In my review a couple of years ago of the Linksys RV042, I noted the RV042's support for multiple LAN subnets, but was disappointed the RV042 didn't support 802.1q VLAN tagging. Even the newer Cisco WRV210 doesn’t support 802.1q tagging. So it's nice to see the RV 120W supports 802.1q VLANs.
On the RV 120W, VLAN IDs can be assigned from 1-4094, with up to four active VLANs. With VLANs enabled, multiple subnets are created, one per VLAN. In addition, the RV 120W will create a DHCP server for each subnet. Finally, each port on the RV 120W can be configured as access, general, or trunk.
An access port on the RV 120W is a member of a single VLAN. A general port on the RV 120W is useful when connecting to a VoIP device. If a VoIP device is connected to a general port on the RV 120W, and the VoIP device supports tagging and has a PC connected to it, the untagged traffic from the PC connected to the VoIP device will be assigned to the port's VLAN ID, separate from the VoIP VLAN. Finally, a trunk port on the RV 120W can connect to another VLAN capable device that supports 802.1q trunking.
To test access ports, I added VLAN 2 to the RV 120W and configured port 2 to be an access port on VLAN 2, I noticed the router automatically created a new subnet, 192.168.2.0/24 for VLAN 2, different from the default subnet of 192.168.1.0/24. Figure 10 shows the subnets assigned to each VLAN. I connected a PC to port 2 and it received an IP address from the 192.168.2.0/24 subnet, as expected.
Figure 10: VLAN subnets
To test trunking, I configured port 3 on the RV 120W to be a trunk and a tagged member of both VLAN 1 and 2. I then connected port 3 of the RV 120W to port 3 of the recently reviewed LG ES-2026 smart switch. On the LG, I configured port 1 as a member of VLAN 1, port 2 as a member of VLAN 2, and port 3 as a trunk. I was pleased to see a PC connected to port 1 on the LG got an IP in the 192.168.1.0/24 subnet from the RV 120W, and a PC connected to port 2 on the LG got an IP in the 192.168.2.0/24 subnet from the RV 120W, validating 802.1q trunking/tagging.
The VLAN functionality of the RV 120W is not limited to just wired networks. It is also useful with wireless networks, which I'll describe next.
The RV 120W has a flexible single-band 802.11b/g/n wireless radio that supports up to four different wireless networks. Each wireless network can have a different SSID which can be hidden or broadcast. Further, each RV 120W wireless network can utilize different security protocols (WEP, WPA, WPA2), and can be a member of a different VLAN.
The RV 120W can also be configured to support 802.1X authentication using an external RADIUS server for devices on both the LAN and WLAN.
Having multiple wireless SSIDs is pretty useful. A hidden, private and secure wireless network can be set up for internal use. A separate, open wireless network can be set up for guest access. Additional wireless networks can be set up for other purposes. Since each wireless network can be on a different VLAN, traffic from each wireless network can be filtered by the firewall. For example, a network administrator could block guest wireless clients from secure areas of the network.
I did some basic tests, enabling multiple access points on the RV 120W and assigned each to a different VLAN. I configured each access point with a different VLAN and different security setting, as shown in Figure 11.
Figure 11: Multi-SSID configuration
I was able to use my Window 7 laptop to connect to each of the different SSIDs. I entered the appropriate security code for WEP, WPA, or WPA2 and was able to surf.
Bandwidth controls on the RV 120W are pretty granular. Bandwidth controls can be applied to outbound traffic flows based on traffic types.
Profiles are created to define traffic priority (low, medium, or high) or rate limits based on minimum and maximum bandwidth values. Finally, Traffic Selectors are created where profiles are applied to traffic types based on the IP addresses, MAC address, RV 120W port, VLAN, DSCP code, or wireless LAN.
To test, I used my previously created custom traffic type for iperf. I set up a profile with a traffic limit of 100-1000 Kbps, and applied my profile to iperf traffic originated from VLAN 1.
Figure 12: Bandwidth rate limiting
Figure 12 shows a screen shot of the profile I created, and Figure 13 shows the Traffic Selector I created to apply my profile.
Figure 13: Traffic selector
I then ran a few iperf tests, again using the defaults as described in my VPN testing. With the above selector disabled, my iperf throughput was over 50 Mbps. With the above selector in place, my iperf throughput was limited to 912 Kbps, pretty close to the 1000 Kbps limit I set, proving the selector limited the desired traffic when enabled. In short, bandwidth management worked as expected.
If you want to prioritize traffic instead of apply rate limits, the RV 120W supports 802.1p traffic prioritization. This feature uses traffic marking based on CoS and DSCP values and assigns traffic to low, medium or high priority queues. VoIP traffic, which is often assigned CoS value = 5, and/or DSCP value = 46, could be assigned to the high priority queue to ensure that it always gets through.
Last, the RV 120W supports traffic metering. Some ISPs are going to a metered service, where if your network utilization exceeds a certain amount, you can be charged by the MB for the overage, similar to the pricing model of many 3G and 4G WWAN services. The RV 120W allows for metering and blocking traffic if your Internet usage exceeds anywhere up to 99,999 MB per month. Even if you don't want to limit your traffic, enabling this feature in unlimited mode allows you to measure your monthly outgoing and incoming traffic volume by MB.