# SyncE

The `nv unset` commands remove the configuration you set with the equivalent `nv set` commands. This guide only describes an `nv unset` command if it differs from the `nv set` command.

## nv set interface <interface-id> synce bundle-id

Configures the SyncE bundle that this interface belongs to. You can specify a value between 0 and 256. A value of zero indicates no bundle.

### Command Syntax

Syntax | Description
--- | ---
`<interface-id>` | The interface on which you want to configure SyncE.

### Version History

Introduced in Cumulus Linux 5.7.0

### Example

    cumulus@switch:~$ nv set interface swp1 synce bundle-id 0

## nv set interface <interface-id> synce state

Enables and enables SynCe on the specified interface. The default setting is `disabled`.

SyncE is a standard for transmitting clock signals over the Ethernet physical layer to synchronize clocks across the network by propagating frequency using the transmission rate of symbols in the network. A dedicated Ethernet channel, (ESMC), manages this synchronization.

In Cumulus Linux 5.14 and earlier, you specify `enable on` or `enable off` instead of `state enabled` or `state disabled`.

### Command Syntax

Syntax | Description
--- | ---
`<interface-id>` | The interface on which you want to configure SyncE.

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set interface swp1 synce state enabled

## nv set interface <interface-id> synce provider-priority

Configures the frequency source priority for the interface. The clock selection algorithm uses the frequency source priority to choose between two sources that have the same QL. You can specify a value between 1 (the highest priority) and 254 (the lowest priority). The default value is 100.

### Command Syntax

Syntax | Description
--- | ---
`<interface-id>` | The interface on which you want to configure the frequency source priority.

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set interface swp1 synce provider-priority 10

## nv set system synce state

Enables and disables the SyncE service. The default setting is `disabled`.

The SyncE service (`synced.service`) manages:

- Transmitting and receiving SSMs on all SyncE enabled ports using the ESMC.
- The synchronization hierarchy and runs the master selection algorithm to choose the best reference clock from the QL in the SSM.
- Using to the next best clock when the master clock fails. The selection algorithm only selects the best source, which is the Primary Clock source.
- The switchover time if the algorithm also selects a secondary reference clock in case of primary failure.

In Cumulus Linux 5.14 and earlier, you specify `enable on` or `enable off` instead of `state enabled` or `state disabled`.

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set system synce state enabled

## nv set system synce log-level

Configures the logging level that the SyncE service uses. You can set the following values:

- `critical` level logs critical errors and notices.
- `debug` logs fine-grained informational events that are most useful to debug an application.
- `error` logs errors.
- `info` logs informational messages.
- `notice` logs notices.

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set system synce log-level debug

## nv set system synce min-acceptable-ql

Configures SyncE to not track a source with a quality level lower than a specific value. The quality level can be: `eec1`, `eeec`, `ssu-b`, `ssu-a`, `prc`, `eprc`, `prtc`, or `eprtc`, where `eec1` is the lowest quality level and `eprtc` is the highest quality level.

### Version History

Introduced in Cumulus Linux 5.10.0

### Example

    cumulus@switch:~$ nv set system synce min-acceptable-ql ssu-b

## nv set system synce provider-default-priority

Configures the priority for the clock source. You can set a value between 1 and 256. The lowest priority is 1 and the highest priority is 256. If two clock sources has the same priority, the switch uses the lowest clock source.

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set system synce provider-default-priority 256

## nv set system synce wait-to-restore-time

Configures the number of seconds SyncE waits for each port to be up before opening the ESMC for messages. You can set a value between 0 and 720 seconds (12 minutes). The default value is 300 seconds (5 minutes).

### Version History

Introduced in Cumulus Linux 5.5.0

### Example

    cumulus@switch:~$ nv set system synce wait-to-restore-time 180