cnap 3 01 introduction vlsm

7/27/2019 Cnap 3 01 Introduction VLSM

1/31

The

SaigonCTT

1

CNAP Semester 3: Switching Basics and

Intermediate Routing

Module 1

Introductionto

Classless Routing

Version 3.0Cisco Regional Networking Academymailto: [email protected]


2/31

The

SaigonCTT

2

Objectives

Define VLSM and briefly describe the reasons for its use Divide a major network into subnets of different sizes using

VLSM

Define route aggregation and summarization as they relate

to VLSM Configure a router using VLSM

Identify the key features of RIP v1 and RIP v2

Identify the important differences between RIP v1 and RIP

v2 Configure RIP v2

Verify and troubleshoot RIP v2 operation

Configure default routes using the ip route and ip default-

network commands


3/31

The

SaigonCTT

3

Table of Content

1 VLSM2 RIP version 2


4/31

The

SaigonCTT

4

VLSM


5/31

The

SaigonCTT

5

Issues with IP Addressing

IP addressing crisis

As early as 1992, the IETF identified two specificconcerns:

IP address exhaustion

Routing table growth

U N I V E R S I T YU N I V E R S I T Y

Internet


6/31

The

SaigonCTT

6

IP Addressing Solutions

Short term to extension to IPv4

Subneting masking: RFCs 950, 1812

Variable-length subnet masks: RFC 1812

Classless interdomain routing: RFCs 1518, 1519,2050

Address allocation for private Internets: RFC

1918 NetworkAddress Translation: RFC 1631

Route summarization: RFC 1518

Ultimate solution: IPv6 128-bit address space


7/31

The

SaigonCTT

7

172.16.14.32/27

172.16.14. 64/27

172.16.14.96/27

What is VLSM ?

Subnet 172.16.14.0/24 is divided into smallersubnets (Sub-subnet):

Subnet with one mask at first (/27)

Further subnet one of these subnets not usedelsewhere (/30)

C

B

A

HQHQ172.16.0.0/16


8/31

The

SaigonCTT

8

VLSM is supported

Open Shortest Path First (OSPF).

Integrated Intermediate System to Intermediate

System (Integrated IS-IS). Enhanced Interior Gateway Routing Protocol

(EIGRP).

RIP v2. Static routing.


9/31

The

SaigonCTT

9

A waste of space


10/31

The

Saigon

CTT

10

When to use VLSM?


11/31

The

Saigon

CTT

11

Calculating subnets with VLSM


12/31

The

Saigon

CTT

12

Calculating subnets with VLSM (2)

Derived from the

172.16.32.0/20 Subnet172.16.33.0/30

172.16.32.0/26

172.16.32.64/26

172.16.32.128/26

172.16.32.192/26

26-Bit Mask (62 Hosts)

Derived from the

172.16.33.0/26 Subnet

30-Bit Mask (2 Hosts)

172.16.33.12/30

172.16.33.8/30

172.16.33.4/30


13/31

The

Saigon

CTT

13

Exercise Calculating subnets with VLSM

60 Hosts 12 Hosts 12 Hosts

Using VLSMs, define appropriate subnets foraddressing the networks using 192.168.10.0/24.

28 HostsKL

SydneyPerth Singapore


14/31

The

Saigon

CTT

14

Exercise Calculating subnets with VLSM

60 Hosts 12 Hosts 12 Hosts

192.168.10.0/24

KL

SydneyPerth Singapore

192.168.10.64/27

192.168.10.128/30192.168.10.132/30 192.168.10.136/30

28 Hosts

192.168.10.0/26 192.168.10.96/28 192.168.10.112/28


15/31

The

Saigon

CTT

15

Route aggregation with VLSM

KLSydney

Perth

Singapore

192.168.48.0/24192.168.49.0/24192.168.50.0/24192.168.51.0/24

192.168.52.0/24

192.168.53.0/24192.168.54.0/24192.168.55.0/24

192.168.56.0/24

192.168.57.0/24192.168.63.0/24

192.168.52.0/22

192.168.48.0/22

UpstreamproviderUpstreamprovider

Route summarization reduces routing table size byaggregating routes to multiple networks into onesupernet


16/31

The

Saigon

CTT

16

Route summarization example


17/31


18/31

The

Saigon

CTT

18

RIP Version 2


19/31

The

Saigon

CTT

19

RIP v1: Characteristics

IGP protocol, is classful routing. It is a distance vector protocol that uses a hop

count metric.

The maximum number of hops is 15. By default, routing updates are broadcast every 30

seconds.

The router applies the one subnet mask that isconfigured on the receiving interface to receivenetwork information.

Load balancing over as many as six equal-cost

paths, with four paths as the default.


20/31

The

Saigon

CTT

20

RIP v1: Limitations

It does not send subnet mask information in itsupdates.

It sends updates as broadcasts on255.255.255.255.

It does not support authentication.

It is not able to support VLSM or classlessinterdomain routing (CIDR).


21/31

The

SaigonC

TT

21

RIP v1: Configuration

NOTE:

Subnets will be understood as major network


22/31

The

SaigonC

TT

22

RIP v2 features

Send out subnet mask information with the routeupdate.

Support VLSM or classless interdomain routing (CIDR).

Provides for authentication in its updates.

Provides Multicast routing updates, using the ClassD address 224.0.0.9.

Use external route tags

Routing update is includes a next-hop route ipaddress.


23/31


24/31

The

SaigonC

TT

24

RIP v2: Configuration

router rip

version 2

network 150.100.0.0

router rip

version 2

network 150.100.0.0

Kuala Lumpur Bangkok

150.100.4.0/24

150.100.2.0/24

150.100.3.0/24

NOTE:

Assigning IP network numbers without specifying subnet

values


25/31

The

SaigonC

TT

25

Verifying RIP v2 : SHOW IP PROTOCOLS

BA

172.16.1.1

192.168.1.0172.16.1.0

10.1.1.1 10.1.1.2 10.2.2.2 10.2.2.3 192.168.1.1

B


26/31

The

SaigonC

TT

26

Verifying RIP v2: SHOW IP ROUTE

BA

172.16.1.1

192.168.1.0172.16.1.0

10.1.1.1 10.1.1.2 10.2.2.2 10.2.2.3 192.168.1.1

B


27/31

The

SaigonC

TT

27

Troubleshooting RIP v2 : DEBUG IP RIP

BA

172.16.1.1

192.168.1.0172.16.1.0

10.1.1.1 10.1.1.2 10.2.2.2 10.2.2.3 192.168.1.1

B


28/31

The

SaigonC

TT

28

Default routes

InternetInternet


29/31

The

SaigonC

TT

29

Summary

VLSM and the reasons for its use

Subnetting networks of different sizes using VLSM

Route aggregation and summarization as theyrelate to VLSM

Router configuration using VLSM

Key features of RIP v1 and RIP v2

Important differences between RIP v1 and RIP v2

Configuration of RIP v2

Verifying and troubleshooting RIP v2 operation

Configuring default routes using theip routeandi default-networkcommands


30/31

The

SaigonC

TT

30

Q&A


31/31

The

SaigonC

TT

1

cnap 3 01 introduction vlsm

Documents