Transcript Ethernet
Inter-VLAN routing
Chapter 6
CCNA Exploration Semester 3
Modified by Profs. Ward
and Cappellino
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Topics
Routing network traffic between VLANs
Configuring a router for routing between
VLANs
Troubleshoot inter-VLAN connectivity issues
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Semester 3
LAN Design
Basic Switch
Concepts
VLANs
VTP
Wireless
STP
Inter-VLAN
routing- Ch 6
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Inter VLAN routing
Switch keeps VLANs
separate
• _________________
_______________
Router can _____________
____________________
• allows devices
connected to different
VLANs to communicate
Inter-VLAN routing is a __________________________
_______________________________________________
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__________ inter-VLAN routing
The router and switch both have
__________________________________
___________________ of the router has an
_________________________________
Routing is the same as routing between any
subnets.
See next slide for example…
5
Traditional inter-VLAN routing
3. Router
Router looks
sendsup
out
packet to
2. Send
ARP request
to
F0/0
of router
find MAC
address
of default gateway
192.168.2.0
network
–
packet through
F0/1 to
port
F0/1 F0/2
switchport
4. Switchport F0/2 is
on VLAN30 and
forwards to PC3.
1. PC1 has a
packet for
192.168.2.19
– different
subnet
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Inter-VLAN routing using
____________________
What about creating a
trunk link to the
router?
A _______________
___________________
___________________
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Inter-VLAN routing using
Router-on-a-Stick cont…
"Router-on-a-stick" is a type of router
configuration in which __________________
____________________________________
________________________________
The _____________ is configured to operate as a
_____________ and is connected to a ________
_____________________________
Each VLAN needs a different IP address.
Use ____________, each with its own IP address.
Subinterfaces are multiple ______________, associated
with ____________________________
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Router-on-a-Stick cont…
R1 F0/0 has
subinterfaces, one
for each VLAN.
Each has its own
IP address.
VLAN tags on
trunk.
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Availability of trunking
Not all routers allow subinterfaces for VLAN
trunking on Ethernet ports.
It depends on the IOS feature set.
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Router Interface Configuration
Recall how to program an IP address on a
router’s interface?
In which configuration mode is this done?
To overcome the hardware limitations of interVLAN routing based on router physical
interfaces…
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_________________ are used
A subinterface is _________________________________
_________________________________________
Subinterface is represented by: the _______________ followed
by __________________________
It is normal to _______________________. If this ties in with the
IP address, even better.
Ex: interface f0/0.10
Might be associated with subnet 192.17.10.0
Each subinterface has it own IP address.
The physical interface has no IP address
The ________________________________
Issue the “no shutdown” command
Then ____ subinterfaces off that physical interface are enabled
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Configuring subinterfaces
R1(config)#interface f0/0.10
R1(config-subif)#encapsulation dot1q 10
R1(config-subif)#ip address 172.17.10.1
255.255.255.0
(add any other subinterfaces)
R1(config-subif)#interface f0/0
R1(config-if)#no shutdown
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Routing table
Subinterfaces are shown
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Router Interface vs. Subinterface
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Configuration
When configuring Inter-VLAN routing, the _______
________________, _____________________
Switch configuration
Router configuration
Create VLANs
VLANs assigned to the switch ports
For Router-on-a-stick configuration, _________________
Configure interfaces (__________ for Router-on-a-stick)
including ip addresses, encapsulation, no shutdown etc
Use _______ commands, ping and tracert to verify
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Troubleshooting
Check physical connections
Check switchport VLAN assigment
Check trunking on switches
Check IP addressing and subnetting scheme
in relation to VLANs
Check router subinterface configuration
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