Like every other website on the planet, SmallNetBuilder uses cookies. Our cookies track login status, but we only allow admins to log in anyway, so those don't apply to you. Any other cookies you pick up during your visit come from advertisers, which we don't control.
If you continue to use the site, you agree to tolerate our use of cookies. Thank you!

Router Charts

Click for Router Charts

Router Ranker

Click for Router Ranker

NAS Charts

Click for NAS Charts

NAS Ranker

Click for NAS Ranker

More Tools

Click for More Tools

LAN & WAN Basics


VLANs or Virtual LANs are another way of implementing network security by controlling broadcast traffic. Since network broadcasts are used by ARP to match up MAC and IP addresses, if you control broadcast traffic, you control the ability of devices to communicate.

Most smart switches allow you to set up VLANs either based on physical ports or using the 802.1Q protocol. Using 802.1Q adds VLAN information to packets so that VLANs can be created across multiple switches and even subnets. For single-switch LANs, you can use port-based VLANs, as shown in Figure 4. Note that VLANs don't create multiple subnets, so all devices will still be on whatever subnet that your router's DHCP server assigns.

Settting up port-based VLANs

Figure 4: Settting up port-based VLANs

Using port-based VLANs, it's simple to set up a "Guest" VLAN that allows Internet access, but no access to other LAN clients. Unfortunately, the GS108T's GUI shows VLAN membership for only one VLAN ID at a time. So Figure 5 is actually a composite that I created from two screenshots.

Guest VLAN port assignment

Figure 5: Guest VLAN port assignment

The "Guest" port 4 and the switch uplink port 8 (which connects out to my LAN's router) are assigned to VLAN 2 and port 4 is also removed from VLAN 1. Since the uplink port is a member of both VLANs, the computer connected to port 4 can connect out to the Internet, but can't connect to any devices connected to the other GS108T switch ports.

That's it for this time. The next and last installment will show you how to use a smart switch to control client bandwidth use.

More Basics

Wi-Fi System Tools
Check out our Wi-Fi System Charts, Ranker and Finder!

Support Us!

If you like what we do and want to thank us, just buy something on Amazon. We'll get a small commission on anything you buy. Thanks!

Over In The Forums

Just curious as to why the vertical axis on the 24-hour traffic analyser is not set to display the data better...View attachment 20951
So here goes a long one. I’m only posting this to let people know the progress I’m on for my @lifx bulbs.the problem... opening the app and lost contr...
since going to 384.14_2 I lose wireless sometimes and have to reboot the router. always comes back after reboot. wired connections fine. this is the f...
[Oops. I just discovered the Security>VPN subforum. I guess this post should be moved there.]If anybody is successfully running a Windows Remote Deskt...
Is there any way to end a DHCP lease from the router? I have an active DHCP lease for a device that keeps renewing; even though that device hasn't bee...

Don't Miss These

  • 1
  • 2
  • 3