Endpoint IDs (EIDs)
– Routing Locators (RLOCs)
• Use 32-bit EIDs for IPv4 from registry allocation
• Use 128-bit EIDs for IPv6 from registry allocation
• Use topological addresses for Locators from ISP
address block allocations
LISP BOF Update
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Slide 5
Multi-Level Addressing
Provider A
10.0.0.0/8
Provider B
11.0.0.0/8
RLOCs used in the core
Mapping Database Entry:
R1
R2
S
1.0.0.0/8 -> (10.0.0.1, 11.0.0.1)
EIDs are inside of sites
1.0.0.0/8
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Slide 6
LISP is Map-n-Encap
Host Stack:
supplies EIDs
Mapping Entry:
EID-prefix: 2.0.0.0/8
Locator-set (RLOCs):
12.0.0.2, priority: 1, weight: 50
13.0.0.2, priority: 1, weight: 50
LISP Router:
supplies RLOCs
by adding new
header
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Slide 7
LISP Solution Space
• LISP - Locator/ID Separation Protocol
–
–
–
–
–
–
Network-based solution
No changes to hosts whatsoever
No new addressing changes to site devices
Very few configuration file changes
Imperative to be incrementally deployable
Address family agnostic
LISP BOF Update
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Slide 8
Unicast Packet Forwarding
PI EID-prefix 1.0.0.0/8
ITR
Provider A
10.0.0.0/8
S1
S
PI EID-prefix 2.0.0.0/8
ETR
Provider X
12.0.0.0/8
D1
ITR
S2
Provider B
11.0.0.0/8
D2
Provider Y
13.0.0.0/8
1.0.0.1 -> 2.0.0.2
1.0.0.1 -> 2.0.0.2
11.0.0.1 -> 12.0.0.2
DNS entry:
D.abc.com
D
ETR
11.0.0.1 -> 12.0.0.2
1.0.0.1 -> 2.0.0.2
A 2.0.0.2
EID-prefix: 2.0.0.0/8
Mapping
Legend:
EIDs -> Green
Locators -> Red
LISP BOF Update
1.0.0.1 -> 2.0.0.2
Entry
Locator-set:
12.0.0.2, priority: 1, weight: 50 (D1)
13.0.0.2, priority: 1, weight: 50 (D2)
IETF Dublin - July 2008
Policy controlled
by destination site
Slide 9
Locator Reachability
PI EID-prefix 2.0.0.0/8
D2 D2
S
S
ITR
Provider A
10.0.0.0/8
S1
Provider X
12.0.0.0/8
X X
ITR
S
0003 ETR
D1
D
X
D
ETR
S2
Provider B
11.0.0.0/8
D2
Provider Y
13.0.0.0/8
D2 D2
D
0002
0003
loc-reach-bits:
0x0000 0003
EID-prefix: 2.0.0.0/8
Mapping
Entry
Legend:
EIDs -> Green
Locators -> Red
LISP BOF Update
Locator-set:
12.0.0.2, priority: 1, weight: 50 (D1)
-> ordinal 0
13.0.0.2, priority: 1, weight: 50 (D2)
-> ordinal 1
IETF Dublin - July 2008
7654 3210
b’xxxx xxxx’
Slide 10
Changing Mapping Entries
• A “change” is defined to be:
– Adding a locator to a locator-set
– Changing an existing locator’s priority or weight (for
either unicast or multicast)
– Removing a locator from a locator-set
• Adding entries is simple
– Append to the end, new loc-reach-bit allocated and set
– Old cachers ignore loc-reach-bit set for non-existent
locator
– New cachers use new locator-set and all loc-reach-bits
LISP BOF Update
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Slide 11
Changing Mapping Entries
• Removing a locator is done by:
– Set loc-reach-bit to 0
– “Zero-fill” address in slot, set priority 255
– Old cachers have non-zero slot but don’t use
locator since loc-reach-bit 0
– New cachers see empty 255 slot and don’t use
• Changing priority or weights
– Use Clock Sweep or SMRs
LISP BOF Update
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Slide 12
Changing Mapping Entries
EID-prefix: 153.16.1.0/24, loc-reach-bits: 0x000f, locator-set:
1.0.0.1, priority: 1, weight: 25
2.0.0.2, priority: 1, weight: 25
3.0.0.3, priority: 1, weight: 25
4.0.0.4, priority: 1, weight: 25
Changed providers: 2.0.0.2 disconnect and 5.0.0.5 connects
EID-prefix: 153.16.1.0/24, loc-reach-bits: 0x001d, locator-set:
delete
1.0.0.1, priority: 1, weight: 25
0.0.0.0, priority: 255, weight: 25
3.0.0.3, priority: 1, weight: 25
add
Over time compaction may be required
to get loc-reach-bits back!
4.0.0.4, priority: 1, weight: 25
5.0.0.5, priority: 1, weight: 25
LISP BOF Update
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Slide 13
Locator-Set Compaction Changes
• Operational Mechanism
– Clock Sweep
• Protocol Mechanism
– Solicit Map-Requests (SMRs)
LISP BOF Update
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Slide 14
Clock Sweep
Send Map-Replies with
old mapping with TTL = 1 hour
time
Send Map-Replies with
old mapping with TTL = 1 minute
Send Map-Replies with
new mapping with TTL = 24 hours
(not to scale)
24 hours
Start the
change process
1 hour
TTL = 24 cachers
time out,
TTL = 1 cachers have
been timing out
each hour
1 minute
Change process
ends
TTL = 1 hour cachers
time out,
TTL = 1 minute cachers have
been timing out
each minute
LISP BOF Update
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Slide 15
Solicit Map-Requests (SMRs)
• Used when a site needs compaction
• Sites solicit Map-Requests from active sites
– SMR-bit is in encapsulated LISP header
– ITRs rate limit to control the number and rate of Map-Requests
they want to receive
• Remote ITRs rate-limit Map-Requests until they get a MapReply with the new database mapping entry
• Nonce from SMR copied to Map-Request copied to Map-Reply
• Map-Request can be sent either on ALT or underlying network
• Local ITR keeps track of which site has new versus old
mappings for appropriate loc-reach-bit setting
• No map versioning required
– Recommendation is to have only one outstanding change
LISP BOF Update
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Slide 16
Mixed Locators
• What are mixed locators?
dr22# sh ip lisp map-cache
LISP IP Mapping Cache for VRF "default" - 1 entries
240.23.0.0/24, uptime: 00:00:14, state: complete, last modified: 00:00:14
1.22.23.23, uptime: 00:00:14, state: up, priority/weight: 1/50
11.22.23.23, uptime: 00:00:14, state: up, priority/weight: 1/50
dr22# sh ipv6 lisp map-cache
LISP IPv6 Mapping Cache for VRF "default" - 1 entries
0240:0023::/32, uptime: 00:22:00, state: complete, last modified: 00:22:00
dfdf:2223::0023, uptime: 00:22:00, state: up, priority/weight: 1/33
1.22.23.23, uptime: 00:22:00, state: up, priority/weight: 1/33
11.22.23.23, uptime: 00:22:00, state: up, priority/weight: 1/33
Mixed locator-set
LISP BOF Update
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Slide 17
Mixed Locators
• LISP-ALT needs to be dual-stack
• Data Probes and Map-Requests are
homogenous
– EID needs to be in destination address
• Map-Reply is sent on the underlying
network
– Therefore underlying has to be dual-stack
– But IPv6 is not ubiquitous so we need IPv4 MapReplies for IPv6 Data Probes or Map-Requests
LISP BOF Update
IETF Dublin - July 2008
Slide 18
Mixed Locators - Some Cautions
• Locator Reachability tells you that xTR is up
– Doesn’t tell you what the AF path is from you to the ETR
• Hashing considerations
– Destination EID hashes to AF RLOC
– Source RLOC must be same AF
• Setting priorities for a mixed locator-set is difficult
– Because you don’t know AF path for requesting source site
– Better to have “crossed sets”
• IPv4 EIDs -> all IPv6 RLOCs (China and Japan deployments)
• IPv6 EIDs -> all IPv4 RLOCs (US deployments)
LISP BOF Update
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Slide 19
Mixed Locators are Useful
ITR
S1
Provider A
10.0.0.0/8
Provider X
12.0.0.0/8
ITR
S
IPv6-only
S2
ETR
D1
D
ETR
D2
Provider B
11.0.0.0/8
IPv6-only
Provider Y
13.0.0.0/8
IPv4 Internet
Legend:
EIDs -> Green
Locators -> Red
LISP BOF Update
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Slide 20
Mixed Locators are Useful
IPv4
S
ITR
S1
Provider A
10.0.0.0/8
ETR
Provider X
12.0.0.0/8
D1
ITR
IPv6-only
S2
ETR
Provider B
11.0.0.0/8
D2
Provider Y
13.0.0.0/8
13::/16
D
Dual-stack
S
Partly Dual-Stack
Internet
E2
E1
Legend:
D
EIDs -> Green
Locators -> Red
LISP BOF Update
Dual-stack
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Slide 21
Spec Diffs between -06 to -08
• Lots of clarification text from many reviewers
• Clearly specify only 2 LISP headers can be prepended
– First one for Loc/ID split by CPE router
– Second one for TE by ISP router
• Add SMR-bit to data header and Map-Request
– Steal a loc-reach-bit
• Specify how to select a source UDP port number
LISP BOF Update
IETF Dublin - July 2008
Slide 22
Spec Diffs between -06 to -08
• Added mpriority and mweight
– So locator selection can be different for unicast or multicast
flows
• Updated section on LISP-Multicast to summarize
details in draft-farinacci-lisp-multicast-00.txt
• When ITR receives ICMP unreachable
– It may originate one to the source host inside of its site
• Add section on locator hashing for equal-priority
locators
• Add sections for Clock Sweep and SMRs
• Updated milestone section
LISP BOF Update
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Slide 23
Rough Set of Milestones
1.
This draft will be the draft for interoperable implementations to
code against. Interoperable implementations will be ready summer
of 2008.
2.
Continue pilot deployment summer of 2008 using LISP-ALT as the
database mapping mechanism.
3.
Continue prototyping other database lookup schemes, be it DNS,
DHTs, CONS, ALT, NERD, or other mechanisms.
4.
Implement the LISP Multicast draft [MLISP].
5.
Research more on how policy affects what gets returned in a MapReply from an ETR.
6.
Continue to experiment with mixed locator-sets to understand how
LISP can help the IPv4 to IPv6 transition.
LISP BOF Update
IETF Dublin - July 2008
Slide 24
Accomplishments
1.
A unit- and system-tested software switching implementation has
been completed on cisco NX-OS for this draft for both IPv4 and
IPv6 EIDs using a mixed locator-set of IPv4 and IPv6 locators.
2.
A unit- and system-tested software switching implementation on
cisco NX-OS has been completed for draft for [ALT].
3.
A unit- and system-tested software switching implementation on
cisco NX-OS has been completed for draft [INTERWORK]. Support
for IPv4 translation is provided and PTR support for IPv4 and
IPv6 is provided.
4.
The cisco NX-OS implementation supports an experimental mechanism
for slow mobility.
5.
Dave Meyer, Vince Fuller, Darrel Lewis, Greg Shepherd, and Andrew
Partan continue to test all the features described above on a
dual-stack infrastructure.
6.
Darrel Lewis and Dave Meyer have deployed both LISP translation
and LISP PTR support in the pilot network. Point your browser to
http://www.lisp4.net to see translation happening in action so
your non-LISP site can access a web server in a LISP site.
7.
Soon http://www.lisp6.net will work where your IPv6 LISP site can
talk to a IPv6 web server in a LISP site by using mixed addresfamily based locators.
8.
An public domain implementation of LISP is underway.
[OPENLISP] for details.
9.
A cisco IOS implementation is underway which currently supports
IPv4 encapsulation and decapsulation features.
LISP BOF Update
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See
Slide 25
Open Issues
• Experiment with more-specific mappings and policy-based MapReply priority changing
• ISP resident TE-xTR functionality with another “multi-level LISP”
hierarchy
• Firm up details on LISP-Multicast
• LISP can do some form of mobility
– More specific state only at edges in xTRs
– Can we extend it for secure and graceful handoff
• Continue prototyping ideas and deploying on pilot network
• Interoperability testing of NX-OS, IOS, and OpenLISP
LISP BOF Update
IETF Dublin - July 2008
Slide 26
[email protected]
LISP BOF Update
IETF Dublin - July 2008
Slide 27