Dying Gasp Through Ethernet OAM

Dying Gasp is a final notification, or a signal sent by a device when it is about to lose power. The device sends a signal to alert a peer device, which identifies and responds to the power related issues.

Ethernet Operations, Administration, and Maintenance (OAM) is a set of protocols that monitors and manages Ethernet networks. For interfaces where Ethernet OAM is enabled, the device sends a Dying Gasp message using an Ethernet OAM protocol. It supports the generation of the Ethernet OAM Dying Gasp packets to notify the remote peer device that the local device is having a power failure.

This type of condition is vendor specific. An Ethernet Operations, Administration, and Maintenance (OAM) notification about the condition may be sent immediately.

Prerequisites for Dying Gasp Support

  • The ethernet OAM is enabled by default on L3 interface.

    The Dying Gasp feature can be disabled using the command:
    Router(config-if)#ethernet oam mode passive
    It can be enabled again by using this command: CLI:
    Router (config-if)#ethernet oam mode active
  • Ethernet OAM is sent out only when there is power loss.

Restrictions for Dying Gasp Support

  • The Power Failure Dying Gasp feature is only supported on C8355-G2 routers.

  • C8355-G2 routers Power Failure Dying Gasp only support sending out Ethernet OAM packets.

Dying Gasp using Ethernet OAM

One of the OAM features as defined by IEEE 802.3ah is Remote Failure Indication, which helps in detecting faults in Ethernet connectivity that are caused by slowly deteriorating quality. Ethernet Operations, Administration, and Maintenance (OAM) protocol sends specific flags in the OAM Protocol Data Unit (PDU) to convey failure conditions. This feature is vendor-specific and is supported on C8355-G2 routers. A notification about the condition may be sent immediately and continuously to indicate the device is about to lose power.

Configuring OAMPDU

With the Dying Gasp feature in the C8355-G2 Routers, you can configure the Code field value in the OAMPDU frame. The allowed values to be configured are:

  • Information: Indicates the OAM package is transferring local or remote information data. 0x00 stands for Information OAMPDU.

  • Organization specific: Indicates that this is reserved for vendors. Each vendor can use this code to carry customized data. 0xFE stands for organization specific OAMPDU which is the default type set for OAMPDU.

Configuring information OAMPDU

Router# enable
	Router# configure terminal
Router(config)# interface GigabitEthernet0/0/0
Router(config-if)# ethernet oam dying-gasp type information
Router(config-if)# exit
Router(config)# exit
Router#show ethernet oam status interface GigabitEthernet0/0/0
GigabitEthernet0/0/0
General
-------
  Admin state:           enabled
  Mode:                  passive
  Type:                  information
  PDU max rate:          10 packets per second
  PDU min rate:          1 packet per 1000 ms
… …

Configuring organization specific OAMPDU

Router# enable
	Router# configure terminal
Router(config)# interface GigabitEthernet0/0/0
Router(config-if)# ethernet oam dying-gasp type organization
Router (config-if)# exit
Router(config)# exit
Router# show ethernet oam status interface GigabitEthernet0/0/0
GigabitEthernet0/0/0
General
-------
  Admin state:           enabled
  Mode:                  passive
  Type:                  organization
  PDU max rate:          10 packets per second
  PDU min rate:          1 packet per 1000 ms