IPsec slow download from server, upload fine

Hi,

I have an RB1100x4, which I am trying to use as a VPN server. I am using IPsec SHA1 AES-256-CBC connecting with Windows 10 clients. The connections are establishing fine and everything is working.

However when downloading via SMB3 from the server I am only achieving around 40-80mpbs of a 250mbps line speed. When uploading a file to the server the full 250mbps is achieved.

I have the following in my firewall rules:


add action=accept chain=forward comment="defconf: accept in ipsec policy" \
    ipsec-policy=in,ipsec
add action=accept chain=forward comment="defconf: accept out ipsec policy" \
    ipsec-policy=out,ipsec

In mangle I have this:

add action=masquerade chain=srcnat comment="defconf: masquerade" ipsec-policy=\
    out,none out-interface="1 Gigaclear WAN"

An iperf report the following way reports the same thing:

[  4] local 10.0.5.249 port 64667 connected to 10.0.100.50 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  6.75 MBytes  56.6 Mbits/sec
[  4]   1.00-2.00   sec  6.00 MBytes  50.3 Mbits/sec
[  4]   2.00-3.00   sec  7.88 MBytes  66.1 Mbits/sec
[  4]   3.00-4.00   sec  8.50 MBytes  71.2 Mbits/sec
[  4]   4.00-5.00   sec  8.12 MBytes  68.2 Mbits/sec
[  4]   5.00-6.00   sec  8.88 MBytes  74.4 Mbits/sec
[  4]   6.00-7.00   sec  9.25 MBytes  77.7 Mbits/sec
[  4]   7.00-8.00   sec  9.88 MBytes  82.8 Mbits/sec
[  4]   8.00-9.00   sec  8.62 MBytes  72.4 Mbits/sec
[  4]   9.00-10.00  sec  7.50 MBytes  62.9 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  81.4 MBytes  68.3 Mbits/sec                  sender
[  4]   0.00-10.00  sec  81.3 MBytes  68.2 Mbits/sec                  receiver

However if I put it into multiple connection mode, I get more like what I would expect:

iperf3 -c 10.0.100.50 -P4
Connecting to host 10.0.100.50, port 5201
[  4] local 10.0.5.249 port 64693 connected to 10.0.100.50 port 5201
[  6] local 10.0.5.249 port 64694 connected to 10.0.100.50 port 5201
[  8] local 10.0.5.249 port 64695 connected to 10.0.100.50 port 5201
[ 10] local 10.0.5.249 port 64696 connected to 10.0.100.50 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  6.25 MBytes  52.4 Mbits/sec
[  6]   0.00-1.00   sec  1.62 MBytes  13.6 Mbits/sec
[  8]   0.00-1.00   sec  5.25 MBytes  44.0 Mbits/sec
[ 10]   0.00-1.00   sec  2.75 MBytes  23.0 Mbits/sec
[SUM]   0.00-1.00   sec  15.9 MBytes   133 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   1.00-2.00   sec  5.00 MBytes  42.0 Mbits/sec
[  6]   1.00-2.00   sec  4.12 MBytes  34.6 Mbits/sec
[  8]   1.00-2.00   sec  7.38 MBytes  61.9 Mbits/sec
[ 10]   1.00-2.00   sec  4.38 MBytes  36.7 Mbits/sec
[SUM]   1.00-2.00   sec  20.9 MBytes   175 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   2.00-3.00   sec  5.62 MBytes  47.2 Mbits/sec
[  6]   2.00-3.00   sec  5.88 MBytes  49.3 Mbits/sec
[  8]   2.00-3.00   sec  6.50 MBytes  54.5 Mbits/sec
[ 10]   2.00-3.00   sec  4.25 MBytes  35.7 Mbits/sec
[SUM]   2.00-3.00   sec  22.2 MBytes   187 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   3.00-4.00   sec  6.00 MBytes  50.3 Mbits/sec
[  6]   3.00-4.00   sec  7.62 MBytes  63.9 Mbits/sec
[  8]   3.00-4.00   sec  5.00 MBytes  41.9 Mbits/sec
[ 10]   3.00-4.00   sec  3.00 MBytes  25.1 Mbits/sec
[SUM]   3.00-4.00   sec  21.6 MBytes   181 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   4.00-5.00   sec  7.62 MBytes  64.0 Mbits/sec
[  6]   4.00-5.00   sec  6.50 MBytes  54.5 Mbits/sec
[  8]   4.00-5.00   sec  6.12 MBytes  51.4 Mbits/sec
[ 10]   4.00-5.00   sec  3.75 MBytes  31.5 Mbits/sec
[SUM]   4.00-5.00   sec  24.0 MBytes   201 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   5.00-6.00   sec  4.00 MBytes  33.6 Mbits/sec
[  6]   5.00-6.00   sec  5.62 MBytes  47.2 Mbits/sec
[  8]   5.00-6.00   sec  4.25 MBytes  35.7 Mbits/sec
[ 10]   5.00-6.00   sec  6.62 MBytes  55.6 Mbits/sec
[SUM]   5.00-6.00   sec  20.5 MBytes   172 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   6.00-7.00   sec  5.25 MBytes  44.0 Mbits/sec
[  6]   6.00-7.00   sec  6.50 MBytes  54.5 Mbits/sec
[  8]   6.00-7.00   sec  2.00 MBytes  16.8 Mbits/sec
[ 10]   6.00-7.00   sec  8.88 MBytes  74.4 Mbits/sec
[SUM]   6.00-7.00   sec  22.6 MBytes   190 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   7.00-8.00   sec  3.50 MBytes  29.3 Mbits/sec
[  6]   7.00-8.00   sec  7.88 MBytes  66.0 Mbits/sec
[  8]   7.00-8.00   sec  6.75 MBytes  56.6 Mbits/sec
[ 10]   7.00-8.00   sec  7.50 MBytes  62.9 Mbits/sec
[SUM]   7.00-8.00   sec  25.6 MBytes   215 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   8.00-9.00   sec  7.38 MBytes  61.9 Mbits/sec
[  6]   8.00-9.00   sec  3.25 MBytes  27.3 Mbits/sec
[  8]   8.00-9.00   sec  6.62 MBytes  55.6 Mbits/sec
[ 10]   8.00-9.00   sec  6.75 MBytes  56.7 Mbits/sec
[SUM]   8.00-9.00   sec  24.0 MBytes   201 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[  4]   9.00-10.00  sec  6.25 MBytes  52.4 Mbits/sec
[  6]   9.00-10.00  sec  4.50 MBytes  37.7 Mbits/sec
[  8]   9.00-10.00  sec  7.75 MBytes  65.0 Mbits/sec
[ 10]   9.00-10.00  sec  6.62 MBytes  55.6 Mbits/sec
[SUM]   9.00-10.00  sec  25.1 MBytes   211 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  56.9 MBytes  47.7 Mbits/sec                  sender
[  4]   0.00-10.00  sec  56.6 MBytes  47.5 Mbits/sec                  receiver
[  6]   0.00-10.00  sec  53.5 MBytes  44.9 Mbits/sec                  sender
[  6]   0.00-10.00  sec  53.4 MBytes  44.8 Mbits/sec                  receiver
[  8]   0.00-10.00  sec  57.6 MBytes  48.3 Mbits/sec                  sender
[  8]   0.00-10.00  sec  57.5 MBytes  48.2 Mbits/sec                  receiver
[ 10]   0.00-10.00  sec  54.5 MBytes  45.7 Mbits/sec                  sender
[ 10]   0.00-10.00  sec  54.4 MBytes  45.6 Mbits/sec                  receiver
[SUM]   0.00-10.00  sec   222 MBytes   187 Mbits/sec                  sender
[SUM]   0.00-10.00  sec   222 MBytes   186 Mbits/sec                  receiver

iperf Done.

If anyone could provide any suggestions or troubleshooting steps i would be most appreciative

Thank you in advance

https://forum.mikrotik.com/viewtopic.php?f=3&t=140313