Dropped network packets affecting applications

  • Document ID:7006074
  • Creation Date:21-May-2010
  • Modified Date:08-Nov-2012
    • Micro Focus Products:
      Open Enterprise Server
    • SUSE Products:
      SUSE Linux Enterprise Desktop
      SUSE Linux Enterprise Server

Environment

Novell Open Enterprise Server 2 (OES 2) Linux
SUSE Linux Enterprise Server 11
SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Desktop 11
SUSE Linux Enterprise Desktop 10

Situation

High packet loss has been observed to cause:
  • UDP-based communications are unstable or have erratic behavior
  • OCFS2 Cluster instability, erratic behavior and cluster failure
  • LinuxHA Cluster instability, erratic behavior and cluster failure
  • NFS slowness, unreliability or failure
  • Xen DomU based applications may be slow
  • Periods of random TCP slowness
The ifconfig and netstat -i commands shows a significant number of dropped packets, collisions or errors.

Resolution

Some causes for dropped packets, collisions or errors include:
  • Network driver issues
  • Limited network bandwidth
  • Router problems
  • Load balancing failure
  • Over extended server resources
  • LAN card configuration
Some possible resolutions:

Network driver issue
  • Consider running rpm -V  on the kernel RPM package to ensure the drivers are not damaged. If they are, consider reinstalling the kernel RPM package.
  • Update to the current available kernel package with the newest network drivers.
Limited network bandwidth
  • Add dedicated private networks
  • Re-evaluate your router configuration
Over extended server resources
  • Check for sufficient memory and disk space
  • Consider distributing application work loads to additional servers