title: Performance tuning via sysctl, what is the difference between setting net.core.rmem_default (r/w) / net.ipv4.tcp_mem / net.ipv4.udp_mem
body: <p>What is the difference between setting read/write mem default via net/core and setting the protocol min/max/default net/ipv4 in sysctl?</p>
  
  <p>Detailed explanation or resource request </p>
  
  <blockquote>
    <p>net.core.wmem_default <br>
    net.core.rmem_default <br>
    net.ipv4.tcp_mem <br>
    net.ipv4.udp_mem <br></p>
  </blockquote>
  
  <p>Thanks</p>