Verdict: the MikroTik CRS310-1G-5S-4S+IN is a suitable L3 gateway for internet connections up to 500Mbit/s!

Story

I saw this device and knew instantly its port configuration was perfect for my needs: mix of 1G/10G, SFP for labbing optical connections, and an RJ45 for WAN uplink.

Its routing capabilities are well-advertised as inferior to its switching capabilities. The CRS (Cloud Router Switch) name and its capability to run RouterOS mean it can operate at L3, but MikroTik advertises it as primarily a switch appliance. Its sister product, the netFiber 9 which runs the same hardware, is advertised as capable of “light routing”. Finally, the test results published by MikroTik show sub-1G L3 performance for all but the most optimal case. It is clear that I cannot expect line speed routing from the CRS310.

But, my home internet connection is 500Mbit/s. If the CRS310 can route at or above this speed, then it will be the perfect gateway device. Lets test it!!

Tests

I configured these parameters:

  • One bridge interface
  • No VLANs
  • IPv4 source-NAT for the local network
  • Eight IPv4 filter rules

I confirmed that the bridge is using the switch chip. Fast Path is OFF but Fasttrack is working.

Test 1: https://fast.com/ speed test
No fasttrack
Result: 260Mbit/s average with 3 samples

Test 2: https://fast.com/ speed test
Fasttrack for established,related packets on all interfaces
Result: 510Mbit/s average with 3 samples

Conclusions

MikroTik’s published test results for the CRS310 are realistic. It can route at L3 with a basic set of firewall rules and IPv4 source-NAT at least at ~500Mbit/s. I will be happy with this as my gateway :)

I did not inspect the packet sizes for the tests, so I cannot compare my results directly. My numbers fall between the 1518 byte and 512 byte reference numbers for fasttrack and 25 filter rules. I’m also using source-NAT which is not advertised to be a part of any of the reference results. Differences aside, it still felt like the published results gave a good-enough indicator of sub-1G but capable routing.

Bonus

Mikro-pic!