CNNA3-Chapter 6 docx

CCNA3-1
Chapter 6
Chapter 6
Chapter 6
Inter-VLAN Routing
Inter-VLAN Routing
CCNA3-2
Chapter 6
Inter-VLAN Routing
Inter-VLAN Routing
Introducing Inter-VLAN Routing
Introducing Inter-VLAN Routing
CCNA3-3
Chapter 6
•
What is Inter-VLAN Routing?
What is Inter-VLAN Routing?
•
Each VLAN is a
Each VLAN is a
unique broadcast domain
unique broadcast domain
.
.
•
Computers on separate VLANs are,
Computers on separate VLANs are,
by default
by default
, not
, not

able to communicate.
able to communicate.
•
Each VLAN is a
Each VLAN is a
unique IP subnetwork
unique IP subnetwork
.
.
•
To allow VLANs to communicate, we need a router to
To allow VLANs to communicate, we need a router to
communicate among separate broadcast domains and
communicate among separate broadcast domains and
unique IP subnetworks.
unique IP subnetworks.
•
Inter-VLAN routing
Inter-VLAN routing
, then,
, then,
is a process of forwarding traffic
is a process of forwarding traffic
from one VLAN to another VLAN using a router
from one VLAN to another VLAN using a router
.
.
Introducing Inter-VLAN Routing
Introducing Inter-VLAN Routing
CCNA3-4

Chapter 6
•
Methods:
Methods:
•
Traditional
Traditional
Inter-VLAN Routing.
Inter-VLAN Routing.
•
Router-on-a-stick
Router-on-a-stick
Inter-VLAN Routing.
Inter-VLAN Routing.
•
Switch Based
Switch Based
Inter-VLAN Routing.
Inter-VLAN Routing.
Introducing Inter-VLAN Routing
Introducing Inter-VLAN Routing
CCNA3-5
Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
•
One router interface per VLAN.
One router interface per VLAN.
Introducing Inter-VLAN Routing

Introducing Inter-VLAN Routing
VLAN
VLAN
Tagged
Tagged
VLAN
VLAN
Tagged
Tagged
Internally Routed to
Internally Routed to
the proper subnet.
the proper subnet.
Internally Routed to
Internally Routed to
the proper subnet.
the proper subnet.
Tag
Tag
removed
removed
Tag
Tag
removed
removed
CCNA3-6
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:

•
One router interface for
One router interface for
all VLANs
all VLANs
.
.
Introducing Inter-VLAN Routing
Introducing Inter-VLAN Routing
VLAN
VLAN
Tagged
Tagged
VLAN
VLAN
Tagged
Tagged
Internally Routed to
Internally Routed to
the proper subnet.
the proper subnet.
Internally Routed to
Internally Routed to
the proper subnet.
the proper subnet.
Tag
Tag
removed
removed
Tag

Tag
removed
removed
CCNA3-7
Chapter 6
•
Layer 3 Switch Inter-VLAN Routing:
Layer 3 Switch Inter-VLAN Routing:
•
Uses
Uses
Switch Virtual Interfaces (SVI)
Switch Virtual Interfaces (SVI)
to retag
to retag
the frame.
the frame.
Introducing Inter-VLAN Routing
Introducing Inter-VLAN Routing
VLAN
VLAN
Tagged
Tagged
(10)
(10)
VLAN
VLAN
Tagged
Tagged
(10)

(10)
Tag
Tag
removed
removed
Tag
Tag
removed
removed
CCNA3-8
Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
•
Traditional routing requires routers to have
Traditional routing requires routers to have
multiple
multiple
physical interfaces
physical interfaces
to facilitate inter-VLAN routing.
to facilitate inter-VLAN routing.
•
Each interface is also configured with an
Each interface is also configured with an
IP address for
IP address for
the subnet associated with the particular VLAN
the subnet associated with the particular VLAN

that it is
that it is
connected to.
connected to.
•
In this configuration, network devices can use the
In this configuration, network devices can use the
router
router
as a gateway
as a gateway
to access the devices connected to the
to access the devices connected to the
other VLANs.
other VLANs.
Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-9
Chapter 6
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
Interfaces and Subinterfaces
Interfaces and Subinterfaces
Tagged
Tagged
VLAN 10
VLAN 10
Tagged

Tagged
VLAN 10
VLAN 10
Tag
Tag
Removed
Removed
Tag
Tag
Removed
Removed
Router
Router
Responds
Responds
Router
Router
Responds
Responds
Routing table:
Routing table:
172.17.10.0 – F0/0
172.17.10.0 – F0/0
172.17.30.0 – F0/1
172.17.30.0 – F0/1
Routing table:
Routing table:
172.17.10.0 – F0/0
172.17.10.0 – F0/0
172.17.30.0 – F0/1

172.17.30.0 – F0/1
Router tags
Router tags
the frame
the frame
for VLAN 30
for VLAN 30
And switches it
And switches it
to Port F0/1.
to Port F0/1.
Router tags
Router tags
the frame
the frame
for VLAN 30
for VLAN 30
And switches it
And switches it
to Port F0/1.
to Port F0/1.
CCNA3-10
Chapter 6
Interfaces and Subinterfaces
Interfaces and Subinterfaces
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
Traditional Inter-VLAN Routing
CCNA3-11

Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
•
Traditional inter-VLAN
Traditional inter-VLAN
routing using physical
routing using physical
interfaces
interfaces
does have a
does have a
limitation
limitation
.
.
•
As the number of VLANs
As the number of VLANs
increases
increases
on a network, the
on a network, the
physical approach of having one router interface per
physical approach of having one router interface per
VLAN quickly becomes hindered by the physical
VLAN quickly becomes hindered by the physical
hardware limitations of a router.
hardware limitations of a router.

•
Routers have a limited number of physical interfaces
Routers have a limited number of physical interfaces
that
that
they can use to connect to different VLANs.
they can use to connect to different VLANs.
•
It is very expensive to add an Ethernet Interface.
It is very expensive to add an Ethernet Interface.
Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-12
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Subinterfaces:
Subinterfaces:
•
Overcomes the hardware limitation of a router.
Overcomes the hardware limitation of a router.
•
Subinterfaces are software-based virtual interfaces
Subinterfaces are software-based virtual interfaces
that are assigned to physical interfaces
that are assigned to physical interfaces
.
.

•
Each subinterface is configured with its
Each subinterface is configured with its
own IP
own IP
address, subnet mask, and unique VLAN assignment
address, subnet mask, and unique VLAN assignment
.
.
•
Connected to a
Connected to a
switch trunk link
switch trunk link
.
.
•
Functionally the same as using the traditional routing
Functionally the same as using the traditional routing
model.
model.
Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-13
Chapter 6
Interfaces and Subinterfaces
Interfaces and Subinterfaces
Router-on-a-stick Inter-VLAN Routing
Router-on-a-stick Inter-VLAN Routing
Router-on-a-stick Inter-VLAN Routing

Router-on-a-stick Inter-VLAN Routing
Tagged
Tagged
VLAN 10
VLAN 10
Tagged
Tagged
VLAN 10
VLAN 10
Tag
Tag
Removed
Removed
Tag
Tag
Removed
Removed
Routing table:
Routing table:
172.17.10.0 – F0/0.10
172.17.10.0 – F0/0.10
172.17.30.0 – F0/0.30
172.17.30.0 – F0/0.30
Routing table:
Routing table:
172.17.10.0 – F0/0.10
172.17.10.0 – F0/0.10
172.17.30.0 – F0/0.30
172.17.30.0 – F0/0.30
Tagged

Tagged
VLAN 30
VLAN 30
Tagged
Tagged
VLAN 30
VLAN 30
Tag
Tag
Removed
Removed
Tag
Tag
Removed
Removed
Tagged
Tagged
VLAN 30
VLAN 30
Tagged
Tagged
VLAN 30
VLAN 30
Tag
Tag
Removed
Removed
Tag
Tag
Removed

Removed
CCNA3-14
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Configuring Subinterfaces:
Configuring Subinterfaces:
•
Similar to configuring physical interfaces.
Similar to configuring physical interfaces.
•
Create the subinterface.
Create the subinterface.
•
Assign it to a VLAN.
Assign it to a VLAN.
•
Assign an IP Address.
Assign an IP Address.
•
Enable the interface.
Enable the interface.
Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-15
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:

Router-on-a-stick Inter-VLAN Routing:
•
Create the subinterface:
Create the subinterface:
•
The syntax for the subinterface is always the
The syntax for the subinterface is always the
physical
physical
interface
interface
, followed by a
, followed by a
period
period
and a
and a
subinterface
subinterface
number
number
.
.
•
The subinterface number is configurable, but it is
The subinterface number is configurable, but it is
typically associated to reflect the VLAN number
typically associated to reflect the VLAN number
.
.

R1(config)#
R1(config)#
interface
interface


[interface].nn
[interface].nn
NOTE:
NOTE:
The management VLAN must also be
The management VLAN must also be
configured if you wish to use it on multiple switches
configured if you wish to use it on multiple switches
that are not directly connected by trunk links.
that are not directly connected by trunk links.




Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-16
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Assign it to a VLAN:
Assign it to a VLAN:

•
Before assigning an IP Address, the interface must to
Before assigning an IP Address, the interface must to
be configured to operate
be configured to operate
on a specific VLAN
on a specific VLAN
using the
using the
proper
proper
encapsulation
encapsulation
.
.


R1(
R1(
config-subif
config-subif
)#
)#
encapsulation dot1q
encapsulation dot1q


vlan-id
vlan-id
Interfaces and Subinterfaces

Interfaces and Subinterfaces
CCNA3-17
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Assign an IP Address:
Assign an IP Address:
•
The IP Address assigned here will become the
The IP Address assigned here will become the
default
default
gateway
gateway
for that VLAN.
for that VLAN.


R1(
R1(
config-subif
config-subif
)#
)#
ip address
ip address
[address] [mask]
[address] [mask]

Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-18
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Enable the interface:
Enable the interface:
•
Subinterfaces are not enabled individually.
Subinterfaces are not enabled individually.
•
When the physical interface is enabled,
When the physical interface is enabled,
all associated
all associated


subinterfaces
subinterfaces
are enabled.
are enabled.


R1(
R1(
config-if
config-if

)#
)#
no shutdown
no shutdown
Interfaces and Subinterfaces
Interfaces and Subinterfaces
CCNA3-19
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Configuring Subinterfaces:
Configuring Subinterfaces:
Interfaces and Subinterfaces
Interfaces and Subinterfaces
VLAN 10
VLAN 10
VLAN 10
VLAN 10
VLAN 10
VLAN 10
VLAN 10
VLAN 10
VLAN 30
VLAN 30
VLAN 30
VLAN 30
VLAN 10
VLAN 10

VLAN 10
VLAN 10
VLAN 30
VLAN 30
VLAN 30
VLAN 30
Enable Interfaces
Enable Interfaces
Enable Interfaces
Enable Interfaces
CCNA3-20
Chapter 6
•
Router-on-a-stick Inter-VLAN Routing:
Router-on-a-stick Inter-VLAN Routing:
•
Configuring Subinterfaces:
Configuring Subinterfaces:
Interfaces and Subinterfaces
Interfaces and Subinterfaces
Planning!
Planning!
Planning!
Planning!
CCNA3-21
Chapter 6
•
Router Interface and Subinterface Comparison:
Router Interface and Subinterface Comparison:
Interfaces and Subinterfaces

Interfaces and Subinterfaces
CCNA3-22
Chapter 6
Inter-VLAN Routing
Inter-VLAN Routing
Configuring Inter-VLAN Routing
Configuring Inter-VLAN Routing
(Putting It All Together)
(Putting It All Together)
CCNA3-23
Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
Configuring Inter-VLAN Routing
Configuring Inter-VLAN Routing
CCNA3-24
Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
Configuring Inter-VLAN Routing
Configuring Inter-VLAN Routing
CCNA3-25
Chapter 6
•
Traditional Inter-VLAN Routing:
Traditional Inter-VLAN Routing:
Configuring Inter-VLAN Routing
Configuring Inter-VLAN Routing