RB850Gx2 very low speed

Hardware MikroTik hardware general
1

There is a problem
In this scheme I can not get the speed of copying a file from a server to computer more than 150Mbit/s.
Router CPU load 5-15%
If connect directly - 850mbit/s
Configurations very simple- no queues, no firewall rules, no connection tracking etc. No errors, all interfaces of 1Gb/s.

[admin@MikroTik] > /export
# oct/22/2015 18:45:28 by RouterOS 6.32.3
# software id = XXXXXXX
#
/interface ethernet
set [ find default-name=ether1 ] mac-address=4C:5E:0C:72:5C:1D
set [ find default-name=ether2 ] mac-address=4C:5E:0C:72:5C:1E
set [ find default-name=ether3 ] mac-address=4C:5E:0C:72:5C:1F master-port=ether2
set [ find default-name=ether4 ] mac-address=4C:5E:0C:72:5C:20 master-port=ether2
set [ find default-name=ether5 ] mac-address=4C:5E:0C:72:5C:21 master-port=ether2
/ip pool
add name=pool-88 ranges=192.168.88.10-192.168.88.100
/ip dhcp-server
add address-pool=pool-88 disabled=no interface=ether2 name=server1
/ip firewall connection tracking
set enabled=no
/ip address
add address=192.168.88.254/24 interface=ether2 network=192.168.88.0
/ip dhcp-client
add dhcp-options=hostname,clientid disabled=no interface=ether1
/ip dhcp-server network
add address=192.168.88.0/24 dns-server=192.168.80.254 gateway=192.168.88.254 ntp-server=192.168.80.254
/ip dns
set servers=192.168.80.254
/system routerboard settings
set cpu-frequency=533MHz protected-routerboot=disabled
[admin@MikroTik] >
2

In the program Wireshark I see a lot of messages “TCP out-of-order” and “TCP Dup ACK”

3

Tweak MTU to make MSS happy.

4

MTU on interfaces set by default 1500B (in the first message is a complete router configuration)
I tried to set 1400, then 1560 on Ether1&2. Nothing has changed.

Then I tried the following commands:
/ip firewall connection tracking set enabled=auto
/ ip firewall mangle
add action = change-mss chain = forward log = yes new-mss = 1360 protocol = tcp tcp-flags = syn
Nothing

Why are there to change MTU and what value should be set?

5

I have simplified the configuration.
Now it’s just a bridge
Server is connected to the interface Ether2.
computer to the Ether3.

Speed up to 100 Mbit/s :frowning:

[admin@MikroTik] > /export
# oct/22/2015 21:51:02 by RouterOS 6.32.3
# software id = xxxxxxx
#
/interface bridge
add name=bridge1
/interface ethernet
set [ find default-name=ether1 ] mac-address=4C:5E:0C:72:5C:1D
set [ find default-name=ether2 ] mac-address=4C:5E:0C:72:5C:1E
set [ find default-name=ether3 ] mac-address=4C:5E:0C:72:5C:1F
set [ find default-name=ether4 ] mac-address=4C:5E:0C:72:5C:20
set [ find default-name=ether5 ] mac-address=4C:5E:0C:72:5C:21
/interface bridge port
add bridge=bridge1 interface=ether2
add bridge=bridge1 interface=ether3
add bridge=bridge1 interface=ether4
add bridge=bridge1 interface=ether5
/ip dhcp-client
add dhcp-options=hostname,clientid disabled=no interface=bridge1
[admin@MikroTik] >
6

Mikrotik, please repair the routers RB850Gx2 :confused: