In this tutorial, we are going to set up a medium sized LAN with 3 VLANS spanning
a campus network. The scenario will illustrate how you would connect multiple workgroup switches & route between VLANs. The following is a diagram illustrating how we are going to interconnect the core layer 3 switch with the 3 workgroup switches.
Typically, by default, the vlan1 (layer 3) interface is already in the Cisco switch configuration. In this particular design, you should administratively shut down the interface.
Make sure you assign the correct VLAN to the access ports that are cabled up to client's workstations. The default per-port setting (vlan 1) will not work in this environment.
Notice this design is slightly different then the one in tutorial 6. This is because we had one subnet / VLAN per workgroup switch. In this mode, we had end users that are connected to two different workgroup switches that need to be on the same VLAN / subnet. This means that we need to configure trunking since we
are using one dedicated uplink to the core & multiple VLANs are attached to workgroup switch 1 & 3. In addition, we configure both layer 2 VLANS & layer
3 VLAN interfaces. Here’s the configuration:
| SYNTAX | DESCRIPTION |
| layer 3 switch | |
| conf t | Enter global configuration mode |
| vlan 10 | Creates (layer 2) VLAN 10 |
| vlan 20 | Creates (layer 2) VLAN 20 |
| vlan 30 | Creates (layer 2) VLAN 30 |
| exit | Leaves vlan-config mode |
| interface f0/1 | Enter interface-config mode |
| switchport mode trunk | Changes port from access to trunk port |
| interface f0/2 | Enter interface-config mode |
| switchport access vlan 20 | Assigns port to VLAN 20 |
| interface f0/3 | Enter interface-config mode |
| switchport mode trunk | Changes port from access to trunk port |
| exit | Leaves inerface-config mode |
| interface vlan10 | Creates Layer 3 VLAN interface |
| ip address 10.1.1.1 255.255.255.0 | Assigns IP address to interface (gateway address for VLAN 10) |
| no shut | Enables interface |
| interface vlan20 | Creates layer 3 VLAN interface |
| ip address 10.1.2.1 255.255.255.0 | Assigns IP address to interface (gateway address for VLAN 20) |
| no shut | Enables interface |
| interface vlan30 | Creates layer 3 VLAN interface |
| ip address 10.1.3.1 255.255.255.0 | Assigns IP address to interface (gateway address for VLAN 30) |
| no shut | Enables interface |
| SYNTAX | DESCRIPTION |
| workgroup switch 1 | |
| conf t | Enter global configuration mode |
| vlan 10 | Creates (layer 2) VLAN 10 |
| interface vlan10 | Creates layer 3 VLAN interface |
| ip address 10.1.1.2 255.255.255.0 | Assigns IP address to switch for management |
| no shut | Enables interface |
| interface f0/1 | Enter interface-config mode |
| switchport mode trunk | Changes port from access to trunk port |
| exit | Return to global-config mode |
| ip default-gateway 10.1.1.1 | Creates default route for management purposes |
| SYNTAX | DESCRIPTION |
| workgroup switch 2 | |
| conf t | Enter global configuration mode |
| vlan 20 | Creates (layer 2) VLAN 20 |
| Interface vlan20 | Creates layer 3 VLAN interface |
| ip address 10.1.2.2 255.255.255.0 | Assigns IP address to switch for management |
| no shut | Enables interface |
| interface f0/1 | Enter interface-config mode |
| switchport access vlan 20 | Assigns uplink port to VLAN 20 Do the same for every user port that will be off VLAN 20 |
| exit | Return to global-config mode |
| ip default-gateway 10.1.2.1 | Creates default route for management purposes |
| SYNTAX | DESCRIPTION |
| workgroup switch 3 | |
| conf t | Enter global configuration mode |
| vlan 30 | Creates (layer 2) VLAN 30 |
| interface vlan30 | Creates layer 3 VLAN interface |
| ip address 10.1.3.2 255.255.255.0 | Assigns IP address to switch for management |
| no shut | Enables interface |
| interface f0/1 | Enter interface-config mode |
| switchport mode trunk | Changes port from access to trunk port |
| exit | Return to global-config mode |
| ip default-gateway 10.1.3.1 | Creates default route for management purposes |
