PERN2 LOW LEVEL DESIGN (Routing Implementation)

1. PERN2 LOW LEVEL DESIGN(Routing Implementation) By: Jawad Raza Manager Network & Operations jraza@hec.gov.pk Friday 30th August,2013

2. NUST H-12 Arid IIU NUML NDU NUST,RWP BU FAST AIOU IST PUUST FJWU NCP AUP AU CIIT PU IMS QAU PIES UET GU HEC(ISB) KU UOM PASC UET UVAS NCA CoAE LCWU GIK HU HEC(Pesh) KCW PMA Uop-OLD GCUL Legend PU-NEW NCOEIMB BUITMS(QTA) 10G Link FAST HEC(lhr) UHS 1G Link VU UOB LSE LUMS CSC UOE BZU(MLT) UOG GCU UOA SU SBKWU IU(BWP) FAST PNA CPSP HEC(khi) HU KU IBA NED USINDH(HYD) AKU SSUET HEJ DUHS QeA IBA UET,Khuzdar MUET LU SAU LUMHS SALU High Level Design AUF(FSD)

3. Topology Design

4. Planning

5. Campus-A User-A Isb-PoP Lhr-PoP Internet Service Provider User-B Core layer Campus-B Level-1: Three (3) cRA-PoP routers, located at the major cities of Pakistan Level-2: Five (5) sRA-PoP routers, located at the small cities Level-3: Seven (7) LA-PoP router, to cover the metro cities Khi-PoP User-C Stanford University, NRENs Link TEIN3 Network

6. Campus-A User-A Isb-PoP Lhr-PoP Internet Service Provider User-B Core layer Campus-B Level-1: Three (3) cRA-PoP routers, located at the major cities of Pakistan Level-2: Five (5) sRA-PoP routers, located at the small cities Level-3: Seven (7) LA-PoP router, to cover the metro cities Khi-PoP NRENs Link TEIN3 Network

7. Campus-A User-A Isb-PoP Internet Service Provider User-B Traffic Categories Campus-B A – Internet traffic: IP Transit Connectivity B – Intranet traffic: Connectivity among the PERN2 Campuses Intranet Bandwidth should be Separate from Internet Bandwidth C – International NREN (R&D) traffic For the R&D traffic Bandwidth must be separate from Intranet and Internet Khi-PoP Stanford (USA) NRENs Connectivity TEIN3 Network

8. Routing Basics

9. Routing Basic • IPv4 Addressing • Routing & Forwarding • Routing Protocols • IGPs • EGP

10. Router • What does the router do? • Find path & forward packet…… if primary path is not available find alternate path…. ?

11. Routing vs Forwarding • Routing: • Selection of Path in the networks along with which to send network traffic • Forwarding: • Moving packets between interfaces according to the “directions”

12. IP Routing • Path derived from information received from a routing protocol • Several alternative paths may exist best next hop stored in forwarding table • Decisions are updated periodically or as topology changes (event driven) • Decisions are based on: • Topology, policies and metrics (hop count, filtering, delay, bandwidth, etc.

13. IP Route • Based on destination IP packets 40/8 R3 Packet Destination: 10.1.1.1 R2 R1 10/16 R4 10/16 R4 20/8 R6 30/8  R5 40/8  R30

14. IPv4 Address • 32 bits long address, • Range from 1.0.0.0 to 223.255.255.255 • Serves with two principal function i.e Network portion and Host Portion • Address & Mask written as • 192.168.1.1 255.255.255.0 or 192.168.1.1/24 • Some of the IP addresses are reserved • Private IP Addresses • Multicast IP Addresses

15. Routing Protocols IGP & EGP • Interior Gateway Protocols • within a single autonomous system • single network administration • unique routing policy • make best use of network resources • Exterior Gateway Protocols • among different autonomous systems • independent administrative entities • communication between independent network infrastructures

16. Autonomous System (AS) • Collection of networks with same routing policy • Single routing protocol • Usually under single ownership, trust and administrative control • Identified by a unique number AS 100

17. IGP & EGP Protocols • IGP • RIP • IS-IS • OSPF • EGP • BGP

18. PERN2 Selection of IGPs

19. IGP User-A • Single network administration Campus-A • unique routing policy Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

20. IGP EGP User-A • Single network administration Campus-A • unique routing policy Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

21. IGPs RIP OSPF IS-IS User-A Campus-A Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

22. RIP(Routing Information Protocol)

23. What is RIP • Routing Information Protocol • Two Versions of RIP • RIPv1 • RIP v2 • Distance Vector Routing Protocol • RIPng (Next Generation) design for IPv6 routing

24. Distance Vector Routing • Routers are advertised as vector of distance and direction. • Direction is represented by next hop address and exit interface. • Whereas Distance uses metrics such as hop count • Updates are performed periodically in a distance vector protocol where all router's routing table is sent to all its neighbors • The cost of reaching a destination is calculated using various route metrics, RIP uses hop count to calculate metric.

25. RIP in large ISP • Hop count Limit to 15 • RIP eats lots of bandwidth (all broadcast traffic) on large networks • RIP takes 30 – 60 seconds to converge

26. IGPs RIP OSPF IS-IS User-A Campus-A Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

27. OSPFOpen Shortest Path First

28. OSPF • Most Widely used IGP routing protocol • Link State Protocol • Allow routers to dynamically learn routes from other routers and to advertise routes to other routers.

29. OSPF Operations • OSPF operation can be divided into three categories Neighbor and Adjacency initialization LSA Flooding SPF Calculation

30. Link State Routing Protocol • In a link-state protocol, the network can be viewed as a jigsaw puzzle • Each jigsaw piece holds one router • Each router creates a packet which represents its own jigsaw piece • This packet is called a Link State Advertisement (LSA) LSP for router-B LSP for router-A to A to B to E to D to C to E to B to A LSP for router E to A to B to C to D LSP for router-D LSP for router-C

31. These packets are flooded everywhere • Therefore each router receives all pieces of the jigsaw puzzle • Each routers compute SPF algorithm to put the pieces together Input: all jigsaw puzzle pieces Output: Area or network topology tree Shortest Path Tree • All routers exchange all LSAs via a reliable flooding mechanism Link

32. OSPF Areas Area 2 • Area is a group of contiguous hosts and networks • Reduces routing traffic • Per area topology database • Backbone area MUST be contiguous • All other areas must be connected to the backbone Area 1 R2 R1 R4 R3 Area 0 Backbone Area R6 R5 R8 R11 R7 R10 R9 R12 Area 3 Area 4

33. OSPF Features • Support Large Network • Fast Update and Convergence • Support VLSM • Dividing the whole routing domain into different areas • Support Authentication

34. OSPFv3 • OSPF for IPv6 • Based on OSPFv2, with enhancements • Distributes IPv6 prefixes • Runs directly over IPv6 • Ships-in-the-night with OSPFv2

35. IGPs RIP OSPF IS-IS User-A Campus-A Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

36. ISIS(Intermediate System to Intermediate System)

37. What is ISIS • IS an IGP (Interior Gateway Protocol) scalable only for dynamic routing within a domain • Link State Protocol • IS a dynamic routing protocol based on SPF routing algorithm • IS is “OSI speak” for router • Easily extendable for other routing protocol Mainly IPv6

38. Hierarchy • IS-IS has 2 levels of hierarchy • Level-1 (L1) • Neighbors only in the same AREA, and information about its own area L1 L1 L1 L1 Adjacencies R3 R2 R1

39. Why IS-IS? • Embraced by the large tier1 ISPs. • Proven to be a very stable and scalable, with very fast convergence. • Encodes the packet(s) in TLV format. • Flexible protocol in terms of tuning and easily extensible to new features (MPLS-TE etc). • It runs directly over Layer 2. (next to IP).

40. IGPs RIP OSPF IS-IS User-A Campus-A Isb-PoP Lhr-PoP Internet Service Provider User-B Campus-B Khi-PoP TEIN3 Network

41. ISIS and OSPF • Similarities: • OSPF and IS-IS are more similar than they are different. • Both are Link State Routing Protocol • Both ISIS & OSPF Support Hierarchical Routing • Both Support VLSM, CDIR, Authentication, Multiple Paths • ISIS & OSPF Similar Terminologies • OSPF ISIS • Host End System (ES) • Router Intermediate System (IS) • Link Circuit • Packet Protocol Data Unit (PDU • Link-State Advertisement (LSA) Link-State PDU (LSP) • Area Sub domain (area) • Non-backbone area Level-1 area • Backbone area Level-2 Sub domain (backbone) • Area Border Router (ABR) L1L2 router

42. ISIS over OSPF • Difference:

43. ISIS over OSPF C I S C O • “Which IGP should an ISP choose? • Both OSPF and ISIS use Dijkstra SPF algorithm • Exhibit same convergence properties • ISIS can runs on data link layer, OSPF runs on IP layer • Biggest ISPs tend to use ISIS • Main ISIS implementations more tuneable than equivalent OSPF implementations “

44. References • GEANT2 http://www.geant2.net/server/show/nav.1525 : “The IGP currently used in GÉANT is the ISO IGP IS-IS (Intermediate System to Intermediate System), which provides support for both IPv4 and IPv6”. • CANARIE http://www.canarie.ca/canet4/services/c4_routing_policy.pdf “The Intermediate System-to-Intermediate System (IS-IS) routing protocol is the IGP for CA*net 4, where a single IS-IS Level 2 area is defined. IS-IS was chosen over OSPF mainly for network migration considerations as well as for early release of advanced backbone network feature support by major routing vendors”. • Ufone Pakistan (Largest Telecomm Operator in Pakistan) • China Telecomm (An extra-large State-owned telecom operator in China) • CMPaK (Telecomm Operator in Pakistan)

45. IS-IS

46. ISIS Cost (Core) 10 ISB-HEC 10 PSH-HEC 10 10 10 Legend 10 10 10G Link (Optic Fiber) 10G Link (Long Haul Fiber) 10 LHR-HEC FSD-AUF QTA-BUITMS 10 10 10 10 MLT-BZU 10 10 10 10 10 HYD-USINDH 10 10 KHI-HEC IS-IS enable interface

47. OSPF Design (PoP & Access) International University Service, Webserver, Mailserver, etc. Internet Service VOIP Service ISIS Core layer One interlink ip NAT and one default route pointing to NE20E OSPF NE20E (CPE) NE40E/80E (PE) VOD,IPTV, Streaming, etc. • OSPF process Between PoP Router & Access router • Under different Management • Easier to Manage for a campus environment

48. Applications topology (POP Site) GE Optic link International University Service,Webserver, Mailserver, etc. FE Electric link Internet Service VOIP Service NE20E (CPE) MPLS Backbone One interlink ip NAT and one default route pointing to NE20E NE40E/80E (PE) VOD,IPTV, Streaming, etc. Subinterface10: enable ISIS/MPLS for L2VPN Subinterface20: Internet Subinterface30: NREN Subinterface40: Intranet NMS Servers &Clients. L2VPN Service CPE: .

49. IS-IS OSPF BGP Internet Service Provider TEIN3 Network

50. BGP(Border Gateway Protocol)