Cisco Systems 3.6 specifications Vne

Chapter 2 Fault Detection and Isolation

Unreachable Network Elements

Table 2-1		Unreachable Network Elements (continued)
VNE Type	Checks reachability using		When the NE fails to respond	When the NE is reachable
Generic	•	SNMP only (default).	General polling is suspended, and a VNE	• General polling is restarted.
VNE		During the SNMP test the	Unreachable alarm is sent to the	• The first time the VNE is
		unit’s “SNMP get” the	Cisco ANA Gateway. Only the
					started, all the commands are
		sysoid of the NE and	reachability tests are executed thereafter to
					submitted to the queue, and the
		expects to receive a	detect when the device is reachable again.
					collector initiates an
		response
			If more than one protocol is used, it is		immediate session with the
		or	enough for one of them to become		NE. The commands are sent to
	•	SNMP only (default),	unreachable in order to generate the alarm.		the NE in a serial fashion.
			The alarm is generic to all the protocols.
		and adding an ICMP test.		•	The alarm is cleared.
Full VNE	•	SNMP only (default).	General polling is suspended, and a VNE	• The first time the VNE is
		During the SNMP	Unreachable alarm is sent to the		started, all the commands are
		reachability test, the	Cisco ANA Gateway. Only the		submitted to the queue and the
		VNE polls the device’s	reachability tests are executed thereafter to		collector initiates an
		SysOID MIB using a	detect when the device is reachable again.		immediate session with the
		standard “SNMP Get”	If more than one protocol is used, it is		NE. The commands are sent to
		command, and expects to			the NE in a serial fashion.
			enough for one of them to become
		receive a response	unreachable in order to generate the alarm.	•	The alarm is cleared.
		or	The alarm is generic to all the protocols.
	•	SNMP only (default),
		and adding ICMP and
		Telnet. During the Telnet
		test the unit sends
		"Enter" via the open
		session and expects to get
		a prompt back.

Each of these scenarios have two possible settings in the registry, namely:

•track reachability (true/false). The default is true.

When this parameter is true reachabilty is tracked according to the specific protocol, for example, ICMP, SNMP, Telnet, and so on.

When this parameter is false then the test is not performed.

•lazy reachability (true/false). The default is false. This parameters determines whether there is a dedicated reachability command ‘in-charge’ of tracking reachability or whether reachability is determined by the regular polled commands.

When this parameter is true reachability is based on polling, and a dedicated command not activated.

When this parameter is false a dedicated SNMP command is activated, and this test verifies the response from a specific SNMP oid (sysoid is the default that can be changed).

Note Changes to the registry should only be carried out with the support of Cisco Professional Services.

Cisco Active Network Abstraction Fault Management User Guide, Version 3.6 Service Pack 1

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