Specifications

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Cisco ME 3800X and ME 3600X Switch Command Reference

OL-23401-02

Chapter 2 Cisco ME 3800X and ME 3600X Switch Cisco IOS Commands

ql-enabled rep-segment

To configure a Synchronous Ethernet (SyncE) Resilient Ethernet Protocol (REP) workaround for

network resiliency and to avoid timing loops when there are any network failures within the REP

segment, use the ql-enabled rep-segment command in global configuration mode. To disable the

workaround, use the no form of this command.

ql-enabled rep-segment segment-id

no ql-enabled rep-segment

Syntax Description

Command Modes Global configuration

Command History

Usage Guidelines Some SyncE networks use Ethernet Synchronous Messaging Channel (ESMC) with source-specific

multicast (SSM) to ensure that the highest quality level clock available is selected and to prevent timing

loops in the network. Because ESMC SSM is not supported on the switch, we recommend configuring

the SyncE network as a REP segment to provide a REP workaround.

If you do not configure a REP workaround, an intermittent failure or change in network topology can

cause timing loops in the SyncE network. Configuring REP allows the segment to automatically respond

to a failure in the ring and avoid timing loops by changing the direction of the reference clock path.

SyncE uses REP only for failure detection, and not for timing topology discovery or timing loop

prevention. Timing loops can still occur if port priority is not correctly configured.

You can see if a REP segment is enabled by entering the show network-clocks privileged EXEC

command.

See the software configuration guide for more information about configuring REP segments and

configuring the REP workaround.

Examples This example shows how to configure the REP segment 3 as the quality-level workrooms.

Switch(config)# dl-enabled segment 3

Related Commands

segment-id Specifies the SyncE REP segment to be used for the ESMC SSM workaround. The

segment ID range is 1 to 1024.

Release Modification

12.2(52)EY This command was introduced.

Command Description

network-clock-select Configures the network clock for the switch.

show network-clocks Displays SyncE configuration on the switch.