1. IDR WG, IETF Dublin, July, 2008 Vince Fuller (for the LISP crew)
LISP and BGP
IDR WG, IETF Dublin, July, 2008
Vince Fuller (for the LISP crew)

2. Agenda Motivation for LISP (and ALT) How LISP+ALT uses BGP
A few considerations
IDR WG
IETF Dublin, July, 2008

3. 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

4. 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

5. EID vs RLOC assignment ISP allocates 1 locator address
per physical attachment point
(follows network topology)
Provider A /8
Provider B /8 R1 R2
RIR allocates EID-prefixes
(follows org/geo hierarchy)
Site
Legend:
EIDs -> Green
Locators -> Red
PI EID-prefix /16
IDR WG
IETF Dublin, July, 2008

6. 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

7. LISP+ALT in action ? ? ? ? EID-prefix 240.0.0.0/24 EID-prefix
>
> ?
>
> ?
>
EID-prefix
/24
ETR
EID-prefix
/24
ITR ?
< /24
< /24
< /16
>
>
ALT-rtr
ALT-rtr
>
>
ETR
ITR
ALT-rtr
ALT-rtr
Legend:
EIDs -> Green
Locators -> Red
GRE Tunnel
Low Opex
Physical link
Data Packet
Map-Request
Map-Reply
ALT-rtr
ALT-rtr
ETR
LAT ?
IDR WG
IETF Dublin, July, 2008

8. 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

9. 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 more- specific mappings for simple TE
Alternative to current practice of advertising more-specific prefixes
IDR WG
IETF Dublin, July, 2008

10. 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

11. Questions/Comments? Thanks!
Contact us:
Information:
OpenLISP:
Thanks!
IDR WG
IETF Dublin, July, 2008
Slide 11