Inter-VLAN routing Chapter 6

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Inter-VLAN routingChapter 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
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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

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Traditional inter-VLAN routing
Router looks up 192.168.2.0 network port F0/1
Router sends out packet through F0/1 to
switchport F0/2
3.
Send packet to F0/0 of router
ARP request to find MAC address of default gateway
2.
Switchport F0/2 is on VLAN30 and forwards to PC3.
4.
PC1 has a packet for 192.168.2.19 different
subnet
1.
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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 routers
  interface?
• In which configuration mode is this done?
• To overcome the hardware limitations of
  inter-VLAN 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
• Create VLANs
• VLANs assigned to the switch ports
• For Router-on-a-stick configuration,
  _________________
• Router 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