Mikrotik CRS309-1G-8S+IN

Initial impressions on a very energy efficient 10Gbps SFP+ switch and an excellent choice for a VMware home lab!

A little over a year ago I decided to get my lab 10Gbps capable. At the time, the Quanta LB6M seemed like the obvious choice with 24x SFP+ interfaces, several 1Gbps copper interfaces and a price tag of only $300 USD. It worked well in my lab, but as you can imagine, older 10Gbps technology is far from energy efficient. The switch idled at close to 130W, which wasn’t far off from all three of my compute hosts put together. It was also very loud with seven high-RPM 40mm fans. Even when at their lowest setting, these chassis and PSU fans were painfully loud. There is no doubt that this switch is more at home in a datacenter than a home lab. It wasn’t long before I started keeping an eye out for newer offerings based on more efficient and cost-effective technologies. That’s when I came across Mikrotik’s latest 3xx series “Cloud Router Switches”.

The Mikrotik CRS309-1G-8S+IN

Mikrotik is a technology firm based out of Latvia and is well known for their unique networking products. They sell a range of switches, routers, wireless products and even their caseless RouterBOARD systems for those interested in doing custom routers.

I was originally looking to purchase the CRS309’s bigger brother – the CRS317. Feature-wise they are very similar, but the CRS317 doubles up on SFP+ and 1Gbps copper interfaces. With two SFP+ ports on each of my four ESXi hosts, the CRS309’s eight SFP+ ports seemed to be sufficient. The feature that sold me on the CRS309 as opposed to the CRS317, however, was its completely passive/fanless design. The CRS317’s fans only spin up if the unit gets hot, but I liked the simplicity of a completely fanless solution.

Feature-wise, the CRS309 is a pretty impressive switch. Its state of the art Marvel Prestera 98DX8208 switching chip (98DX8216 in the CRS317) is what makes this such an efficient unit. The 98DX8208 is highly integrated and is good for line rate forwarding on all the SFP+ ports. It also includes an integrated dual core 32-bit ARM based processor running 800MHz. You can find more information on the Marvel Prestera here. The flash storage is a pretty spartan 16MB, but this seems to be plenty for the RouterOS and SwOS firmware to coexist on the switch simultaneously. I’ll get more into the CRS309’s software in a future post.

From a L2 perspective, it’s a perfectly capable unit. It can do line-rate L1 and L2 forwarding at about 81,000Mbps aggregate, or 162,000 Mbps full-duplex. This is because the 98DX8208 has an ASIC switching component and all L2 forwarding is done in hardware. The L3 features of the switch, however, are all done in software and must be processed by the integrated ARM CPU cores. Based on Mikrotik’s test results, about 2.5Gbps can be expected when traffic has to go through the CPU. Your mileage may vary though depending on the features you use. This may not sound great, but in a home lab environment, you don’t really need high throughput for inter-VLAN routing or other L3 features. I’m most interested in having 10Gbps line rate throughput for host-to-host VSAN traffic, iSCSI, vMotion etc. If you really do need faster routing, you could always spin up a VyOS VM and use your hypervisor’s horsepower for that purpose. Given the $269 USD price of the unit, I think it’s awesome that you get a full suite of L3 features even if throughput is somewhat limited.

You can find more information and the specifications of the CRS309 at Mikrotik’s site.

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