Where is my 10 Gb ?

RouterOS General
1

Hello,
I’m quite new to Mikrotik but it seems there’s something wrong in my setup.
I have 2 CRS210-8G-2S+ connected with a fiber (SFP+).
When I test bandwith between the 2 I expect something like 10 Gb but here’s what I get :

/tool bandwidth-test duration=15s 192.168.0.250 direction=both
                status: done testing
              duration: 15s
            tx-current: 102.6Mbps
  tx-10-second-average: 92.7Mbps
      tx-total-average: 69.1Mbps
            rx-current: 31.0Mbps
  rx-10-second-average: 36.0Mbps
      rx-total-average: 29.3Mbps
          lost-packets: 0
           random-data: no
             direction: both
               tx-size: 1500
               rx-size: 1500

92 Mbps tx and 36 Mbps Rx are nowhere near 10000 Mbps.
The 10 Gb led is on and there is no other connexion between the 2 CRS.
What may be wrong ?

2

Probably CPU can’t saturate 10Gbps link, however, those results do seem a little low.
What happens if you try 1G copper link instead?
A more realistic result will be obtained by testing with a device connected to each switch.

3

Nothing. Switching is done in hardware. Traffic generation is done in software.
The CPU isn’t very powerful and can’t generate anything like enough traffic to saturate the link, as you have seen. Is this a surprise?
You need to test through the device, not to it or from it.

4

Ok, thanks for the help.
It’s a surprise the CPU cant produce the bandwitdh …
I wanted to start from the beginning.
So, I’ve tried iperf from two physical servers connected each side of the CRSs.

iperf -c 192.168.0.17
------------------------------------------------------------
Client connecting to 192.168.0.17, TCP port 5001
TCP window size: 20.7 KByte (default)
------------------------------------------------------------
[  3] local 192.168.0.63 port 59115 connected with 192.168.0.17 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.06 GBytes    910 Mbits/sec

Much better.
Tried with 6 in parallel from 2 servers and it’s ok too :

[SUM]  0.0-10.0 sec  1.07 GBytes    918 Mbits/sec
[SUM]  0.0-10.0 sec   977 MBytes   819 Mbits/sec

More than 1 Gb so.

5

Remember that its a switch , the CPU is only there to run the OS and such.

all L2 traffic will be handled by the switch chip.

If it was a CCR1036 or 1072 then the cpu would happily generate that kind of traffic