Code : STM#520-1 Samsung Electronics Co., Ltd. OfficeServ7400 Router Operation Distribution Englis h ED01
Dec 28, 2015
Code : STM#520-1Code : STM#520-1
Samsung Electronics Co., Ltd.
OfficeServ7400 Router OperationOfficeServ7400 Router Operation
Distribution
EnglishED01
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ObjectivesObjectives
After successful completion of the course the trainees should be able to execute the following activities.
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ContentsContents
Layer 3 Routing OverviewLayer 3 Routing Overview
Routing ConfigurationRouting Configuration
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Layer 3 Routing OverviewLayer 3 Routing Overview
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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.
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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
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IGP and EGPIGP and EGP
Popular routing protocols
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Autonomous systemsAutonomous systems
Interior routingInterior routing Exterior routingExterior routing
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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
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Routing informationRouting information
Administrative distance
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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
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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
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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
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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
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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
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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
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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.
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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
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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)
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RIPRIP
Routing update
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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
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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
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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.
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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
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OSPFOSPF
OSPF Message Format
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OSPFOSPF
Hierarchical RoutingConsists of areas and autonomous systems
Minimize routing update traffic
Area 0
Area 1 Area 2
Autonomous System
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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
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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
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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
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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
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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
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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
network 130.140.1.0 area 2
area 2 virtual-link 130.150.1.1
Router D
router ospf 100
network 130.140.1.0 area 2
network 130.150.1.0 area 3
area 2 virtual-link 130.140.1.1
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ConfigurationConfiguration
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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
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Configure Static RouteConfigure Static Route
Static Route command & statusFor static route using Input Configuration Command
Current Configuration Status
add static route
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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 #3 configuration router rip version 2 (or version 1) network 172.16.0.0/24 redistribute connected
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 #3 configuration router rip version 2 (or version 1) network 172.16.0.0/24 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
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Configure RIPConfigure RIP
RIP command and status
Example) Configuration of OS7400 #3
-. RIP version 2
-. Redistribute Connected route
(address of Network Interface)
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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 #3 configuration router ospf network 172.16.0.0/24 area 0 redistribute connected
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 #3 configuration router ospf network 172.16.0.0/24 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
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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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