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. The occurrence of an unrecoverable condition like Power Failure triggers Dying Gasp.

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.

Restrictions for Dying Gasp Support

  • Cisco 1000 Series Integrated Services Routers support the Power Failure Dying Gasp feature on selective PIDs.

  • Cisco 1000 Series Integrated Services Routers Power Failure Dying Gasp only support sending out Ethernet OAM packets.

  • Dying Gasp feature is not supported during a power loss, while a signal is initiated using jumbo frames with 10M of WAN line.

  • Inthe case of system reload or interface shutdown on the Cisco 4000 Series ISRs and Cisco 1100 Series ISRs running Cisco IOS-XE Everest Release 16.6.2, dying gasp packets are sent to peer routers. However, the system state is not captured in the system logs (syslogs) or SNMP traps.

  • This feature is supported on the following platforms:

    • C1101-4P

    • C1121/1161 non-WiFi SKUs

      • C1121-8PLTEP

      • C1121X-8PLTEP

      • C1121-8P

      • C1121X-8P

      • C1161-8P

      • C1161X-8P

      • C1161-8PLTEP

      • C1161X-8PLTEP

      • C1121-4PLTEP

      • C1121-4P

Information About Dying Gasp Through Ethernet OAM

Dying Gasp

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 OAM provides a mechanism for an OAM entity to convey these failure conditions to its peer via specific flags in the OAM PDU. One of the failure condition method to communicate is Dying Gasp, which indicates that an unrecoverable condition has occurred; for example, when an interface is shut down. This type of condition is vendor specific. A notification about the condition may be sent immediately and continuously.

How to Configure Dying Gasp Ethernet OAM

Dying Gasp Trap Support for Different SNMP Server Host/Port Configurations


Note
You can configure up to five different SNMP server host/port configurations.

Environmental Settings on the Network Management Server



setenv SR_TRAP_TEST_PORT=UDP port
setenv SR_UTIL_COMMUNITY=public
setenv SR_UTIL_SNMP_VERSION=v2c
setenv SR_MGR_CONF_DIR=Path to the executable snmpinfo.DAT file

The following example shows SNMP trap configuration on the host:



Router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#
Router(config)# snmp-server host 172.31.255.254 vrf Mgmt-intf version 2c public udp-port 6264
Router(config)#
Router(config)# ^Z
Router#

After performing a power cycle, the following output is displayed on the router console: 



Router#
System Bootstrap, Version 16.6(2r), RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1994-2017  by cisco Systems, Inc.
Current image running: Boot ROM0
Last reset cause: LocalSoft
C1111-8PLTELA platform with 4194304 Kbytes of main memory
rommon 1 > 

=======================================
Dying Gasp Trap Received for the Power failure event:
-----------------------------------------------------
  Trap on the Host
++++++++++++++

snmp-server host = 192.0.2.1 (nms1-lnx)  and SR_TRAP_TEST_PORT=6264 
/auto/sw/packages/snmpr/15.4.1.9/bin> /auto/sw/packages/snmpr/15.4.1.9/bin/traprcv
Waiting for traps.
Received SNMPv2c Trap:
Community: public
From: 192.0.2.2
snmpTrapOID.0 = ciscoMgmt.305.1.3.5.0.2
ciscoMgmt.305.1.3.6 = Dying Gasp - Shutdown due to power loss

Message Displayed on the Peer Router on Receiving Dying Gasp Notification


001689: *May 30 14:16:47.746 IST: %ETHERNET_OAM-6-RFI: The client on interface Gi0/0/0 has received a remote failure indication from its remote peer(failure reason = remote client power failure action = )

Displaying SNMP Configuration for Receiving Dying Gasp Notification

Use the show running-config command to display the SNMP configuration for receiving dying gasp notification: 


Router# show running-config | i snmp
snmp-server community public RW
snmp-server host 192.0.2.1 vrf Mgmt-intf version 2c public udp-port 6264
Router#

Configuration Examples for Dying Gasp Through Ethernet OAM

Example: Configuring SNMP Community Strings on a Router

Setting up the community access string to permit access to the SNMP: 



Router> enable
Router# configure terminal
Router(config)# snmp-server community public RW
Router(config)# exit

For more information on command syntax and examples, refer to the Cisco IOS Network Management Command Reference.

Example: Configuring SNMP-Server Host Details on the Router Console

Specifying the recipient of a SNMP notification operation: 



Router> enable
Router# configure terminal
Router(config)# snmp-server host X.X.X.XXX vrf mgmt-intf version 2c public udp-port 9800
Router(config)# exit

For more information on command syntax and examples, refer to the Cisco IOS Network Management Command Reference.

Configuring OAMPDU

With the new Dying Gasp feature in the Cisco 1000 Series Integrated Services 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

Feature Information for Dying Gasp Support

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1. Feature Information for Dying Gasp Support

Feature Name

Releases

Feature Information for

Dying Gasp

Cisco IOS XE Release 16.6.2

Ethernet OAM provides a mechanism for an OAM entity to convey failure conditions to its peer via specific flags in the OAM PDU. One of the failure condition method to communicate is Dying Gasp, which indicates that an unrecoverable condition has occurred; for example, when an interface is shut down. This type of condition is vendor specific. A notification about the condition may be sent immediately and continuously.