Internet Economics HS 2012 Robert Richter, Niklaus Meyer · IP-Routing Revisited (In theory)...

Internet Economics HS 2012 Robert Richter, Niklaus Meyer

1

Agenda •  Introduction

•  Wrap-Up: IP-Routing •  Locator/Identifier Split

•  LISP •  Data Plane •  Control Plane •  Deployment, Interoperability

• Economics •  Current standardization state •  Deployment costs •  Use-Cases

•  Summary

2

What is wrong with IP? •  IPv4 Address Exhaustion

•  IPv6 not yet fully deployed à Topic of another presentation!

• Unsupported Use-Cases •  (Fast) Mobility •  Multi-Homing •  Traffic Engineering (Load Balancing)

•  Large Routing Tables •  Slower routing | More expensive hardware

Introduction 3

IP-Routing Revisited (In theory)

Provider 1(1.0.0.0/9)

Provider 2(1.128.0.0/9)

Provider A(1.0.0.0/8)

Provider B(2.0.0.0/8)

Client A1.128.1.0/24

Client B2.1.1.0/24

2 Entries

1.128.1.0/24

1.0.0.0/9 1.128.0.0/9 2.0.0.0/8

2.1.1.0/24

1.0.0.0/8

Introduction 4

Provider 1(1.0.0.0/9)

Provider 2(1.128.0.0/9)



Client B2.1.1.0/24

Provider Change / «Mobility»

IP-Routing (In practice)

2.1.1.0/24

1.0.0.0/9 2.1.1.0/24

1.0.0.0/8 2.1.1.0/24

2.0.0.0/8 1.128.1.0/24

1.128.0.0/9 1.128.1.0/24

1.0.0.0/8 2.1.1.0/24 1.128.1.0/24

5 Entries

Client A1.128.1.0/24

Multi Homing/ Traffic Engineering

1.128.1.0/24 1.128.1.0/24

Introduction 5

IP-Routing (Table growth)

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

BG

P FI

B E

ntrie

s

Introduction 6

CIDR (1994)

??? (~2001)

Locator/Identifier (Loc/ID) Split •  IP-Address = Identity & Location

•  Identity: Stable & Avoid Renumbering •  Location: Efficient routing (Aggregation)

•  Rekhter’s Law: „Addressing may follow topology or topology may follow addressing. Choose one!“

•  Idea: Split Identity & Location •  Locator/Identifier separation Protocol (LISP) •  Others :

•  Global, Site, End-System (GSE) à IPv6 only •  Network Address Translation (NAT) à Limited end-to-end connectivity •  …

Introduction 7

Routing with Loc/ID Split

Provider 1(1.0.0.0/9)

Provider 2(1.128.0.0/9)



Client AID: 1.128.1.0/24

Loc: 1.128.0.1 & 2.0.0.1

Client BID: 2.1.1.0/24Loc: 1.0.0.1

1.0.0.0/8

1.128.0.0/91.0.0.0/9

1.128.0.11.0.0.1

2.0.0.0/8

2.0.0.1

2 Entries

Assigned by ISP

Assigned by registry

Introduction 8

LOCATOR/IDENTIFIER SEPARATION PROTOCOL Data Plane Control Plane Interoperability & Deployment

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LISP Addresses

•  Two Address Spaces: •  EID: Endpoint Identifier

•  1 constant identifier per device •  RLOC: Routing Locator

•  1-n locations per device. (Changes when device changes it location.)

• EID/RLOC are address agnostic. (IPv4, IPv6, ???) •  à Presentation: IPv4

Locator/Identifier Separation Protocol 10

LISP Functionality • Only 2 network devices (ETR/ITR = xTR) required

•  Egress/Ingress Tunnel Router •  No changes to hosts, other routers, …

• EID-to-RLOC mapping system (≈ DNS)

•  xTR does “Map-and-encap” 1.  Map EID to RLOC 2.  Encapsulate original datagram


Application Layer(HTTP, FTP, SMTP, …)

Transport Layer(TCP, UDP)

Internet Layer(IPv4, IPv6)

Transport/Internet Layer(UDP + IPv4, IPv6)

Link Layer(Ethernet, X.25, Token Ring, ...)

EID

RLOC LISP

Host Stack(end-‐to-‐end)

Core NetworkProvider A11.0.0.0/8

Provider B13.1.0.0/16

R [13.2.0.1]ETR [13.1.1.1]ITR [11.0.0.1]S [10.1.2.3]

Data Plane

SRC = 10.1.2.3DST = 13.2.0.1TCP/UDP/...

HTTP/SMTP/...

IP

SRC = 10.1.2.3DST = 13.2.0.1TCP/UDP/...

HTTP/SMTP/...IP

SRC = 11.0.0.1DST = 13.1.1.1LISP Header (UDP)SRC = 10.1.2.3DST = 13.2.0.1TCP/UDP/...

HTTP/SMTP/...

IPUDP

-‐Data

1 A

encap

B 2

decap


LISP Encapsulation Packet 0 1 2 3 4 5 6 7 8 9

0

0 1 2 3 4 5 6 7 8 9

1

0 1 2 3 4 5 6 7 8 9

2

0 1

3

Version IHL Type of Service Total Length

Identification Flags Fragment Offset

Time to Live Protocol = 17 Header Checksum

Source Address = Source Routing Locator

Destination Address = Destination Routing Locator

Source Port Dest Port (4341)

UDP length UDP Checksum

Flags/Nonce/Others

Locator Reach Bits

Version IHL Type of Service Total Length

Identification Flags Fragment Offset

Time to Live Protocol Header Checksum

Source Address = Source Endpoint Identifier

Destination Address = Destination Endpoint Identifier

OH

(Outer Heade

r)

UDP

IH (Inn

er Heade

r)

LISP

+ 36 Bytes!


Mapping System • Distributed database

•  ITRs find RLOCs by Mapping System • ETRs register EIDs at Mapping System •  Two components: Map Resolver & Map Server • Map Resolver:

•  Interface for ITRs • Map Server:

•  Interface for ETRs •  Each Map Server stores part of EID address space

•  Three main messages: •  Map Request, Map Reply, Map Register


Messages • Map request

•  Send by ITR to Map Resolver to find RLOC for EID

• Map reply •  Send by ETR or Map Server to ITR as reply to map request •  Contains RLOCs with weights (for load balancing)

• Map register •  Send by ETR to Map Server to register EIDs •  Contains all RLOCs and weights •  Can contain proxy bit (Map Reply by Map Server)


Map Request example


Types • Map Server and Map Resolver abstract interfaces •  There are a number of different mapping systems • Examples:

•  ALT: BGP overlay network •  LISP-Tree: DNS based mapping system •  LISP-DHT: Chord DHT based mapping system

• Currently LISP-Tree seems to be proposed solution


LISP-Tree (1) • DNS based solution

•  Hierarchical aggregated namespace •  Iterativ vs. Recursiv •  Map Resolver as interface

•  LISP-Tree != DNS •  Where is mapping? vs. What is mapping?

• Number of advantages: •  Use existing DNS know-how •  Use existing DNS security protocols •  Use existing DNS implementations and infrastructure


LISP-Tree (2)

Picture from [LTREE2010]


Deployment and Interoperability •  Incremental deployment possible

•  Install tunnel routers (client or provider site) •  Setup mapping system (E.g. use existing DNS infrastructure)

•  LISP can coexist with existing networks

•  LISP-Proxys •  LISP-NAT

•  3 Deployment phases planed •  Global routable EIDS •  LISP / no LISP mixed •  LISP only


Consequences ü Smaller routing tables

•  Today: Routing Entries >> Nr of networks (~ 430’000 > 42’000) (Oct. 2012)

•  LISP-Simulation: Routing Entries << Nr of networks

v Overhead for packet forwarding + ~1 μS/Packet •  Encapsula1on and Decapsula1on

v TCP throughput reduced by less than 5% •  Slower packet forwarding + Overhead for header So(ware implementa3on! (OpenLISP on FreeBSD)


ECONOMICS Current standardization state Deployment costs Use-Cases

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Standardization & State (1) •  2006 Amsterdam IAB Routing and Addressing Workshop

•  IETF Draft (2012) •  “It is NOT RECOMMENDED for deployment beyond experimental

situations.” •  Open Issues:

Mapping Systems, Caching of EID-to-RLOC, Security, …

•  RFC 6115 (Recommendation for a Routing Architecture, 2011) •  Open Protocol

•  Developed by Cisco but no Intellectual property held.

•  Drafts for different components and aspects (mapping system, deployment): http://tools.ietf.org/wg/lisp/

Economics 23

Standardization & State (2) • Number of successful applications (see Case-Studies) •  LISP Beta Network

•  More than 4+ years operational •  More than 200 sites, 32 countries •  Participation from Facebook, Google and others

• Number of implementations •  OpenLISP (FreeBSD) •  Cisco LISP (NX-OS) •  LISP-Click (Java based) •  Zlisp (C++ based: Linux, FreeBSD, MacOS)

Economics 24

Deployment costs • One LISP router per upstream connection

•  Owned/Configured by: •  Network Operator •  Service Provider

• Mapping System •  Depending on the mapping system variant! (E.g. Reuse DNS)

•  “Technical costs”: •  Transmission rate decrease <5% •  Mapping System opens new attack surface

(Denial of Service, Injecting wrong mappings, …)

Economics 25

Economical Considerations (Provider) • Smaller routing tables

•  Hardware and personal costs

• Get customers by providing new service • Easier provider change à chance and threat! •  Increase existing service quality with LISP

• Provider areas •  xTR hosting •  Proxy hosting •  Mapping System hosting •  LISP based services

Economics 26

Economical Considerations (Client) • Do not operate these routers

•  Publishing routes is easy à No incentives to reduce routing tables

• Benefits for early adopters •  Multi-Homing, Traffic Engineering •  IPv4 * IPv6 •  Mobility & Avoid renumbering

• Easier provider change

Economics 27

Multi-homing (1) •  Connection to internet by more than one ISP (reliability) •  Distribute traffic among ISPs over BGP is complicated

•  LISP supports effective multi homing (just new ETR/RLOC for EID) •  Map Register message contains weight (traffic engineering)

Picture from [CISCO2012]

Economics 28

Multi-homing (2) •  Desirable for client to increase reliability •  Traffic management essential for optimal bandwidth use

•  Traffic management complicated with BGP •  Experts needed •  Time consuming •  Ineffective routing produces costs

•  Increasing routing tables produce costs

•  Cloud routing as application (call center)

Economics 29

Case-study NJEDge.net • Non-profit technology consortium of academic and

research institutions in New Jersey • Network of ~ 190 institutes • Provider of regional optical network and statewide

broadband access for members • Used for video conferences, distance learning etc.

• Problems with multi-homing and traffic management •  Increasing hardware cost due to complicated BGP routing • Started to deploy LISP in 2011 •  11.000 USD savings per router lifetime

Economics 30

Mobility / Cloud Computing • Change location of host / vm without changing address • Support of Cloud Computing

•  Disaster avoidance •  Data center migration •  Maintenance

• Number of providers •  InTouch (NED) •  VinciConsulting VXNet (USA)


Economics 31

Case-study InTouch NV • Service Provider in Netherlands • Simplify infrastructure and provide easier integration of

services •  Introduced LISP based VPN architecture

•  LISP is "[..] around ten times cheaper than using standard Layer 2 interconnections."

•  "Depending on customer location and availability of connectivity, we’re already seeing reductions of at least 30 percent in capital expense and 50 percent in operating costs."

Economics 32

Mobile-Node •  Mobile-node changes access network •  Mobile-node can keep IP •  Mobile-node contains xTRs


Economics 33

IPv6 deployment •  Support IPv6 deployment •  Minimal infrastructure changes •  LISP uses address family agnostic encapsulation mechanism •  IPv6 over IPv4 core and other way around


Economics 34

Summary •  IP-Address split

•  Location & Identity à IP Number Portability

•  LISP •  Open Standard •  Additional Features (Multi-Homing, Traffic Engineering, …) •  Simple & Incremental deployment

•  Mapping System (~DNS for EID-to-RLOC) •  More than 6 variants •  Issues: Security, Performance, Fast Updates, …

Summary 35

QUESTIONS / DISCUSSION

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Will LISP be widely deployed?

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Why develop an open protocol?

• Open Protocol à No intellectual property held by CISCO

• But mostly CISCO employees involved

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Is there a real use-case for LISP? • Michael Leonard (Technical Marketing Manager at Juniper)

(http://forums.juniper.net/t5/Data-Center-Directions-Michael/Is-There-a-Real-Use-Case-for-LISP-The-Locator-ID-Separation/ba-p/152472)

•  According to the LISP Protocol Specification, LISP’s only goal is in reducing routing table size. However, Cisco has also positioned LISP as an IPv6 transition mechanism, for mobility of virtual machines, and now fast mobility for Mobile IP. In all cases LISP competes with alternative solutions that do not rely on LISP’s unique and relatively unproven mapping and packet transport mechanisms.

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Who operates the Mapping System?

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BACKUP SLIDES

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Comparison to others LISP GSE NAT

Map-and-encap Address Rewriting Address Rewriting

EID IPv6 postfix (64Bit) Private IP (10.0.0.0/8,…)

RLOC IPv6 prefix (64Bit) Public IP

-  Requires mapping system

-  IPv6 only -  Changes to hosts

required

-  Endpoints not reachable

-  IPv4/6 intermixing -  Traffic engineering -  Mobility -  Multi-homing

-  Multi-homing

Test network Draft only In use

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Glossary • EID: Endpoint Identifier • RLOC: Routing Locator •  ITR: Ingress Tunnel Router • ETR: Egress Tunnel Router •  xTR: ETR/ITR

•  ISP: Internet service provider • CIDR: Classless Inter-Domain Routing • BGP: Border Gateway Protocol

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Referenzen •  [LTREE2010] LISP-TREE: A DNS Hierarchy to Support the LISP Mapping System, 2010, L. Jakab, A. C.-Aparicio, F.

Coras, D. Saucez, O. Bonaventure

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Internet Economics HS 2012 Robert Richter, Niklaus Meyer · IP-Routing Revisited (In theory)...

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