Dear MikroTik Community,
I’d like to bring attention to a potential bug I’ve encountered with RouterOS, specifically related to Wireguard performance over IPv6. I believe this issue may be of interest to other users and the MikroTik development team.
Context:
I’ve been attempting to establish a Wireguard tunnel between a MikroTik router (hAP ax²) and a remote server. Due to high latency with IPv4 routes between my local ISP and the server, I initially opted to set up the tunnel over IPv6.
Issue Description:
When connecting the Wireguard tunnel through the MikroTik router over IPv6, I experienced extremely slow data transfer rates of approximately 100 Kbps. This is in stark contrast to the expected performance, as iperf3 tests between my local network and the server showed a maximum UDP throughput of around 250 Mbps.
Troubleshooting Steps:
- Double-checked the Wireguard configuration
- Benchmarked the server
- Monitored CPU usage
- Adjusted MTU values
- Upgraded RouterOS versions (tested on 7.15, 7.15.3, and 7.16rc4)
Resolution:
After an extensive day of troubleshooting, I switched the tunnel to use IPv4 instead of IPv6. This change resulted in data transfer speeds of approximately 200 Mbps, which is consistent with Wireguard tunnels established to the same server via a regular PC client and aligns with the available bandwidth between the local network and the server.
Has anyone else experienced similar issues with Wireguard performance over IPv6 on RouterOS? If this is indeed a bug, I believe it should be addressed promptly.
Best regards.