IP fragmentation fails and fragmented packets get dropped

Solution Verified - Updated -

Issue

  • We have a three node Oracle RAC and this morning we had problem with one node. When we reviewed the historic netstat -s ouput we noticed that the following counter spiked around that time.
 54672220 packet reassembles failed
  • After that event the module could not be pinged with a packet size greater than the MTU.
# ping <IP Addr> -s 1600

Environment

  • Red Hat Enterprise Linux 6.6 (kernel-2.6.32-504.el6) and later
  • Red Hat Enterprise Linux 6.7.z (kernel-2.6.32-573.7.1.el6) and earlier
  • Oracle RAC or other application which commonly sends IP fragments
  • IP fragmentation
  • Systems with many CPU cores
    • In one instance, the system had 160 CPU cores
  • Sytemss with smaller amounts of CPUs are not affected.
    • For example, we could not reproduce this on a machine with 12 CPU cores

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase of over 48,000 articles and solutions.

Current Customers and Partners

Log in for full access

Log In
Close

Welcome! Check out the Getting Started with Red Hat page for quick tours and guides for common tasks.