Chapter 7. Breaking the VLAN barrier by using switched virtual interfaces
Although splitting devices into separate virtual LANs (VLANs) prevents excessive flooding and provides a bit of security, it creates another problem: devices in separate VLANs can’t communicate with each other—at least not without a little help.
At the end of the last chapter, I recommended connecting two test computers to the two VLAN access ports you configured. If you weren’t able to do that, don’t worry. You can still follow along with most of the exercises, and I’ll provide screenshots to fill in the gaps, using the computers shown in figure 7.1 as an example.
As you can see, HR-PC1 is connected to FastEthernet0/20, which is an access port in VLAN 600, and Executive-PC1 is connected to FastEthernet0/21, which is in VLAN 700. As it stands, these two devices can’t communicate with each other. In fact, they can’t communicate with any devices outside their respective VLANs. Creating new VLANs and setting up access ports was the first step, but you need to do more before you can actually start using these new VLANs.
In this chapter, I’m going to teach you how to get these two computers talking to each other using a feature called switched virtual interfaces (SVIs).