Darrel Lewis and Margaret Wasserman IETF 76 Hiroshima Japan Slide 2 Agenda Introduction Deployment scenario implication for the LISP Specification Survey of LISP Network Elements XTRs ID: 476209
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Slide1
LISP Deployment Scenarios
Darrel Lewis
and
Margaret Wasserman
IETF 76, Hiroshima, JapanSlide2
Slide 2
Agenda
Introduction : Deployment scenario implication for the LISP Specification
Survey of LISP Network Elements
XTRs
Map Servers
Map Resolvers
Proxy ITRs
Proxy ETRs
Gauge level of interest in developing an informational draftSlide3
Slide 3
Introduction
The goal of this presentation is to inform the community about how we are expecting LISP to be deployed
Help to bound the discussion within practical scenarios
Covers cases we expect to be most common, not all possibilities are covered
For each element we’ll discuss possible deployment scenarios
And hopefully the tradeoffs
For each element we’ll discuss the impact of deployment scenarios on the specSlide4
Slide 4
LISP xTRs as the CE
R1
R2
BGP
Provider A
10.0.0.0/8
Provider B
11.0.0.0/8
Provider Independent (PI)
15.0.0.0/8
InternetSlide5
Slide 5
LISP xTRs
xTRs at customer premise (CE)
Advantages
Site control of egress TE
Site control of ingress TE
Encapsulate last, Decapsulate first
Disadvantages
None?
Spec implications
LISP needs to work on typical CPE hardware
Higher-end routers for mid-to-large enterprise
Lower-end routers/CPE devices for SOHO Slide6
Slide 6
LISP xTRs (cont)
ITR and ETR split into different devices for a site
Advantages
Best path vs. shortest path
Disadvantages
Additional mechanism (such as OSPF) needed for ITRs to detect ETR liveness
Site must carry full routes
Spec implications
Need for functional separation of ITR/ETRSlide7
Slide 7
Split ITR/ETR Site
Provider A
1.0.0.0/8
Provider B
2.0.0.0/8
S
ITR
ITR
4G Provider
4.0.0.0/8
S1
S2
LISP
EID-prefix
10.0.0.0/8
1.0.0.1
2.0.0.1
Encapsulate
->
3G Provider
3.0.0.0/8
ETR
ETR
S3
S4
iBGP
<-
DecapsulateSlide8
Slide 8
LISP xTRs
xTRs at the Provider Edge (PE)
Advantages
Site doesn’t have to upgrade CE
Multi-homing to a single SP might work
Degenerate of the VPN case local NAT in
Disadvantages
Site loses control of egress TE
Locator liveness is problematic
Implications
LISP would need to work on typical PE hardwareSlide9
Slide 9
LISP xTRs (cont)
xTRs for Inter-Service Provider TE
Advantages
Separate mapping database shared between service providers
Bilateral agreements allow traffic engineering across multiple MPLS ASes
Disadvantages
Extra header, add’l looked, database maintenance
Implications
Requires support for two levels of LISP headersSlide10
Slide 10
Map Server
Authenticated Map Register messages are sent to Map Servers by ETRs
Map Server(s) will probably be provided by an EID registrar
Redundant servers are desirable
Impacts:
Need mechanism to configure EID prefix(es), keys and map server address(es) on ETRsSlide11
Slide 11
Map Resolver
Map Requests are sent to Map Resolvers by ITRs
Map resolvers will probably be provided by Internet Service Providers
Impacts:
Need DHCP option or other mechanism to configure map resolver address(es) on ITRsSlide12
Slide 12
Proxy-ITRs
R-prefix
65.1.0.0/16
R-prefix
65.2.0.0/16
R-prefix
65.3.0.0/16
65.0.0.0/12
66.0.0.0/12
Infrastructure Solution
Legend:
LISP Sites -> Green (and EIDs)
non-LISP Sites -> Red (and RLOCs)
xTR
NR-prefix
1.2.0.0/16
NR-prefix
1.1.0.0/16
NR-prefix
1.3.0.0/16
66.1.1.1
66.2.2.2
66.3.3.3
65.9.2.1
P-ITR
BGP Advertise:
1.0.0.0/8
P-ITR
BGP Advertise:
1.0.0.0/8
P-ITR
BGP Advertise:
1.0.0.0/865.9.3.165.9.1.1
65.1.1.1 ->
1.1.1.1
(1)
1.1.1.1 ->
65.1.1.1
(3)
Encapsulate
65.1.1.1
-> 1.1.1.1
65.9.1.1 -> 66.1.1.1
(2)Slide13
Slide 13
LISP Proxy-ITRs
Advantages
Allow connectivity between LISP nodes and non-LISP nodes
Early Adopter LISP sites see benefits of LISP
Disadvantages
Non-LISP traffic may take suboptimal route through Proxy ITR (compared to LISP-NAT)
Implications
Defined in Interworking specificationSlide14
Slide 14
Proxy-ETRs
R-prefix
65.1.0.0/16
R-prefix
65.2.0.0/16
R-prefix
65.3.0.0/16
65.0.0.0/12
66.0.0.0/12
Legend:
LISP Sites -> Green (and EIDs)
non-LISP Sites -> Red (and RLOCs)
xTR
NR-prefix
1.2.0.0/16
NR-prefix
1.1.0.0/16
NR-prefix
1.3.0.0/16
66.1.1.1
66.2.2.2
66.3.3.3
P-ETR
65.1.1.1 <-
1.1.1.1
(2)
Encapsulate
65.1.1.1
<-
1.1.1.1
65.10.1.1 <- 66.1.1.1
(1)
65.9.2.1
P-ITR
BGP Advertise:
1.0.0.0/8
P-ITR
BGP Advertise:
1.0.0.0/8
65.9.1.1
65.10.1.1
EncapsulateSlide15
Slide 15
LISP Proxy-ETRs
Advantages
Allows LISP nodes in sites with URPF restrictions to communicate with non-LISP nodes
Allows LISP in sites without natvie IPv6 support to communication with LISP nodes that have only v6 RLOCs
Can (should?!) be separate devices from Proxy-ITRs
Disadvantages
Packets may take longer path through P-ETR
Implications
Defined in Interworking specificationSlide16
Slide 16
Early Adopter/Experimental
xTRs behind a NAT
Advantages:
Allows LISP connectivity to/from sites behind a NAT for test network/early deployment
Disadvantages:
Somewhat Complex to configure
Implications
:
Limited NAT traversal needed
1 xTR at global address, static port forwarding for 4341 & 4342
Dynamic Locator in ETR Database
Needed for short term, when LISP is not integrated with provider-supplied CPESlide17
Slide 17
Wrap UP
Is further work needed in this area?
Should we write an informational draft?