Alcatel Carrier Internetworking Solutions 6648 - Manual (Page 296)

Troubleshooting a Complete Failure Troubleshooting Server Load Balancing
page 17-4 OmniSwitch Troubleshooting Guide September 2005
Troubleshooting a Complete Failure
Gathering pertinent information is essential in order to properly characterize the problem. Obtain symp-
tom facts, review all recent network or architecture changes, localize the problem, e.g. does it affect only
certain floors, or departments? Devise an action plan.
The first step in any troubleshooting process is to gather information. The more information you have
about the symptoms and characteristics of a problem, including when it first occurred, the better your
chances of solving the problem quickly and efficiently. Typical questions you might ask at this stage
before beginning to troubleshoot spanning tree include:
• Do the symptoms occur regularly or intermittently?
• Are the symptoms related to certain applications (running simultaneously with), or do they affect all
network operations?
• Are other SLB clusters located on this switch malfunctioning?
• How many users are involved?
• Do the symptoms correlate to other activities in the network?
• When was the first occurrence of the symptom?
• Were there any changes in any hardware or software network components?
• Has anyone connected or disconnected a PC (laptop or desktop), or another component to or from the
network?
• Has anyone installed an interface card in a computer/server?
• Has DHCP possibly provided a lease to a user with the SLB VIP?
• Has anyone stepped on a cable?
• Has any maintenance work been performed in the building recently (by a telephone company or build-
ing maintenance personnel, for example)?
• Has anyone (including cleaning personnel) moved/unplugged any equipment or furniture?
Note. In general, it is advised to restart a device immediately after major changes have been made to it;
you want to make sure that all your changes have been saved. You also want to verify that after a reboot
(equivalent to a power outage or a crash), the device will come up with the correct and complete configu-
ration.