Hi all! What is the cheapest avaiable managed and unmanaged switch with 2.5 GbE ports or uplinks?

I created a certificate with OpenSSL and uploaded that to the router as PKCS#12 then the name of the certification is reserved (I can't upload again with the same name), but not seen in the list (reboot not help). I wanted to use 3072 BIT RSA key, be...