A Single Trunk Link

A Single Trunk Link
Another possible solution to routing between VLANs is creating a trunk link on a switch and
then using a frame-tagging protocol such as ISL or 802.1Q (which are used to identify VLAN/
frame relationships as they traverse FastEthernet and Gigabit Ethernet links) on the router.
Cisco calls this solution “router on a stick.”
Figure 17.2 shows how the internetwork might look with a single trunk link for all VLANs.