Download Routing

Chapter 7
 Upon
completion of this chapter, you should
be able to:
 Configure a router with basic settings
 Describe the routing process
 Read a routing table
 Configure static & default routes
 Describe routing protocols RIP, EIGRP, OSPF
 Configure OSPF
 Describe NAT
 Configure NAT & Port Forwarding
WAN Serial
Ports in slot
LAN
interfaces
Console
Port RJ45
AUX
Port RJ45
LAN
Interfaces in slot
7.1
 Moves
packets from one network to another
 Finds
the best path to destination based on
destination IP & SM
 Checks
its routing table
 Directly
connected- YOU’RE IN!
 Remote
networks- LEARN IT!


Static entry- YOU TYPE IN
Dynamic entry- ROUTING PROTOCOL EXCHANGES
INFO BETWEEN ROUTERS
 After

it learns all routes IN your network-
Converged!
 How
do you get OUT of your network?
 Create
 For



a default route (special static route)
default route, use quad zero
0.0.0.0 0.0.0.0
IP
SM
Means ANY
 No
default route= Most likely no
communication outside your network
 Router
forwards packet to a destination
network


Looks at routing table to see which port to go out
You can set a default route to go out if
destination network is not in routing table
Default route
using
outgoing INT
Default route
using
outgoing
next hop IP
 Show

ip route
Stored in RAM
 How
it was learned
 When it was updated
 Which interface to use to get to that network
192.168.10.0/24
.10
PC1
10.1.1.0/24
G0/0
.1
.1
R1
.1
G0/1
.10
PC2
.10
209.165.200.224 /30
192.168.11.0/24
.225
S0/0/0
.226
R2
.10
.1
10.1.2.0/24
R1#show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
D
D
C
L
C
L
C
L
R1#
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
10.1.1.0/24 [90/2170112] via 209.165.200.226, 00:00:05, Serial0/0/0
10.1.2.0/24 [90/2170112] via 209.165.200.226, 00:00:05, Serial0/0/0
192.168.10.0/24 is variably subnetted, 2 subnets, 3 masks
192.168.10.0/24 is directly connected, GigabitEthernet0/0
192.168.10.1/32 is directly connected, GigabitEthernet0/0
192.168.11.0/24 is variably subnetted, 2 subnets, 3 masks
192.168.11.0/24 is directly connected, GigabitEthernet0/1
192.168.11.1/32 is directly connected, GigabitEthernet0/1
209.165.200.0/24 is variably subnetted, 2 subnets, 3 masks
209.165.200.224/30 is directly connected, Serial0/0/0
209.165.200.225/32 is directly connected, Serial0/0/0
 What
do you configure in a router to tell it
“if you don’t have the destination network in
the routing table, go this way.”

Default route
 What
are the 2 possible commands to
configure a default route?


B(config)# ip route 0.0.0.0 0.0.0.0 next hop IP
B(config)# ip route 0.0.0.0 0.0.0.0 outgoing int
 What

does the quad zero mean?
Any network (IP/SM)
 Which

command encrypts all passwords?
Service password-encryption
 You

telling the router:
“To get to this network, go this way!”
 Used
so routers do less “thinking” or when
there’s only one way out of a network

Stub networks or small networks
 Same
as default route config, but replacing
quad zero with destination network address

ip route destination_network subnet mask next hop ip or
outgoing int

R1(config) #ip route 192.168.16.0 255.255.255.0
192.168.15.1
What would be the
static route on R2
to reach the ladies’
network?
 TestOut
7.1.1- Routing
 TestOut
7.1.3- Practice Questions (5)
 TestOut
7.2.3- Configure Static Routes
 Handout:
Create static routes
 Complete
the PT lab together

Configure default and static routes
7.2
 Each

private network is identified by an AS #
Given by your ISP
 They
 IGP



(Interior Gateway Protocol)
Shares routing info WITHIN the AS
Most common you’ll work with
 EGP

share routing information
(Exterior Gateway Protocol)
Shares routing info BETWEEN AS
Internet routing
 Metrics



Method of choosing the best path
Hops, throughput, delay, load, reliability, etc.
Lowest metric- best route!
 Distance
Vector
 Link-State
7.2.1
 Maintain



tables when changes occur
Bad cables, interfaces go down, better route
learned
Best route to a network in table
Removes routes when no longer valid
 When
all routers agree on topology=
converged
 Two routers can exchange these tables as
long as they use the same protocol
 Passes
updates every so often to connected
neighbors
 Distance & Direction

Metric (hops, speed, reliability, etc)
 Directly
connected network has an
administrative distance of 0
 Neighbors update each other & add on how far
away it is
Star is 2
away
Star is 1
away
Star is 0
away
Star is 2
away
 Handout


Distance Vector Routing Tables Using Hops
Do together on SmartBoard
 Create


a Diagram from Routing Tables
On paper
In groups of 2, create a topology based on
Routing Table
7.2.1
 Knows
all routes in your network
 Sends out LSAs at start
 Makes a Topological database

With info from LSAs
 Uses



the SPF algorithm
Each change causes new calc & database update
Map of network from point of view of the router
Info in tree is used to build the routing table
 Adds
best path to each destination to routing
table
 Then only sends change updates
 Hybrid

Uses both DV & LS
 Using


Most current routing protocols send subnet mask
info
They are called Classless Routing Protocols
 No

VLSM in your network?
subnet mask info sent?
These are called Classful Routing Protocols
7.2.3
 DV
IGP
 Metric is Hops

Only15 Max; 16 is unreachable (D)
 Updates



every 30 seconds by default
Sends entire routing table (D)
If change, update sent immediately (triggered)
Slow to converge whole network (D)
 Administrative
Distance is 120
 RIPv1


Doesn’t send subnet mask in updates
Classful subnetting
 RIPv2



Classless (VLSM) subnetting
Supports authentication
Otherwise, same as v1
 Increased
 Max

traffic every 30 seconds
hop count of 15
Further away is unreachable
 Only
considers hops, not speed
 Possible
routing loops
 What
routing protocol uses hops for its
metric and understands classless routing?

RIPv2
 What

is the AD of RIP?
120
 What’s
the purpose of entering your router’s
network numbers when configuring RIP?

To tell it what networks to advertise in updates
A
directly connected network has an AD of…

A

0
static route has an AD of…
1
7.2.3
 Enhanced






Interior Gateway Routing Protocol
Hybrid IGP (mix LS & DV)
AD of 90
Many metrics (bandwidth, delay, load, reliability)
Up to 255 hops
Updates on start of router & only when a change
happens
VLSM Support
7.2.3
 Most
popular routing protocol
 LS IGP


Sends updates only when the topology changes
Does not send periodic updates of the entire
routing table
 AD
of 110
 Metric is cost (bandwidth)
 Fast convergence, no loops
 Supports VLSM/classless addressing
 OSPF

Keeps the map of network smaller if you break it
up into areas
 By

default you will always have a single area
Normally this is area 0
 You

works with the concepts of areas
can have multiple areas
They all connect to area 0 (the backbone)

See picture…
7.2.3
 Configure







StudentCenter Router:
Hostname- StudentCenter
Enable password- cisco
Secret password- class
Con 0 & vty password- gcit
Encrypt all passwords
Se0/0/0- 192.168.12.1 /24
Se0/0/1- 192.168.13.1 /24
 Configure
ScienceBuilding Router
 Configure AdminBuilding Router









ScienceBuilding(config)#router ospf 1
ScienceBuilding(config-router)#network
192.168.23.0 0.0.0.255 area 0
ScienceBuilding(config-router)#network
192.168.12.0 0.0.0.255 area 0
AdminBuilding(config)#router ospf 1
AdminBuilding(config-router)#network
192.168.23.0 0.0.0.255 area 0
AdminBuilding(config-router)#network
192.168.13.0 0.0.0.255 area 0
Also configure StudentCenter
Process ID
Wildcard mask
Think of a wildcard mask as the inverse of a
subnet mask.
 The inverse of the subnet mask 255.255.255.252
is 0.0.0.3.
 To calculate the inverse of the subnet mask,
subtract the subnet mask from 255.255.255.255:

255.255.255.255
– 255.255.255.252
0. 0. 0. 3
Subtract the sm
Wildcard mask
 StudentCenter#Show

ip route
Views the routing table
 StudentCenter#show
ip ospf neighbor
 AdminBuilding#show
ip protocols
 AdminBuilding#show
ip route ospf
7.2.3
 Border



Gateway Protocol
Exterior gateway protocol
Used for sharing routes on the Internet
Supports VLSM
 TestOut
7.2.7- Enable OSPF Routing
 TestOut
7.2.8- Practice Questions (15)
7.3
 Allows


Use private inside your network
Use one/few public for outside access
 Used

you to save public IP addresses
on your border/gateway router
Home & school
CLASS
A
B
C
PRIVATE IP ADDRESS RANGE

Static NAT
One to one mapping; AKA Port Forwarding
 A particular INSIDE PRIVATE IP always translates to the
SAME PUBLIC IP
 Use: Email Server on the inside that outside people
need to access


PAT/NAT Overload
Port Address Translation
 Many-to-one mapping
 Many INSIDE PRIVATE IP’s translated to ONE PUBLIC
(most common at home)
 Keeps track using source port #’s

 Dynamic





NAT
Many to many mapping
Has a pool of public IP addresses to choose from
More for getting out rather than getting in
Translates the private IP to one of the public IPs
& awaits a response
After session is closed, the public IP is returned
to the pool of public addresses
 Which
type of NAT maps many private IP
addresses to one public IP, like in your home
network?


PAT or NAT Overload
You have a web server at work hosting your
work website. It’s behind your firewall & has
a private IP address. Which type of NAT will
allow people outside of your network to
access it?

Static NAT
7.3.2
7.3.4
 Your
device MUST have a static IP address
 Example:




You have an IP camera
You want to access it from anywhere
Assign it 192.168.0.190
Use port forwarding to allow communication to
go through only using a certain port
 Do



this in Packet Tracer
Add WRT300 in Wireless Devices
Applications & Gaming Tab
Port 8090; TCP; for 192.168.0.190
 11.2.4.4
Packet Tracer - Configuring Port
Forwarding on a Linksys Router
 TestOut
7.3.6- Practice Questions (11)
 Which
statement describes NAT overload or
PAT?




Each internal address is dynamically translated
to an individual external IP address.
A single internal address is always translated to
the same external IP address.
Many internal addresses are translated to a single
IP address using different port numbers.
Many internal addresses are statically assigned a
single IP address and port.
7.5
 TestOut
7.5.4- Find Path Information 1
 TestOut
7.5.5- Find Path Information 2
 Complete
the study guide handout
 Complete
TestOut
 Practice
in Packet Tracer
 Jeopardy
review
Chapter 7