Slow Transfer speed- Auto Site to Site VPN

[Tiasan21]

We have an issue transferring files from Auto-VPN Site to Site with two VMs from different sites.

Site 1- US - 1GB Circuit

Site 2- Germany  - 500 mb Circuit 

• Transfer speed between two sites through the LAN (VM to VM) is 700k per sec   
• MX firewall speed running same speed as ISP provider. 

SMB & MTU & Iperf

>>>>>>>>>>>>>>>
 Iperf Test
- Iperf between MX's Meraki - Normal seep ;;; 200-500mbs

- Iperf between VM to VM from US & Germany ;;; 700KB/s - 3MB/s
SMB Protocol 

- Tested Iperf with SMB2 - no change

- Tested Iperf with SFTP - no change 

MTU
- No miss match MTU

- Change MTU - no change 

Bring the Site to Site VPN down / up - no change.

Wireshark not showing enough date to identify the root cause.

Thank you, 

[RWelch]

What MX firmware versions are you running? 

Slow Site-to-Site VPN traffic 

[Tiasan21]

MX95 Version MX 19.1.6

[RWelch]

You might consider trying New MX 19.1.7.1 other release: fixes issue with many clients to see if it improves your throughput.  I noticed an improvement on several MX75, MX95s and MX105s after upgrading to MX19.1.7.1.

BUG FIXES - LIMITED PLATFORM FIXES

• Fixed an MX 19.1.7 regression that could result in MX75, MX85, MX95, MX105, MX250, and MX450 appliances servicing many clients to experience intermittent periods of heightened packet drops and latency. This resolves known issue MX-36338.

[RaphaelL]

Have you tried disabling IPS ?

Can you perform a packet capture ? Do you see fragmentation ? Retransmissions ?