Router on a stick with no bridge interface

RouterOS Beginner Basics
1

I have configured a router on a stick via the SFP port. It seems to work but I haven’t configured any bridge interfaces and everything I’ve researched shows using bridge interfaces. Have I configured this incorrectly? Is there a performance issue with configuring it the way I have. I feed this board with a Mimosa B5 and it’s wireless-to-wireless throughput shows 800mbits but Mikrotik speed tests show 200mbits/udp and 40mbits/tcp.

[admin@*****] /> /interface bridge export
# sep/27/2022 16:12:47 by RouterOS 6.48.4
# software id = Q69N-8A5P
#
# model = CRS109-8G-1S-2HnD
# serial number = *****
/interface bridge add name=loopback

[admin@*****] /> /interface vlan export
# sep/27/2022 16:12:54 by RouterOS 6.48.4
# software id = Q69N-8A5P
#
# model = CRS109-8G-1S-2HnD
# serial number = *****
/interface vlan
add interface=sfp1 name=***** vlan-id=20
add interface=sfp1 name=***** vlan-id=1
add interface=sfp1 name=***** vlan-id=156
add interface=sfp1 name=***** vlan-id=15
add interface=sfp1 name=***** vlan-id=172
add interface=sfp1 name=***** vlan-id=116
add interface=sfp1 name=***** vlan-id=132
add interface=sfp1 name=***** vlan-id=123
[admin@*****] />
2

First off the crs series - especially the 1xx and 2xx versions are primarily switches. You won’t get great routing performance off of these devices.

Second, running a speed test on a device itself is not the correct way to test as the device will use a lot of the CPU to just run the bandwidth test itself. You should have workstation devices connected to the routers to run the bandwidth tests to get accurate info.

Third, since this is a router on a stick and if you only need the one interface to handle traffic, then a bridge is not needed. It is only there to handle traffic across multiple interfaces that need to be on common networks.

3

Thank you for your response, that makes clear the necessity for the bridge interface.

Can you elaborate on your first point. I assume when I’ve reached the routing capacity of the 2xx I will see max CPU usage? I am seeing plenty of CPU overhead available so would you expect I do not need to consider this as the bottleneck?

/system resource monitor
     cpu-used: 23%
  free-memory: 93228KiB

Regarding your second point, I have performed lots of tests using iperf with systems with the same poor results.

4

Yes. Best way of observing CPU load is to run CPU profiler from terminal window (preferably connect using ssh, running winbox can cause some notable load on MT device) … /tool profile. While running profiler, run iperf and observe what kind of load you see.
Another thing to observe is interface utilization (/interface ethernet print stats) in regular intervals to see if some other traffic loads the “stick” interface which may limit the WAN throughput.