Host Subsystem In An Ex9253 Switch - Juniper EX9253 Hardware Manual

To install a line card in an EX9253 switch, follow instructions in
Switch" on page 143. To remove a line card from an EX9253 switch, follow instructions in
Line Card from an EX9253 Switch" on page
To install a transceiver in an EX9253 switch, follow instructions in
QSFP28 Transceiver
. To remove a transceiver from an EX9253 switch, follow instructions in
Transceiver Remove a QSFP28 Transceiver
or

Host Subsystem in an EX9253 Switch

The host subsystem provides switching protocol processes as well as software processes that control
the switch' s interface, the chassis components, system management, and user access to the switch.
These switching processes run on top of a kernel that interacts with the Packet Forwarding Engine. The
host subsystem consists of two Routing Engines (REs). The RE is an integrated board that provides
Routing Engine and Control Board functionality and supports virtualization. If two REs are installed, one
functions as the primary and the other functions as the backup. If the primary host subsystem (or either
of its components) fails, the backup can take over as the primary.
The RE is a hot-removable and hot-insertable field-replaceable unit (FRU). You can remove and replace it
while the switch is running without turning off power to the switch or disrupting switching functions. At
least one RE must be installed in the switch. To ensure proper operation of the switch, you must install a
replacement RE shortly after removing an RE from the chassis. The REs are installed in the slots labeled
RE0 and RE1 on the front panel of the chassis.
Figure 6 on page 15 shows the components on the faceplate of an RE.
Figure 6: Components on the Faceplate of an RE
1 USB port
—
"Installing a Line Card in an EX9253
140.
Install a Transceiver
.
8 Time of day port with LEDs (ToD) (This port
—
is reserved for future use)
"Removing a
Install a
or
Remove a
15