Download vince-fuller-lisp-idr-dublin-2008

LISP and BGP
IDR WG, IETF Dublin, July, 2008
Vince Fuller (for the LISP crew)
Agenda
• Motivation for LISP (and ALT)
• How LISP+ALT uses BGP
• A few considerations
IDR WG
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
IDR WG
IETF Dublin, July, 2008
Slide 3
Separate EID/RLOC topologies
“Addressing can follow topology or topology can follow
addressing – choose one” –Y.R.
•
•
•
•
ID/LOC separation avoids this dilemma
EIDs uses organization/geo hierarchy
RLOCs follow network topology
Reduce global routing state through RLOC
aggregation
• EID prefixes are not generally visible in
global routing system
IDR WG
IETF Dublin, July, 2008
Slide 4
EID vs RLOC assignment
Provider A
10.0.0.0/8
ISP allocates 1 locator address
per physical attachment point
(follows network topology)
R1
Legend:
EIDs -> Green
Locators -> Red
IDR WG
R2
Provider B
11.0.0.0/8
RIR allocates EID-prefixes
(follows org/geo hierarchy)
Site
PI EID-prefix 240.1.0.0/16
IETF Dublin, July, 2008
Slide 5
LISP+ALT: What, How and Why
• Hybrid push/pull approach
– ALT pushes aggregates - find ETRs for EID
– ITR uses LISP to find RLOCs for specific EID
• Hierarchical EID prefix assignment
– Aggregation of EID prefixes
• Tunnel-based overlay network
• BGP used to advertise EIDs on overlay
– Why invent something new? (or use DNS?)
• Option for data-triggered Map-Replies
IDR WG
IETF Dublin, July, 2008
Slide 6
LISP+ALT in action
EID-prefix
240.0.0.0/24
?
ITR
Legend:
?
?
< - 240.1.0.0/16
ALT-rtr
ALT-rtr
ETR
EID-prefix
240.1.1.0/24
ALT-rtr
ALT-rtr
ALT-rtr
EIDs -> Green
240.0.0.1 -> 240.1.1.1
240.0.0.1 -> 240.1.1.1
240.0.0.1 -> 240.1.1.1
ITR
240.0.0.1 -> 240.1.1.1
11.0.0.1 -> 240.1.1.1
11.0.0.1 -> 240.1.1.1
ETR
ALT-rtr
Locators -> Red
GRE Tunnel
LAT
Low Opex
Physical link
Data Packet
Map-Request
Map-Reply
IDR WG
ETR
11.0.0.1 -> 1.1.1.1
?
240.0.0.1 -> 240.1.1.1
1.1.1.1 -> 11.0.0.1
IETF Dublin, July, 2008
Slide 7
Securing the mapping system
• ALT can use existing/proposed BGP
security mechanisms (SBGP, etc.)
• DOS-mitigation using well-known
control plane rate-limiting techniques
• Nonce in LISP protocol exchange
• More needed?
IDR WG
IETF Dublin, July, 2008
Slide 8
Non-BGP traffic engineering
• ALT separates ETR discovery from the
ITR-ETR mapping exchange
– very coarse prefixes globally-advertised
– more-specific info exchanged where needed
• Regional ETRs could return morespecific mappings for simple TE
• Alternative to current practice of
advertising more-specific prefixes
IDR WG
IETF Dublin, July, 2008
Slide 9
Simple BGP configs
• No BGP changes required for LISP+ALT
– None made for pilot deployment
– Though separate AFI/SAFI might be a
good idea for debugging/management
• No need for route-reflectors, etc.
• May use iBGP in some cases
IDR WG
IETF Dublin, July, 2008
Slide 10
Questions/Comments?
Contact us: [email protected]
Information: http://www.lisp4.net
OpenLISP: http://inl.info.ucl.ac.be
Thanks!
IDR WG
IETF Dublin, July, 2008
Slide 11