Code : STM#520-1 Samsung Electronics Co., Ltd. OfficeServ7400 Router Operation Distribution EnglishED01

Code : STM#520-1Code : STM#520-1

Samsung Electronics Co., Ltd.

OfficeServ7400 Router OperationOfficeServ7400 Router Operation

Distribution

EnglishED01

© Samsung Electronics Co., Ltd. 2

ObjectivesObjectives

After successful completion of the course the trainees should be able to execute the following activities.


ContentsContents

Layer 3 Routing OverviewLayer 3 Routing Overview

Routing ConfigurationRouting Configuration


Layer 3 Routing OverviewLayer 3 Routing Overview


OverviewOverview

IntroductionStatic routing is fine if the network is small, there is a single connection point to other networks, and there are no redundant routes. If any of these conditions is false, dynamic routing is normally used.

Look at the dynamic routing protocols used by routers to communicate with each other.


IGP and EGPIGP and EGP

IGP (Interior Gateway Protocol) Routing protocol to communicate between the routers in each AS.

RIP (Routing Information Protocol)

OSPF (Open Shortest Path First)

EGP (Exterior Gateway Protocol)Routing protocols that are used between the routers in different ASs.

BGP (Border Gateway Protocol)

ASASASAS

IGPIGP IGPIGP

EGPEGP


IGP and EGPIGP and EGP

Popular routing protocols


Autonomous systemsAutonomous systems

Interior routingInterior routing Exterior routingExterior routing


Routing informationRouting information

Example

R : How the route was learned (RIP)172.16.8.0 : Destination logical network or subnet120 : Administrative distance/2 : Metric Value00:00:23 : Age of entryeth0 : Outgoing interface

MetricIf there are multiple paths within the AS from a router to a network, the router selects the path with the smallest hop count.

RIP : Hop CountsOSPF : Bandwidth, Cost, ….

R 172.16.8.0 [120/2] via 172.16.7.9, 00:00:23, eth0


Routing informationRouting information

Administrative distance


Static Route (example)Static Route (example)

130.100.1.1/24

130.120.1.1/24

130.120.1.2/24 130.130.1.1/24130.130.1.2/24

130.140.1.1/24

130.140.1.2/24

130.150.1.1/24

130.150.1.2/24

B

A

C

D

E

e1

e0

e0s0 s0

e0 e0

e1

e1

Router B

ip route 130.100.1.0 255.255.255.0 130.120.1.1 ip route 130.140.1.0 255.255.255.0 130.130.1.2 ip route 130.150.1.0 255.255.255.0 130.130.1.2


RIPRIP

Use UDP datagram

UDP datagram Format

Metric: Hop Counts

Hop Count’s limit : 15

IP header UDP header RIP message

20 bytes 8 bytes


RIPRIP

is based on distance vector routing, which uses the Bellman-Ford algorithm for calculating the routing tables.

Distance Vector Routingeach router periodically shares its knowledge about the entire internet with neighbors

the operational principles of this algorithm

Sharing knowledge about the entire autonomous system

Sharing only with neighbors

Sharing at regular intervals (ex, every 30 seconds)

Distance Vector Routing Table


RIPRIP

RIPv1 message format

Command(1-6) Version(1) (must be zero)

Address family(2) (must be zero)

32-bit IP address

(must be zero)

(must be zero)

Metric(1-16)

(up to 24 more routes, with same format as previous 20 bytes)

Command : request (1) or response (2)Version of RIPv1 : 1Address : destination network addressDistance : defining the hop count from the advertising router to the destination network


RIPRIP

RIPv2 message format

command(1-6) Version(2) routing domain

address family(2) Routing tag

32-bit IP address

32-bit subnet mask

32-bit next-hop IP address

metric(1-16)

(up to 24 more roues, with same format as previous 20 bytes)

20bytes

Route Tag : carrying information such as the autonomous system number Subnet mask : carrying the subnet mask Next-hop address : showing the next hop


RIPRIP

Timers in RIPPeriodic timer : controlling the advertisements of regular update messages

Expiration timer : governing the validity of a route

The garbage collection timer : advertising the failure of a route

Periodic timer Controlling the advertising of regular update messages

Using random number between 25 to 35 seconds


RIPRIP

Expiration timerIn normal situation, the new update for a route occurs every 30 seconds

But, if there is a problem on an Internet and no update is received within the allotted 180 seconds, the route is considered expired and the hop count of the route is set to 16.

Each router has its own expiration timer.

Garbage Collection TimerWhen the information about a route becomes invalid, the router continues to advertise the route with a metric value of 16 and the garbage collection timer is set to 120 sec for that route

When the count reaches zero, the route is purged from the table.


RIPRIP

Timer Example A routing table has 20 entries. It does not receive information about five routes for 200 seconds. How many timers are running at this time?

The timers are listed below:Periodic timer: 1

Expiration timer: 20 - 5 = 15

Garbage collection timer: 5


RIPRIP

Routing update

255.255.255.255255.255.255.255

255.255.255.255

RIPv1(Broadcast)

224.0.0.9224.0.0.9

RIPv2(Multicast)


RIPRIP

Routing update


RIPRIP

RIP (Example)

130.100.1.1/24

130.120.1.1/24

130.120.1.2/24 130.130.1.1/24130.130.1.2/24

130.140.1.1/24

130.140.1.2/24

130.150.1.1/24

130.150.1.2/24

B

A

C

D

E

e1

e0

e0s0 s0

e0 e0

e1

e1

Router A

router rip

network 130.100.1.0/24

network 130.120.1.0/24

Router B

router rip

network 130.120.1.0/24

network 130.130.1.0/24

Router D

router rip

network 130.140.1.0/24

network 130.150.1.0/24

Router E

router rip

network 130.150.1.0/24

Router C

router rip

network 130.130.1.0/24

network 130.140.1.0/24


OSPFOSPF

CharacteristicsIn a distance-vector protocol, each router sends and receives the messages which contain a vector of distances. (hop counts)

In a link-state protocol, each router actively tests the status of its link to each of its neighbors, sends this info. to its other neighbors, which then propagate it throughout the AS.

From a practical perspective, the important difference is that a link-state protocol will always converge faster than a distance vector protocol.

Area 0

Area 1 Area n

Backbone routerArea border router

Internal router


OSPFOSPF

Features that make OSPF superior to RIPOSPF can calculate a separate set of routes for each IP type-of-service.

Each interface is assigned a dimensionless cost.(throughput, RTT, etc.)

Load balancing: When several equal-cost routes to a destination, OSPF distributes traffic equally among the routes.

OSPF supports subnets.

Point-to-point links bet’n routers do not need an IP addr. at each end.

A simple authentication scheme can be used.

OSPF uses multicasting instead of broadcasting.


OSPFOSPF

RIP vs OSPFFunction/Feature RIPv1 RIPv2 OSPF

Standard number RFC 1058 RFC 1723 RFC 2178

Link-state protocol No No Yes

Large range of metrics Hop count(16 = infinity) Hop count(16 = infinity) Yes, based on 1-65,535

Update policyRouting table every 30

secondsRouting table every 30

secondsWhen link state change

Or every 30 minutes

Update address Broadcast Broadcast, multicast multicast

Dead interval 300 seconds total 300 seconds total Variable settings

Supports authentication No Yes Yes

Convergence timeMedia delay +Dead interval

Variable(based on Number of routers * DI)

Variable(based on Number of router * DI)

Variable-length subnets NO Yes Yes

Type of service(TOS) NO NO Yes

Network diameter 15 hops 15 hops 65,355 possible


OSPFOSPF

OSPF Message Format


OSPFOSPF

Hierarchical RoutingConsists of areas and autonomous systems

Minimize routing update traffic

Area 0

Area 1 Area 2

Autonomous System


OSPFOSPF

The Backbone and Virtual LinksBackbone center of communication

Virtual link provide path to backbone

Avoid configuring virtual link if possible

Area 0Area 1

Area 2

Area 3


OSPFOSPF

Link-State DB & AdvertisementLink-State DB

represents the network topologyshared with OSPF routers in same area

LSA (Link-State Advertisement)sourced by router connected to linkflooded by all other routers in areatransmitted at each link-state change

LSA


OSPFOSPF

Link-State Advertisement Operation

LSALSA

LSA

LSA receivedIs entry intopologicaldatabase

reset timer for entry

add to database

flood LSA

run SPF to caculatenew table

Y

N


OSPFOSPF

Type of Link-State Packets

router

network

summary

external

ABR ASBR

externalASO - OSPF derived intra-area (router)

IA - inter-area (summary)E1 - type 1 externalE2 - type 2 external

OSPF routing table


OSPFOSPF

Configuration Example

130.100.1.1/24

130.120.1.1/24

130.120.1.2/24 130.130.1.1/24

130.140.1.1/24

130.140.1.2/24

130.150.1.1/24

130.150.1.2/24

B

A

C

D

E

e1

e0

e0s0 s0

e0 e0

e1

e1

Router B

router ospf

network 130.130.1.0/24 area0

network 130.120.1.0/24 area1

Router C

router ospf

network 130.130.1.0/24 area0

network 130.140.1.0/24 area2

Router D

router ospf

network 130.140.1.0/24 area2

network 130.150.1.0/24 area2

Area 1

Area 0Area 2


OSPFOSPF

Virtual Link Example

130.100.1.1/24

130.120.1.1/24

130.120.1.2/24 130.130.1.1/24130.130.1.2/24

130.140.1.1/24

130.140.1.2/24

130.150.1.1/24

130.150.1.2/24

B

A

C

D

E

e1

e0

e0s0 s0

e0 e0

e1

e1

Area 1

Area 0Area 2

Area 3

Router C

router ospf 100

network 130.130.1.0 area 0


area 2 virtual-link 130.150.1.1

Router D

router ospf 100



area 2 virtual-link 130.140.1.1


ConfigurationConfiguration


Configure Static RouteConfigure Static Route

ConfigurationConfigure routing entry using static route.

We can use Default GW option of Interface

Network

165.213.100.0

165.213.89.238

165.213.89.237

ip route 165.213.100.0 255.255.255.0 165.213.89.238

or

ip route 165.213.100.0/24 165.213.89.238


Configure Static RouteConfigure Static Route

Static Route command & statusFor static route using Input Configuration Command

Current Configuration Status

add static route


Configure RIPConfigure RIP

Configuration

10.0.0.0/24

OS7400 #1 192.168.30.0/24 OS7400 #2 172.16.0.0/24

30.0.0.0/24PC #2

30.0.0.100

OS7400 #3

OS7400 #1 configuration router rip version 2 (or version 1) network 192.168.30.0/24 redistribute connected

OS7400 #2 configuration router rip version 2 (or version 1) network 172.16.0.0/24 network 192.168.30.0/24 redistribute connected



OS7400 #2 configuration router rip version 2 (or version 1) network 172.16.0.0/24 network 192.168.30.0/24 redistribute connected


OS7400 #2 Routing TableR>* 10.0.0.0/8 [120/2] via 192.168.30.1, eth0, 00:01:23R>* 30.0.0.0/8 [120/2] via 172.16.0.2, eth1, 00:02:02C>* 127.0.0.0/8 is directly connected, loC>* 172.16.0.0/24 is directly connected, eth1C>* 192.168.30.0/24 is directly connected, eth0

OS7400 #3 Routing TableR>* 10.0.0.0/8 [120/3] via 172.16.0.1, eth0, 00:03:09C>* 30.0.0.0/24 is directly connected, eth1C>* 127.0.0.0/8 is directly connected, loC>* 172.16.0.0/24 is directly connected, eth0R>* 192.168.30.0/24 [120/2] via 172.16.0.1, eth0, 00:01:08

OS7400 #2 Routing TableR>* 10.0.0.0/8 [120/2] via 192.168.30.1, eth0, 00:01:23R>* 30.0.0.0/8 [120/2] via 172.16.0.2, eth1, 00:02:02C>* 127.0.0.0/8 is directly connected, loC>* 172.16.0.0/24 is directly connected, eth1C>* 192.168.30.0/24 is directly connected, eth0

OS7400 #3 Routing TableR>* 10.0.0.0/8 [120/3] via 172.16.0.1, eth0, 00:03:09C>* 30.0.0.0/24 is directly connected, eth1C>* 127.0.0.0/8 is directly connected, loC>* 172.16.0.0/24 is directly connected, eth0R>* 192.168.30.0/24 [120/2] via 172.16.0.1, eth0, 00:01:08


Configure RIPConfigure RIP

RIP command and status

Example) Configuration of OS7400 #3

-. RIP version 2

-. Redistribute Connected route

(address of Network Interface)


Configure OSPFConfigure OSPF

Configuration

PC #1

10.0.0.100

10.0.0.0/24

OS7400 #1192.168.30.0/24 OS7400 #2 172.16.0.0/24

30.0.0.0/24PC #2

30.0.0.100

OS7400 #3

OS7400 #1 configuration router ospf network 192.168.30.0/24 area 0 redistribute connected

OS7400 #2 configuration router ospf network 172.16.0.0/24 area 0 network 192.168.30.0/24 area 0 redistribute connected



OS7400 #2 configuration router ospf network 172.16.0.0/24 area 0 network 192.168.30.0/24 area 0 redistribute connected


OS7400 #2 Routing TableO>* 10.0.0.0/24 [110/20] via 192.168.30.1, eth0, 00:04:21O>* 30.0.0.0/24 [110/20] via 172.16.0.2, eth1, 00:02:22C>* 127.0.0.0/8 is directly connected, loO 172.16.0.0/24 [110/10] is directly connected, eth1, 00:04:22C>* 172.16.0.0/24 is directly connected, eth1O 192.168.30.0/24 [110/10] is directly connected, eth0, 00:04:22C>* 192.168.30.0/24 is directly connected, eth0

OS7400 #3Routing TableO>* 10.0.0.0/24 [110/20] via 172.16.0.1, eth0, 00:02:31C>* 30.0.0.0/24 is directly connected, eth1C>* 127.0.0.0/8 is directly connected, loO 172.16.0.0/24 [110/10] is directly connected, eth0, 00:03:10C>* 172.16.0.0/24 is directly connected, eth0O>* 192.168.30.0/24 [110/74] via 172.16.0.1, eth0, 00:02:32

OS7400 #2 Routing TableO>* 10.0.0.0/24 [110/20] via 192.168.30.1, eth0, 00:04:21O>* 30.0.0.0/24 [110/20] via 172.16.0.2, eth1, 00:02:22C>* 127.0.0.0/8 is directly connected, loO 172.16.0.0/24 [110/10] is directly connected, eth1, 00:04:22C>* 172.16.0.0/24 is directly connected, eth1O 192.168.30.0/24 [110/10] is directly connected, eth0, 00:04:22C>* 192.168.30.0/24 is directly connected, eth0

OS7400 #3Routing TableO>* 10.0.0.0/24 [110/20] via 172.16.0.1, eth0, 00:02:31C>* 30.0.0.0/24 is directly connected, eth1C>* 127.0.0.0/8 is directly connected, loO 172.16.0.0/24 [110/10] is directly connected, eth0, 00:03:10C>* 172.16.0.0/24 is directly connected, eth0O>* 192.168.30.0/24 [110/74] via 172.16.0.1, eth0, 00:02:32


Configure OSPFConfigure OSPF

OSPF command and status

Example) Configuration of OS7400 #3 -. OSPF area 0 -. Redistribute connected route (address of Network Interface)

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Code : STM#520-1 Samsung Electronics Co., Ltd. OfficeServ7400 Router Operation Distribution EnglishED01