Why does Red Hat Enterprise Linux not respond to SYN requests intermittently?

Solution Verified - Updated -


  • Why does Red Hat Enterprise Linux intermittently not respond to SYN requests?
  • Server does not answer some specific SYN Packets
  • Webserver does not respond for sessions (SYN requests) sometimes
  • SYN Packets being ignored occasionally by RHEL Apache server
  • LDAP server occasionally dropping SYNs
  • Any server, regardless of the application layer, may occasionally silently drop TCP packets with SYN flag set
  • The Load Balancer which is between client and Red Hat servers is not getting response of SYN packets, the SYN-ACK from the RHEL server goes missing
  • SYN sent through F5 is silently dropped by client
  • What steps need to be taken when clients using TCP Timestamps are hidden behind a NAT?
  • Is it safe to enable net.ipv4.tcp_tw_recycle and/or net.ipv4.tcp_tw_reuse sysctl options in a NAT environment?


  • Red Hat Enterprise Linux
  • Network traffic using Transmission Control Protocol (TCP)
  • Network with load balancer (such as BigIP F5) or a router which performs Network Address Translation (NAT)

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Current Customers and Partners

Log in for full access

Log In

New to Red Hat?

Learn more about Red Hat subscriptions

Using a Red Hat product through a public cloud?

How to access this content