[SOLVED] Weird behavior with container network traffic

[LmanTW]

Hello to the Proxmox community, I just downgraded back to PVE 8 (reinstall) because some features I was previously using are broken.

My server is running on a USB WiFi dongle, my setup was working perfectly fine in my previous PVE 8 installation. But now I'm experiencing some weird behaviors where when there's network traffic in the container, some packet will get interrupt inside and outside the container. I'm pretty sure this is is not a Proxmox issue but I don't really know where else to ask.

I run a ping google.com in the host, and then run some command in the container that involke network traffic. I can see a lot of `DUP` in the ping. Connecting to the Minecraft server I'll experience latency spikes (although this behavior only appear sometimes, at other times after the network service restart or reboot, it seems to disappear).

The network configuration is basically the same as I had before, so I'm very confused about why it's happening now.

This is my /etc/network/interfaces:

auto lo
iface lo inet loopback

# Ethernet, but with no internet.
auto enp2s0
iface enp2s0 inet static
        address 192.168.2.2/24

# The wifi dongle.
auto wlx30169de6dc34
iface wlx30169de6dc34 inet static
        address 192.168.1.2/24
        gateway 192.168.1.1
        wpa-ssid ...
        wpa-psk ...

auto vmbr-wireless
iface vmbr-wireless inet static
        address 192.168.10.0/24
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up iptables -t nat -A POSTROUTING -s "192.168.10.0/24" -o wlx30169de6dc34 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s "192.168.10.0/24" -o wlx30169de6dc34 -j MASQUERADE

        # Allow forwarding between interfaces.
        post-up iptables -A FORWARD -i wlx30169de6dc34 -o vmbr-wireless -j ACCEPT
        post-up iptables -A FORWARD -i vmbr-wireless -o wlx30169de6dc34 -j ACCEPT
        post-down iptables -D FORWARD -i wlx30169de6dc34 -o vmbr-wireless -j ACCEPT
        post-down iptables -D FORWARD -i vmbr-wireless -o wlx30169de6dc34 -j ACCEPT

        # Minecraft Java server port forwarding.
        post-up iptables -t nat -A PREROUTING -i wlx30169de6dc34 -p tcp --dport 25565 -j DNAT --to-destination 192.168.10.104:25565
        post-up iptables -A FORWARD -p tcp -d 192.168.10.104 --dport 25565 -j ACCEPT
        post-down iptables -t nat -D PREROUTING -i wlx30169de6dc34 -p tcp --dport 25565 -j DNAT --to-destination 192.168.10.104:25565
        post-down iptables -D FORWARD -p tcp -d 192.168.10.104 --dport 25565 -j ACCEPT

        # Minecraft Bedrock server port forwarding.
        post-up iptables -t nat -A PREROUTING -i wlx30169de6dc34 -p udp --dport 19132 -j DNAT --to-destination 192.168.10.104:19132
        post-up iptables -A FORWARD -p udp -d 192.168.10.104 --dport 19132 -j ACCEPT
        post-down iptables -t nat -D PREROUTING -i wlx30169de6dc34 -p udp --dport 19132 -j DNAT --to-destination 192.168.10.104:19132
        post-down iptables -D FORWARD -p udp -d 192.168.10.104 --dport 19132 -j ACCEPT

source /etc/network/interfaces.d/*

I do acknowledge that a `.0` ending address is weird, but since it works fine before I'm going to assume this is not the issue. The WiFi dongle is using the RTL88x2BU driver, same as what I was using previously. I also tested with the Minecraft port forwarding parts removed, but the weird behavior still persist.

 

[LmanTW]

I switched to a 5G connection, and I think it works fine now. For some reason...