When running the Cloudflare Zero Trust tunnel connector in a Docker container, with Docker running on a Proxmox LXC, I got the following error in the log:
Failed to sufficiently increase send buffer size (was: 208 kiB, wanted: 2048 kiB, got: 416 kiB). See https://github.com/quic-go/quic-go/wiki/UDP-Buffer-Sizes for details.To correct this, I did:
On the Proxmox node shell (pve in my case), and not on the LXC running Docker:
nano /etc/sysctl.d/tcpbuffer.confPaste in:
# Increase TCP buffer limits
net.ipv4.tcp_wmem = 4096 65536 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.optmem_max = 65536Save and exit.
run “service procps force-reload” in the shell, and restart the Docker Container. Check the log to see that the error message does not appear.
This also seems to fix the need to set “Disable Chunked Encoding” for some hosts in the tunnel configuration (e.g. error 501 on proxmox-console).
Information on Cloudflare Zero Trust:
