Dropped network packets affecting applications

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Environment

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

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.