Introduction to The Internet

Transcription

1 Itroductio to The Iteret ISP Workshops These materials are licesed uder the Creative Commos Attributio-NoCommercial 4.0 Iteratioal licese ( Last updated 13 th August

2 Ackowledgemets p This material origiated from the Cisco ISP/IXP Workshop Programme developed by Philip Smith & Barry Greee p Use of these materials is ecouraged as log as the source is fully ackowledged ad this otice remais i place p Bug fixes ad improvemets are welcomed Please workshop (at) bgp4all.com Philip Smith 2

3 Itroductio to the Iteret p Topologies ad Defiitios p IP Addressig p Iteret Hierarchy p Gluig it all together 3

4 Topologies ad Defiitios What does all the jargo mea? 4

5 Defiitios p Network Operator p ISP p REN A orgaisatio ruig a IP backboe Provides access to ed users or other etwork operators Sometimes called a Service Provider or a Network Provider Iteret Service Provider Usually commercial, for profit Research & Educatio Network Providig access for Uiversities & Colleges No-commercial, educatioal use oly 5

6 Some Icos Router (layer 3, IP datagram forwardig) Etheret switch (layer 2, packet forwardig) Network Cloud 6

7 Routed Backboe p p p p p Operators build etworks coverig regios Regios ca cover a coutry, subcotiet, or eve global Each regio has poits of presece built by the operator Routers are the ifrastructure Physical circuits ru betwee routers Easy routig cofiguratio, operatio ad troubleshootig The domiat topology used i the Iteret today 7

8 MPLS Backboes p p p Some operators use Multi Protocol Label Switchig (MPLS) MPLS is built o top of router ifrastructure Replaces old ATM techology Tuellig over IP etwork Mai purpose is to provide VPN services Although these ca be implemeted with other tuellig techologies such as GRE 8

9 Poits of Presece p PoP Poit of Presece Physical locatio of operator s equipmet Sometimes called a ode p vpop virtual PoP To the ed user, it looks like a operator s locatio I reality a back hauled access poit Used maily for cosumer access etworks p Hub/SuperPoP large cetral PoP Liks to may PoPs 9

10 PoP Topologies p Core routers High speed truk coectios p Distributio routers Higher port desity, aggregatig etwork edge to the etwork core p Access routers High port desity, coectig the ed users to the etwork p Border routers & Peerig routers Coectios to other providers p Service routers Hostig ad servers p Some fuctios might be hadled by a sigle router 10

11 Typical PoP Desig Other Networks Other Networks Border Backboe lik to aother PoP Network Core Backboe lik to aother PoP Network Operatio Cetre Access Busiess Customer Aggregatio Service ISP Services (DNS, Mail, News, FTP, WWW) Access Cosumer Aggregatio Service Hosted Services 11

12 More Defiitios p Trasit Carryig traffic across a etwork Usually for a fee p Peerig Exchagig routig iformatio ad traffic Usually for o fee Sometimes called settlemet free peerig p Default Where to sed traffic whe there is o explicit match i the routig table 12

13 Peerig ad Trasit example provider A trasit Backboe Provider C provider E peerig IXP-West peerig peerig IXP-East provider B trasit Backboe Provider D provider F A ad B peer for free, but eed trasit arragemets with C ad D to get packets to/from E ad F 13

14 Private Itercoect Autoomous System 334 Provider C border border Provider D Autoomous System 99 14

15 Public Itercoect p A locatio or facility where several etwork operators are preset ad coect to each other over a commo shared media p Why? To save moey, reduce latecy, improve performace p IXP Iteret exchage Poit p NAP Network Access Poit 15

16 Public Itercoect p Cetralised (i oe facility) p Distributed (coected via WAN liks) p Switched itercoect Etheret (Layer 2) Techologies such as SRP, FDDI, ATM, Frame Relay, SMDS ad eve routers have bee used i the past p Each provider establishes peerig relatioship with other providers at IXP Provider border router peers with all other provider border routers 16

17 Public Itercoect ISP 1 ISP 4 ISP 2 IXP ISP 5 ISP 3 ISP 6 Each of these represets a border router i a differet autoomous system 17

18 Operators participatig i Iteret p Brigig all pieces together, Network Operators: Build multiple PoPs i a distributed etwork Build redudat backboes Have redudat exteral coectivity Obtai trasit from upstream providers Get free peerig from local providers at IXPs 18

19 Example Backboe Desig Peer Peer Peer IXP Peer Upstream1 Upstream 2 PoP 2 Backboe Liks Upstream1 Upstream 2 PoP 1 Network Core PoP 3 PoP 4 19

20 IP Addressig Where to get address space ad who from 20

21 IP Addressig Basics p Iteret uses two types of addressig: IPv6 the ew IP protocol IPv4 legacy IP protocol p Iteret uses classless routig Routers must be CIDR capable p Classless IterDomai Routig No routig assumptios made based o the address block Egieers talk i terms of prefix legth For example: /16 ad 2001:DB8::/32 21

22 History of IP Addressig p Pre-CIDR (before 1994) Big etworks got a class A Medium etworks got a class B Small etworks got a class C p The CIDR IPv4 years (1994 to 2010) Sizes of IPv4 allocatios/assigmets made accordig to demostrated eed CLASSLESS p IPv6 adoptio (from 2011) Network Operators get at least oe /32 Ed Sites get /48 IANA s free pool is depleted (February 2011) the size of IPv4 address allocatios ad assigmets is ow very limited 22

23 IP Addressig p IP Address space is a resource shared amogst all Iteret users Regioal Iteret Registries delegated allocatio resposibility by the Iteret Assiged Numbers Authority (IANA) AfriNIC, APNIC, ARIN, LACNIC & RIPE NCC are the five RIRs RIRs allocate address space to Network Operators/Local Iteret Registries Operators/LIRs assig address space to ed customers or other Operators p RIRs address distributio: IPv6 is pletiful IPv4 is very limited 23

24 Address delegatio hierarchy IANA AfriNIC (Africa) APNIC (Asia & Pacific) ARIN (N America) LACNIC (C&S America) RIPE NCC (EU,ME,C Asia) Operators Operators Operators Operators Operators Ed Users Ed Users Ed Users Ed Users Ed Users 24

25 No-portable Address Space p Provider Aggregatable or PA Space Customer uses RIR member s address space while coected to Iteret Customer has to reumber to chage provider Aids cotrol of size of Iteret routig table Need to fragmet provider block whe multihomig p PA space is allocated to the RIR member All assigmets made by the RIR member to ed sites are aouced as a aggregate to the rest of the Iteret 25

26 Portable Address Space p Provider Idepedet or PI Space Customer gets or has address space idepedet of their provider Customer keeps addresses whe chagig provider Is very bad for size of Iteret routig table Is very bad for scalability of the routig system PI space is rarely distributed by the RIRs 26

27 Iteret Hierarchy The peckig order 27

28 Global Iteret: High Level View Global Providers Regioal Provider 1 Regioal Provider 2 Cotet Provider 1 Cotet Provider 2 Access Provider 1 R4 IXP Access Provider 2 Customer Networks 28

29 Detailed View of the Global Iteret p Global Trasit Providers Coect to each other Provide coectivity to Regioal Trasit Providers p Regioal Trasit Providers Coect to each other Provide coectivity to Cotet Providers Provide coectivity to Access Providers p Cotet Providers Cross-coect to Access Providers Peer at IXPs (free traffic to Access Providers) p Access Providers Coect to each other across IXPs (free peerig) Provide access to the ed user 29

30 IPv4 Iteret by BGP Peerigs The IPv4 Default Free Zoe, Jue 2016 Credit to Blair Harriso ad Dea Pemberto Also look at for regioal breakdow ad iteractive graphic 30

31 IPv6 Iteret by BGP Peerigs The IPv6 Default Free Zoe, Jue 2015 Credit to Blair Harriso ad Dea Pemberto Also look at for iteractive graphic 31

32 Categorisig Network Operators Tier 1 Tier 1 $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ Regioal Provider Access Provider IXP Access Provider Tier 1 Tier 1 Regioal Provider Access Provider Regioal Provider Access Provider IXP Access Provider Regioal Provider Access Provider 32

33 Categorisig Network Operators p Tier-1 defiitio: A provider which peers with other Tier-1s ad does NOT pay for trasit Caveat: p May marketig departmets call their service provider a Tier-1 eve though that provider may still pay for trasit to some parts of the Iteret p Regioal providers ofte have the reach of Tier-1s but still have to rely o maybe oe or two Tier-1s to access the whole Iteret They ofte provide access too, via i coutry domestic access etworks p Access providers work exclusively i their locale 33

34 Iter-provider relatioships p Peerig betwee equivalet sizes of service providers (e.g. Regioal to Regioal) Shared cost private itercoectio, equal traffic flows No cost peerig p Peerig across exchage poits If coveiet, of mutual beefit, techically feasible p Fee based peerig Uequal traffic flows, market positio 34

35 Default Free Zoe The default free zoe is made up of Iteret routers which have routig iformatio about the whole Iteret, ad therefore do ot eed to use a default route NB: is ot related to where a etwork operator is i the hierarchy 35

36 Gluig it together 36

37 Gluig it together p Who rus the Iteret? No oe (Defiitely ot ICANN, or the RIRs, or the US, ) p How does it keep workig? Iter-provider busiess relatioships ad the eed for customer reachability esures that the Iteret by ad large fuctios for the commo good p Ay facilities to help keep it workig? Not really. But Techical staff at Network Operators keep workig together! 37

38 Operators keep talkig to each other... p North America NANOG (North America Network Operators Group) NANOG meetigs ad mailig list p Lati America Foro de Redes NAPLA LACNOG p Middle East MENOG (Middle East Network Operators Group) 38

39 Operators keep talkig to each other... p Asia & Pacific APRICOT aual coferece p APOPS mailig list p mailma.apic.et/mailma/listifo/apops PacNOG (Pacific NOG) p mailma.apic.et/mailma/listifo/pacog SANOG (South Asia NOG) p lists.saog.org/mailma/listifo/saog 39

40 Operators keep talkig to each other... p Europe RIPE meetigs, workig groups ad mailig lists e.g. Routig WG: p Africa AfNOG meetigs ad mailig list SAFNOG Souther Africa NOG p Caribbea CaribNOG meetigs ad mailig list p Ad may coutry NOGs 40

41 Operators keep talkig to each other... p Participatio i Peerig Fora Meetigs of the Peerig Coordiators of may etwork operators p Plaig itercoects betwee operators, cotet providers, etc Global Peerig Forum (GPF) Regioal Peerig Fora (Europea, Middle Easter, Asia, Caribbea, Lati America) May NOGs host their ow Peerig Fora May coutries ow have their ow Peerig Fora p IETF meetigs ad mailig lists 41

42 Summary p Topologies ad Defiitios p IP Addressig PA versus PI address space p Iteret Hierarchy Local, Regioal, Global Trasit Providers IXPs p Gluig it all together Egieers cooperate, commo busiess iterests 42

43 Itroductio to The Iteret ISP Workshops 43