Hi Rita_Wang
We use our own designed motherboard. The verification function of the motherboard hardware on Linux 5.10.52 is good.
CPU version:

Both network ports use RTL821F chips. The old router was bought 20 years ago and can obtain IP normally, but it is somewhat unstable under the TP-LINK brand. The new router was purchased from Huawei in 2023 and can only obtain IPv6 addresses and DNS, but cannot obtain IPv4 IP addresses。