1. Chapter 6 1 Chap 6 – Implement Inter-VLAN Routing Learning Objectives Explain to the satisfaction of a qualified instructor how network traffic is routed between VLANs in a converged network. Configure inter-VLAN routing on a router to enable communications between end-user devices on separate VLANs Troubleshoot common inter-VLAN connectivity issues.

2. Chapter 6 2 Inter-VLAN Routing Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 Inter-VLAN routing can be performed by connecting different physical router interfaces to different physical switch ports. The switch ports connect to the router in access mode, and different static VLANs are assigned to each port interface. Each switch interface would be assigned to a different static VLAN. Each router interface can then accept traffic from the VLAN associated with the switch interface that it is connected to, and traffic can be routed to the other VLANs connected to the other interfaces. R1 Link to VLAN 20 Link to VLAN 30 Link to VLAN 10

3. Chapter 6 3 Router-on-a -Stick Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 R1 R1 - Fa0/0 Sub-interfaces Fa0/0.10 – 172.17.10.1 – Default Gateway to VLAN 10 Fa0/0.20 – 172.17.20.1 – Default Gateway to VLAN 20 Fa0/0.30 – 172.17.30.1 – Default Gateway to VLAN 30 Fa0/0 "Router-on-a-stick" is a type of router configuration in which a single physical interface routes traffic between multiple VLANs on a network. Sub-interfaces are configured for different subnets corresponding to their VLAN assignment to allow logical routing before data frames are VLAN tagged and sent back out the physical interface. Sub-interfaces are multiple virtual interfaces, associated with one physical interface. These sub-interfaces are configured with an IP address and VLAN assignment to operate on a specific VLAN.

4. Chapter 6 4 Layer-3 Switch Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3 Fa0/4 Fa0/2Fa0/3 S1 VLAN Interfaces 172.17.10.1 – Default Gateway to VLAN 10 172.17.20.1 – Default Gateway to VLAN 20 172.17.30.1 – Default Gateway to VLAN 30 Some switches can perform Layer 3 functions, replacing the need for dedicated routers to perform basic routing on a network. Multilayer switches are capable of performing inter-VLAN routing. To enable a multilayer switch to perform routing functions, VLAN interfaces on the switch need to be configured with the appropriate IP addresses that match the subnet that the VLAN is associated with on the network. The multilayer switch also must have IP routing enabled.

5. Chapter 6 5 Management VLAN 99 172.17.99.10/24 Student VLAN 20 172.17.20.22/24 Student VLAN 20 172.17.20.25/24 Guest VLAN 30 172.17.30.26/24 Guest VLAN 30 172.17.30.23/24 Fa0/1 Fa0/3 Fa0/18 Fa0/6 Connecting VLANs SVI VLAN20 SVI VLAN30 SVI VLAN99 Layer 3 Switch Switch Virtual Interface (SVI) is a logical interface configured for a specific VLAN, and is used by layer 3 switches to route between VLANs or to provide IP host connectivity to a switch. A Layer 3 switch has the ability to route transmissions between VLANs. The process is the same as when using a separate router, except that the SVIs act as the router interfaces for routing the data between VLANs.

6. Chapter 6 6 Physical Interface Configuration Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 R1 Fa0/0 172.17.10.1/24 Fa0/1 172.17.30.1/24 Configure Router Interfaces Fa0/6Fa0/5

7. Chapter 6 7 Sub-Interface Configuration Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 R1 Fa0/0.10 172.17.10.1/24 Fa0/0.30 172.17.30.1/24 Configure Router Interfaces To avoid confusion, name the sub- interface after the VLAN to which it is attached – e.g. Fa0/0.10 is connected to VLAN 10 Fa0/5

8. Chapter 6 8 Sub-Interface Configuration Fa0/1 S2 PC1 172.17.10.21/24 (VLAN 10) Fa0/11 PC2 172.17.20.22/24 (VLAN 20) PC3 172.17.30.23/24 (VLAN 30) Fa0/18 S3S1 Fa0/1 Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 R1 Fa0/0.10 172.17.10.1/24 Fa0/0.30 172.17.30.1/24 Fa0/5 S1 Fa0/5 must be configured as a trunk to allow it to carry tagged data from multiple VLANs

9. Chapter 6 9 Interface and Sub-Interface Comparison

10. Chapter 6 10 Chap 6 – Implement Inter-VLAN Routing Learning Objectives Explain to the satisfaction of a qualified instructor how network traffic is routed between VLANs in a converged network. Configure inter-VLAN routing on a router to enable communications between end-user devices on separate VLANs Troubleshoot common inter-VLAN connectivity issues.

11. Chapter 6 11 Any Questions?

12. Chapter 6 12 Lab Topology PC1 172.17.10.10/24 Fa0/11 PC3 172.17.30.10/24 Chap 6.2.2.4 – Basic Inter-VLAN Routing Fa0/8Fa0/5 Fa0/6 R1 Fa0/0Fa0/1

13. Chapter 6 13 Lab Topology PC1 172.17.10.10/24 Fa0/11 PC3 172.17.30.10/24 Chap 6.2.2.5 – Router- On-A-Stick Inter-VLAN Routing Fa0/5 Fa0/6 R1 Fa0/1

14. Chapter 6 14 Lab Topology Fa0/1 S2 PC1 172.17.10.21/24 Fa0/11 PC2 172.17.20.22/24 PC3 172.17.30.23/24 Fa0/18 S3S1 Fa0/1 Chap 6.4.1 – Basic VLAN Routing Fa0/6 Fa0/2 Fa0/3 Fa0/1 Fa0/4Fa0/3Fa0/4 Fa0/2Fa0/3 R1 Server 172.17.50.254/24 Fa0/0 Fa0/1 172.17.50.1