I have proxmox connected to OpenWrt installed on a real machine. It worked with the previous router, but when I switched to the OpenWrt router, the proxmox VM could not get an IP address. When I took a tcpdump on OpenWrt, OpenWrt sent a DHCP offer to the proxmox side, but the offer communication failed. The DHCP server is kea. The proxmox host can connect to the Internet if you specify a fixed IP.