Download Ethernet

Inter-VLAN routing
Chapter 6
CCNA Exploration Semester 3
Modified by Profs. Ward
and Cappellino
1
Topics



Routing network traffic between VLANs
Configuring a router for routing between
VLANs
Troubleshoot inter-VLAN connectivity issues
2
Semester 3
LAN Design
Basic Switch
Concepts
VLANs
VTP
Wireless
STP
Inter-VLAN
routing- Ch 6
3
Inter VLAN routing
Switch keeps VLANs
separate
• _________________
_______________
Router can _____________
____________________
• allows devices
connected to different
VLANs to communicate
Inter-VLAN routing is a __________________________
_______________________________________________
4
__________ 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
6
Inter-VLAN routing using
____________________

What about creating a
trunk link to the
router?

A _______________
___________________
___________________
7
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 ____________________________
8
Router-on-a-Stick cont…



R1 F0/0 has
subinterfaces, one
for each VLAN.
Each has its own
IP address.
VLAN tags on
trunk.
9
Availability of trunking

Not all routers allow subinterfaces for VLAN
trunking on Ethernet ports.

It depends on the IOS feature set.
10
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…
11
_________________ 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
12
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
13
Routing table

Subinterfaces are shown
14
Router Interface vs. Subinterface
15
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
16
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
17