By: Jawad Raza Manager Network & Operations [email protected] Friday 30 th August,2013.
-
Upload
muriel-gilmore -
Category
Documents
-
view
218 -
download
0
Transcript of By: Jawad Raza Manager Network & Operations [email protected] Friday 30 th August,2013.
PERN2 LOW LEVEL DESIGN
(Routing Implementation)By:Jawad RazaManager Network & [email protected]
Friday 30th August,2013
HEC(khi)
Legend
10G Link1G Link
BUITMS(QTA)
USINDH(HYD)
BZU(MLT)
GCUL Uop-OLDKCW
LCWUNCA
PASCUETUVAS
PU-NEW NCOEIMB
FAST
UHSVU
HEC(lhr)
LSE
LUMSUOEUOG
SUUOAGCU
FAST
CPSP
PNA
KUHU
IBA
NEDSSUET
HEJAKUDUHS
UET,KhuzdarLU
QeAMUET
LUMHS SALUSAU
IBA
UOB
CSC
SBKWU
AUPIMS
PU
UETGU
KUUOM
CoAEGIK HU
PMAHEC(Pesh)
IU(BWP)
HEC(ISB)
PUUSTAIOU
NUMLFAST
IIUArid NUST H-12
BU
AU
FJWU
QAU
NDU NUST,RWP
IST
NCP
CIIT
PIES
AUF(FSD)
High Level Design
Topology Design
Planning
Core layer
• 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
InternetServiceProvider
User-B
User-A
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
NRENs LinkTEIN3 Network
User-C
Stanford University,
Core layer
1. Level-1: 1. Three (3) cRA-PoP
routers, located at the major cities of Pakistan
2. Level-2:
1. Five (5) sRA-PoP routers, located at the small cities
3. Level-3:1. Seven (7) LA-PoP router,
to cover the metro cities
InternetServiceProvider
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
NRENs LinkTEIN3 Network
Traffic Categories
• 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
InternetServiceProvider
NRENs ConnectivityTEIN3 Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Stanford (USA)
Routing Basics
IPv4 Addressing Routing & Forwarding Routing Protocols
◦ IGPs◦ EGP
Routing Basic
What does the router do?
Find path & forward packet…… if primary path is not available find alternate path….
Router
?
Routing:◦ Selection of Path in the networks along with which to send network traffic
Forwarding:◦ Moving packets between interfaces according to the “directions”
Routing vs Forwarding
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.
IP Routing
Based on destination IP packets
IP Route
R1
R4
R3
R2
10/16 R4
20/8 R630/8 R5
40/8 R30
Packet Destination:10.1.1.1
10/16
40/8
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
IPv4 Address
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
Routing Protocols IGP & EGP
Collection of networks with same routing policy Single routing protocol Usually under single ownership, trust and administrative control Identified by a unique number
Autonomous System (AS)
AS 100
IGP◦ RIP◦ IS-IS◦ OSPF
EGP◦ BGP
IGP & EGP Protocols
PERN2 Selection of IGPs
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGP
Single network administration
unique routing policy
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGP
Single network administration
unique routing policy
EGP
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGPs1. RIP2.
OSPF3. IS-IS
RIP (Routing Information Protocol)
Routing Information Protocol◦ Two Versions of RIP
RIPv1 RIP v2
Distance Vector Routing Protocol
RIPng (Next Generation) design for IPv6 routing
What is RIP
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.
Distance Vector Routing
Hop count Limit to 15
RIP eats lots of bandwidth (all broadcast traffic) on large networks
RIP takes 30 – 60 seconds to converge
RIP in large ISP
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGPs1. RIP2.
OSPF3. IS-IS
OSPFOpen Shortest Path First
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.
OSPF
OSPF operation can be divided into three categories
OSPF Operations
Neighbor and Adjacency initialization
LSA Flooding
SPF Calculation
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)
Link State Routing Protocol
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
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 treeShortest Path Tree
All routers exchange all LSAsvia a reliable flooding mechanism Link
OSPF Areas 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 0Backbone Area
R1
R2
R3
R4
R5R6
R7 R8
R9
R10 R11
R12
Support Large Network
Fast Update and Convergence
Support VLSM
Dividing the whole routing domain into different areas
Support Authentication
OSPF Features
OSPF for IPv6
Based on OSPFv2, with enhancements
Distributes IPv6 prefixes
Runs directly over IPv6
Ships-in-the-night with OSPFv2
OSPFv3
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGPs1. RIP2.
OSPF3. IS-IS
ISIS (Intermediate System to Intermediate System)
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 protocolMainly IPv6
What is ISIS
IS-IS has 2 levels of hierarchy◦ Level-1 (L1)
Neighbors only in the same AREA, and information about its own area
Hierarchy
L1 Adjacencies
R1R2
L1L1
R3
L1
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).
Why IS-IS?
InternetServiceProvider
TEIN3Network
User-A
User-B
Campus-A
Campus-B
Isb-PoP
Khi-PoP
Lhr-PoP
IGPs1. RIP2.
OSPF3. IS-IS
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) 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
ISIS and OSPF
Difference:
ISIS over OSPF
ISIS OSPFGenerally supports a up to 1024 nodes in the same Area
Generally deployed with a much smaller number of nodes (less than 200).
SPF table not refresh periodically. OSPF does so after 30min.
Provide more extensibility , for example ISIS was given new TLVs to Support IPv6.TLVs can also be utilize to carry MPLS TE attributes (ISIS-TE)
OSPF was completely re-written to Support IPv6 (i.e OSPFv3)
ISIS group update into one packet and send them as one LSP, so to increase network efficiency
OSPF produce many LSAs
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 “
ISIS over OSPF
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)
References
IS-IS
ISIS Cost (Core)
Legend
10G Link(Optic Fiber)
PSH-HECISB-HEC
LHR-HEC
KHI-HEC
MLT-BZU
QTA-BUITMS
HYD-USINDH
10G Link(Long Haul Fiber)
FSD-AUF
IS-IS enable interface
10
1010
10 10
10
10
10
10
1010
1010
10
1010
10
10
10
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
OSPF Design (PoP & Access)
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 L2VPNSubinterface20: Internet Subinterface30: NRENSubinterface40: Intranet
CPE:
.
One interlink ip
NAT and one default route pointing to NE20E
NMS Servers &Clients.
InternetServiceProvider
TEIN3Network
IS-IS BGP
OSPF
BGP(Border Gateway Protocol)
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
Border Gateway Protocol
Collection of networks with same routing policy Single routing protocol Usually under single ownership, trust and administrative control Identified by a unique number
Autonomous System (AS)
AS 100
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-numbers
Autonomous Number System (ASN)
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
Multi-homing
ISP-2 ISP-1
Multi-homed Customer
AS 100
Route Received
Prefix announcement Pre
fix announce
ment
Route R
eceived
EBGP & IBGP Implementation
ISP-2
ISP-1
PE
KHI-HEC-P-PE-EGRESS-NE80E
ISB-HEC-P-PE-EGRESS-NE80E
IBGPPEPE
PE
EBGP
EBGP
ISP-2
EBGP
ISP-1
EBGP
PERN2 BGP DESIGN
eBGP
peer
ing
ISP1
ASN-1
ISP2
ASN-2
eBGP peering
Full Ro
utin
g fe
ed R
eceive
d
Full Routing feed Received
Router Receives Full routing table from both ISP’s, and store the best available routes reveries from both these ISPs,
eBGP
peer
ing
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
Prefi
x's A
nnou
ncem
ent
Prefix's Announcement
BGP Policy routing has been applied, AS-PATH Prepend for the load balancing on Incoming traffic
eBGP
peer
ing
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
Prefi
x's A
nnou
ncem
ent
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
In Case of Link Failure
eBGP peering
Prefix's Announcement
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.
Conclusion
Customer Relationship Management (CRM) Service Communicator◦ Generates Tickets◦ http://sc.hec.gov.pk◦ 24/7 Help Line also Available i.e
111-11PERN 051-9040PERN
◦ Complain also can log by email [email protected]
THANKS