Slow LAN bandwidth

RouterOS General
1

Hi all!

Sorry for my bad English.
I have a RB951G-2HnD router and a CRS226-24G-2S+RM cloud router switch.
I’m using the latest stable firmware (6.36) on this devices.
The router has a factory default configuration.
The cloud router switch has a factory default configuration also but I set “automatic IP acquisition” instead of the static 192.168.88.1.
I connected the RB951G-2HnD second port (LAN) with the CRS226 first port via a 10 meter length CAT5E factory made cable.
The CRS226 obtained the 192.168.88.253 IP address from the RB951G-2HnD.
I connected to the CRS226 second port my PC via a 2 meter length CAT5E factory made cable.
My PC obtained the 192.168.88.254 IP address from the RB951G-2HnD.

I think the measured TCP throughput is very slow in this typically basic configuration.

In the router (to the switch):
Tx: 54MBit/sec
Rx: 34MBit/sec

In the switch (to the router):
Tx: 31MBit/sec
Rx: 53MBit/sec

This values was the “Rx/Tx total average” -s.

I tried the measure in command line also, but no changes in the values. In the RB951G-2HnD to the CRS226:
##################################################
[admin@MikroTik] /tool> bandwidth-test 192.168.88.253 user=admin direction=transmit protocol=tcp duration=10s
status: done testing
duration: 10s
tx-current: 47.0Mbps
tx-10-second-average: 54.9Mbps
tx-total-average: 54.9Mbps
random-data: no
direction: transmit

[admin@MikroTik] /tool>
##################################################

This values with UDP protocol was ten times faster: 540…560MBit/sec

Is this values is normal? I think not.
I think the normal throughput should near 1000MBit/sec. What do you recommend? What can I check? What is wrong? Or this is normal?

update: I tried the connection between the devices with an 1 meter length factory made CAT 6 cable too - but no changes in the measured values :frowning:

update2:
I installed to my Windows PC the Mikrotik Bandwidth Test 0.1 software.
My PC has a 1000MBit/sec network card.
The PC is connected to the CRS226 second port.

The bandwidth values to the RB951G-2HnD (across the CRS226):
Rx: 91,4MBps
Tx: 97,6MBps

The bandwidth values to the CRS226:
Rx: 11,7MBps
Tx: 33,9MBps

I don’t understand…
How can this values so slow from my PC to the CRS226? And from my PC to the router (across the CRS226!!!) how can 100MBit up/down?
All devices has only gigabit ethernet ports… very mystic…

Has anybody any idea or suggestion?

2

Check that on both sides of the ethernet link the layer2 is set to “auto”.
Don’t use fixed settings like 100 Mbit or FULL duplex. It will ruin your day.

3

Thanks your fast answer. Where can I find the layer2 settings? I did’n find anywhere :frowning:

If I choose the RB951’s ether2 interface I see this (general tab):
name: ether2-master
type: Ethernet (fix)
MTU: 1500
L2 MTU: 1598
Max L2 MTU: 4074 (fix)
MAC: mac add… (fix)
ARP: Enabled
Master port: none
Bandwidth Tx/Rx: none/none
Switch: switch1

The “fix” values I can’t modify.
Maybe the MTU / L2 MTU is not so good? This was the default values…

On the “ethernet” tab:
auto-negotiation is checked
Tx/Rx flow control: off/off
All advertised are checked.
This was the defaults also here.

4

A stupid question:
In the CRS226 “Quick set” I can choose the mode: “Router” or “Bridge”.
In this case (this was the default) the mode is “Router”. Maybe can I change to the “Bridge”? I want to use the CRS226 as a normal switch.
Or this is unaffected for my slow bandwidth problem?