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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter13 Configuring LRE
Understanding LRE Features
Beginning with the first profile in a sequence, the switch attempts to apply each profile within that
sequence to the LRE interface. The switch continues these attempts until it converges (convergence time
refers to the time required for the switch to settle on an appropriate profile for the LRE interface). The
link is DOWN until a link is established by one of the profiles in the sequence, after which, it is UP.
For additional information on rate selection, see the “Using Rate Selection to Automatically Assign
Profiles” section on page 13-14.
CPE Ethernet Links
The CPE Ethernet link settings define the connection between the CPE Ethernet port and a remote
Ethernet device, such as a PC.
Note From CMS and the CLI, you can configure and monitor the Ethernet link on a Cisco 575 LRE CPE and
the Cisco 585LRE CPE. You can configure and monitor the Ethernet link on a Cisco 576 LRE 997 CPE
only from the CLI. For information about the switch LEDs, refer to the Catalyst 2950 Desktop Switch
Hardware In stallatio n Guide.
Keep these considerations in mind when you have CPE devices connected to the L RE po rts:
•Use the shutdown interface configuration command to disable the LRE interface transmitter on any
LRE ports. This prevents access to the LRE port and prevents the po w er emitted from the port from
affecting other ports.
•You cannot configure the flow-control setting on the LRE ports. The flow-control setting on the CPE
Ethernet port is automatically disabled in half-duplex mode and is automatically enabled in
full-duplex mode.
Table13-4 LRE Rate Selection Sequencesfor the Catalyst 2950ST-24 LRE 997 Switches
LRE-SEQ-
COMPLETE-REACH LRE-SEQ-
DOWNSTREAM LRE-SEQ-SYM LRE-SEQ-SYM-
LONGREACH LRE-SEQ-
UPSTREAM LRE-SEQ-
VIDEO-TRANSMIT1
LRE-12-9 LRE-12-9 LRE-9 LRE-6-4 LRE-12-9 LRE-12-9
LRE-12-3 LRE-12-3 LRE-6 LRE-4 LRE-9 LRE-9
LRE-9 LRE-9 LRE-4 LRE-9-3 LRE-9-6 LRE-9-6
LRE-9-6 LRE-9-6 LRE-6-3 LRE-6 LRE-9-4
LRE-9-4 LRE-9-4 LRE-4-3 LRE-9-4 LRE-9-3
LRE-6 LRE-9-3 LRE-6-4
LRE-6-4 LRE-6 LRE-4
LRE-9-3 LRE-6-4 LRE-12-3
LRE-4 LRE-6-3 LRE-9-3
LRE-6-3 LRE-4 LRE-6-3
LRE-4-3 LRE-4-3 LRE-4-3