Hello and greeting from Red Cross Germany!
We have around 7 locations and all of them are connected with OpnSense Gateway VPNs.
The problem we are facing is we use Zyxel and Fritzbox routers and Telekom Reigo Internet connections.
Our users work with RDP and connect to a location but every time they face a 5-10 seconds loss of connection every 5 minutes. The Ping works 100% and there is no error. Screenshot below.
Any idea how can we Diagnose this or fix it?
(https://i.ibb.co/C02BzFC/Microsoft-Teams-image-35.png)
Could you pls clarify a few things:
- What do you mean by "OpnSense Gateway VPNs"? Which VPN technology is used? IPSec? OpenVPN? Can you share some configuration details/screenshots?
- Under which exact circumstances does the problem occur? User from location A tries to connect via RDP (through the VPN) to a machine at location B? Does it happen between all locations, or is it maybe limited to only one or two?
- Can you please share a topology plan including the Zyxel/Fritzbox devices to clarify the following:
- Are your OPNsense gateways the only device behind the "Plasterouter"s, or is there a mish-mash setup?
- Are only certain ports opened from Zyxel/Fritzbox to OPNsense or are you using an "exposed host" type configuration?
- Do you have static IPs on each site, or are some dynamic addresses involved?
- Dual-stack or IPv4 only?
Just a FYI, there is board dedicate to VPN issues. You might have better luck over there. https://forum.opnsense.org/index.php?board=36.0
For testing set Interfaces : LAN : MSS to 1300. If this doesn't help, block UDP/3389, sometimes the UDP implementation of RDP is slower than it should be. There were also some fixes from Microsoft regarding this.