Configuring Layer 3 switching and Inter-VLAN routing.
I will start by configuring the interfaces for the Internet routers and
the switches.
On Internet-1
# conf t
# hostname Internet-1
# int g0/0
# ip address 209.165.200.226 255.255.255.252
# no shut
# int s0/0/0
# ip address 10.1.1.1 255.255.255.252
# no shut
On Internet-2
# conf t
# hostname Internet-2
# int s0/0/1
# ip address 10.1.1.2 255.255.255.252
# no shut
Next, we will configure the switches:
On SW-1:
# conf t
# hostname SW-1
# vlan 99
# int vlan 99
# ip address 172.16.99.10 255.255.255.0
# exit
# ip default-gateway 172.16.99.254
# int range g0/1, f0/10, f0/5
# switchport mode trunk
# switchport trunk native vlan 50
# no shut
# vlan 10
# vlan 20
# vlan 30
On SW-2:
# conf t
# hostname SW-2
# vlan 99
# int vlan 99
# ip address 172.16.99.20 255.255.255.0
# exit
# ip default-gateway 172.16.99.254
# int f0/10
# switchport mode trunk
# switchport trunk native vlan 50
# vlan 10
# vlan 20
# vlan 30
# int f0/1
# switchport mode access
# switchport access vlan 10
# int f0/2
# switchport mode access
# switchport access vlan 20
# int f0/3
# switchport mode access
# switchport access vlan 30
# no shut
On SW-3:
# conf t
# vlan 99
# int vlan 99
# ip address 192.168.99.30 255.255.255.0
# int f0/10
# switchport mode trunk
# switchport trunk native vlan 50
# vlan 10
# vlan 20
# vlan 30
# int f0/1
# switchport mode access
# switchport access vlan 30
# int f0/2
# switchport mode access
# switchport access vlan 20
# int f0/3
# switchport mode access
# switchport access vlan 10
# no shut
A multilayer switch is capable of both Layer 2 switching and Layer 3
Routing, one of the advantages of using a multilayer switch is this
dual functionality, a benefit for a small-to medium-sized company
would be the ability to purchase a single multilayer switch instead of
separate switching and routing network devices, capabilities of a
multilayer switch include the ability to route from one VLAN to
another using multiple switched virtual interface (SVI), as well as the
ability to convert a layer 2 switchport to a layer 3 interface.
At first, we will configure the G0/2 port on the MLS as a routed port
that you can ping another layer 3 address.
On the MLS:
# conf t
# hostname MLS
# int g0/2
# no switchport
# ip address 209.165.200.225 255.255.255.252
# no shut
Let us verify by pinging G0/0 on Internet-1 router.
# ping 209.165.200.226 it should be successful
Next, we will configure Inter-VLAN Routing:
I will add VLANs to MLS
VLAN 10, VLAN 20 , VLAN 30 and VLAN 99
On MLS:
# conf t
# vlan 10
# vlan 20
# vlan 30
Configure SVI on MLS:
I will configure and activate the SVI “ Switched Virtual Interface” for
VLANs, 10, 20, 30 and 99
# int vlan 10
# ip address 172.16.10.254 255.255.255.0
# no shut
# int vlan 20
# ip address 172.16.20.254 255.255.255.0
# no shut
# int vlan 30
# ip address 172.16.30.254 255.255.255.0
# no shut
# int vlan 99
# ip address 172.16.99.254 255.255.255.0
# no shut
Next, I will enable Routing, but first I will run this show command to
see if the routing is enabled or not
On MLS:
# show ip route it doesn’t look it
Enable the routing
# ip routing
Let us verify that routing is enabled
# show ip route it is enabled.
Next, we will verify end to tend connectivity
On PC-A Ping PC-3 or MLS to verify connectivity within VLAN 10
On PC-A:
# ping 172.16.10.20
On PC-B ping PC-2 or MLS to verify connectivity with VLAN 20
On PC-2:
# ping 172.16.20.20
From PC-C ping PC-1 or MLS to verify connectivity within VLAN 30
On PC-C:
# ping 172.16.30.20
From SW-1, Ping SW-2 or SW-3 or MLS to verify connectivity with
VLAN 99.
On SW-1:
# ping 172.16.99.20
# ping 172.16.99.254
To verify inter-VLAN routing, ping devices outside the sender’s VLAN
On PC-A:
# ping 172.16.30.20.
From any device, Ping the address inside cloud 209.165.200.226