Enable Router on a Stick

BE

Router on a stick is a network topology that allows multiple VLANs to communicate with each other using a single physical interface on a router. In this topology, the router interface is divided into multiple logical subinterfaces, each of which is associated with a different VLAN. To enable router on a stick on a router subinterface, the following two steps must be performed:

1. Configure Encapsulation Dot1q: The first step is to configure the subinterface with the correct VLAN ID and enable encapsulation dot1q. This command tells the router to tag incoming traffic with the appropriate VLAN ID so that it can be forwarded to the correct VLAN. For example, if the subinterface is associated with VLAN 10, the following command would be used to configure encapsulation dot1q:

interface fa0/0.10 encapsulation dot1q 10

2. Configure the Subinterface with an IP Address: The second step is to configure the subinterface with an IP address and subnet mask. This address will be used as the default gateway for devices in the VLAN. For example, if the subinterface is associated with VLAN 10 and the network address is 192.168.10.0/24, the following command would be used to configure the IP address:

interface fa0/0.10 ip address 192.168.10.1 255.255.255.0

Note that options A, C, and D are not necessary to enable router on a stick on a router subinterface. Option A refers to configuring an IP route to the VLAN destination network, but this is only necessary if the router needs to route traffic to a remote network. Option C refers to configuring a default route, which is also not necessary for router on a stick. Option D refers to configuring full duplex and speed, which is a physical layer setting and not related to enabling router on a stick.