It is important to have contingencies in place to counter physical layer
problems.
The presence of
an Uninterruptible Power Supply (UPS), surge protectors, or line filters can
protect a network from short term power interruptions, brownouts, and power
spikes.
It is a good idea to install modular hardware wherever possible.
In that way the failure of a single module will not result in the entire device
being taken off line. Having replacement modules in store is also cost
effective. In the event of component failure, the modules can be
interchangeably used in a variety of compliant chassis.
When changes
are made to device or network configurations, back-up copies of the previous
functional configurations should be on hand in the event of network failure
resulting from these changes.
Having additional cabling and testers on hand is also highly recommended. In
the event of damage to patch cables or damage to backbone cabling it is
essential that replacement cable be on hand to shorten outage duration.
