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I have a 951G-2HnD as a router. All connections are via ethernet cables. I observe the following:

  1. When I connect to the ISP via router, speed is about 270 Mbit/s, while ISP claims my plan has 500 Mbit/s speed limit.
  2. When I connect cable from ISP directly to ethernet port on my PC, I indeed get about 500 Mbit/s download speed.
  3. When I download files from another PC connected to the same router, the speed is about 900 Mbit/s which is correct for gigabit LAN.

Now because of 3, I think that the problem is not in router processing power. I suppose something is wrong with NAT processing. How do I improve speed so NAT connection is as fast as direct one? Or at least how do I debug the problem?

Just in case, I disabled all NAT rules except the main one:

/ip firewall nat chain=srcnat action=masquerade out-interface=ether1-gateway

This did not improve the speed.

Dessa Simpson
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Uprooted
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2 Answers2

16

The 951G-2HnD has a rated peak routing speed of 250-300Mbps. It does its switching in hardware and should be able to switch at wire speed. So it sounds like you're getting roughly the performance the hardware is capable of.

David Schwartz
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6

David's answer is correct. To summarize, the hardware is capable of switching at the speed you got, but only routing at a fraction of that. Therefore, the problem is the routing, not just the NAT, although that probably doesn't help.

Take a look at these results for routers that should be capable of routing that much traffic:

https://mikrotik.com/product/RB750Gr3#fndtn-testresults

https://mikrotik.com/product/RB3011UiAS-RM#fndtn-testresults

Any of these three should be enough unless you're doing a large amount of very small packet routing.

Another possibility is the CHR product - you can run your router in a VM and give it as much CPU and RAM as you need. $30 covers the cost for a 1Gbps cap.

EDIT: Somehow https://mikrotik.com/product/hap_ac2#fndtn-testresults has better results than the 3011 for non-full-size packets despite having significantly less CPU and RAM, and being on the same architecture.

Dessa Simpson
  • 1,776