Chapter 13
Replacing Hardware Components
Field-Replaceable Units (FRUs)
This chapter explains how to replace hardware components on the router. It discusses
the following topics:
Field-replaceable units (FRUs) are router components that can be replaced at the
customer site. Replacing most FRUs requires minimal router downtime. The router
uses the following types of FRUs:
Hot-removable and hot-insertable FRUs-You can remove and replace these
components without powering off the router or disrupting the routing functions.
Hot-pluggable FRUs-You can remove and replace these components without
powering off the router, but the routing functions of the system are interrupted
when the component is removed.
Table 23 on page 88 lists the FRUs for the MX240 router. Before you replace an SCB
or a Routing Engine, you must take the host subsystem offline (see "Taking the Host
Subsystem Offline" on page 96).
Field-Replaceable Units (FRUs)
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