2. By: Jawad Raza Manager Network & Operations jraza@hec.gov.pk Friday 30 th August,2013

3. AUF(FSD)

4. Topology Design

6. 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 Internet Service Provider User-B User-A Campus-A Campus-B Isb-PoP Khi-PoP Lhr-PoP NRENs Link TEIN3 Network User-C Stanford University,

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

8. 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 Internet Service Provider NRENs Connectivity TEIN3 Network User-A User-B Campus-A Campus-B Isb-PoP Khi-PoP Stanford (USA)

10.  IPv4 Addressing  Routing & Forwarding  Routing Protocols ◦ IGPs ◦ EGP

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

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

13.  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.

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

15.  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

16.  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

17.  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

18.  IGP ◦ RIP ◦ IS-IS ◦ OSPF  EGP ◦ BGP

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

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

22. Internet Service Provider TEIN3 Network User-A User-B Campus-A Campus-B Isb-PoP Khi-PoP Lhr-PoP IGPs 1.RIP 2.OSPF 3.IS-IS

24.  Routing Information Protocol ◦ Two Versions of RIP  RIPv1  RIP v2  Distance Vector Routing Protocol  RIPng (Next Generation) design for IPv6 routing

25.  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.

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

27. Internet Service Provider TEIN3 Network User-A User-B Campus-A Campus-B Isb-PoP Khi-PoP Lhr-PoP IGPs 1.RIP 2.OSPF 3.IS-IS

29.  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.

30.  OSPF operation can be divided into three categories Neighbor and Adjacency initialization LSA Flooding SPF Calculation

31.  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 A to B to A LSP for router E to B to C to D LSP for router-D LSP for router-C

32.  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

33.  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 Area 2 Area 3 Area 4 Area 0 Backbone Area R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12

34.  Support Large Network  Fast Update and Convergence  Support VLSM  Dividing the whole routing domain into different areas  Support Authentication

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

36. Internet Service Provider TEIN3 Network User-A User-B Campus-A Campus-B Isb-PoP Khi-PoP Lhr-PoP IGPs 1.RIP 2.OSPF 3.IS-IS

38.  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

39.  IS-IS has 2 levels of hierarchy ◦ Level-1 (L1)  Neighbors only in the same AREA, and information about its own area L1 Adjacencies

40.  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).

41. Internet Service Provider TEIN3 Network User-A User-B Campus-A Campus-B Isb-PoP Khi-PoP Lhr-PoP IGPs 1.RIP 2.OSPF 3.IS-IS

42.  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 ◦ OSPFISIS  Host End System (ES)  RouterIntermediate System (IS)  Link Circuit  Packet Protocol Data Unit (PDU  Link-State Advertisement (LSA) Link-State PDU (LSP)  Area Sub domain (area)  Non-backbone areaLevel-1 area  Backbone area Level-2 Sub domain (backbone)  Area Border Router (ABR)L1L2 router

43.  Difference:

44. 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 “

45.  GEANT2 http://www.geant2.net/server/show/nav.1525 :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.pdfhttp://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 )

46. IS-IS

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

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

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

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

52.  A Routing protocol used to exchange routing information between different Networks  The Autonomous System is BGP’s fundamental operating unit ◦ It is used to uniquely identify networks with a common routing policy

53.  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

54.  Two ranges ◦ 0-65535 (original 16-bit range) ◦ 65536-4294967295 (32-bit range - RFC4893)  Usage: ◦ 0 and 65535 (reserved) ◦ 1-64495 (public Internet) ◦ 64496-64511(documentation - RFC5398) ◦ 64512-65534 (private use only) ◦ 23456 (represent 32-bit range in 16-bit world) ◦ 65536-65551 (documentation - RFC5398) ◦ 65552-4294967295 (public Internet)  ASNs are distributed by the Regional Internet Registries ◦ They are also available from upstream ISPs who are members of one of the RIRs  The RIRs also have received 1024 32-bit ASNs each ◦ Out of 190 allocations, around 50 are visible on the Internet ◦ See www.iana.org/assignments/as-numberswww.iana.org/assignments/as-numbers

55.  Multi-homing with BGP is a way to manage redundant links to multiple ISPs.  Maintaining links to multiple Internet provider (Usually 2 or 3) and using BGP to send routs and receive full routing tables from these providers ISP-2 ISP-1 Multi-homed Customer AS 100 Route Received Prefix announcement Route Received

56. ISP-2 ISP-1 PE KHI-HEC-P-PE-EGRESS-NE80E ISB-HEC-P-PE-EGRESS-NE80E IBGP PE PE PE EBGP ISP-2 EBGP ISP-1 EBGP

57. eBGP peering ISP1 ASN-1 ISP2 ASN-2 eBGP peering Full Routing feed Received Router Receives Full routing table from both ISP’s, and store the best available routes reveries from both these ISPs,

58. eBGP peering ISP1 ASN-1 ISP2 ASN-2 eBGP peering PERN2 Prefixes P1/24 P2/24 P3/24 P4/24 P5/24 P6/24 P7/24 P8/24 Primary Prefixs P1/24 P2/24 P3/24 P4/24 Primary Prefixs P5/24 P6/24 P7/24 P8/24 Prepend Prefixs P5/24 P6/24 P7/24 P8/24 Prepend Prefixs P1/24 P2/24 P3/24 P4/24 Prefix's Announcement BGP Policy routing has been applied, AS-PATH Prepend for the load balancing on Incoming traffic

59. eBGP peering ISP1 ASN-1 ISP2 ASN-2 PERN2 Prefixes P1/24 P2/24 P3/24 P4/24 P5/24 P6/24 P7/24 P8/24 Primary Prefixs P1/24 P2/24 P3/24 P4/24 Primary Prefixs P5/24 P6/24 P7/24 P8/24 Prepend Prefixs P5/24 P6/24 P7/24 P8/24 Prepend Prefixs P1/24 P2/24 P3/24 P4/24 Prefix's Announcement In Case of One link failure, the prefix prepend traffic will be shifted to backup link. Prepend Prefixs P5/24 P6/24 P7/24 P8/24 eBGP peering Prefix's Announcement

60.  eBGP is used to learn the Internet Routes and advertised PERN2 IP prefixes on Internet  iBGP then originate connected networks and also pass on prefixes learned from outside the ASN  ISIS has been used as an IGP Protocol on the core network of PERN2  OSPF has been used as an IGP protocol between the core and access network.

61.  Service Communicator ◦ Generates Tickets ◦ http://sc.hec.gov.pk http://sc.hec.gov.pk ◦ 24/7 Help Line also Available i.e  111-11PERN  051-9040PERN ◦ Complain also can log by email pern2noc@hec.gov.pk pern2noc@hec.gov.pk