user manual
Table Of Contents
- Cisco Active Network Abstraction Fault Management User Guide Version 3.6 Service Pack 1
- Contents
- About This Guide
- Fault Management Overview
- Fault Detection and Isolation
- CiscoANA Event Correlation and Suppression
- Advanced Correlation Scenarios
- Device Unreachable Alarm
- IP Interface Failure Scenarios
- Multi Route Correlation
- Generic Routing Encapsulation (GRE) Tunnel Down/Up
- BGP Process Down Alarm
- MPLS Interface Removed Alarm
- LDP Neighbor Down Alarm
- Correlation Over Unmanaged Segments
- Event and Alarm Configuration Parameters
- Impact Analysis
- Supported Service Alarms
- Event and Alarm Correlation Flow
2-2
Cisco Active Network Abstraction Fault Management User Guide, Version 3.6 Service Pack 1
OL-14284-01
Chapter 2 Fault Detection and Isolation
Unreachable Network Elements
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.
Generic
VNE
• SNMP only (default).
During the SNMP test the
unit’s “
SNMP get” the
sysoid of the NE and
expects to receive a
response
or
• SNMP only (default),
and adding an ICMP test.
General polling is suspended, and a VNE
Unreachable alarm is sent to the
Cisco ANA Gateway. Only the
reachability tests are executed thereafter to
detect when the device is reachable again.
If more than one protocol is used, it is
enough for one of them to become
unreachable in order to generate the alarm.
The alarm is generic to all the protocols.
• General polling is restarted.
• The first time the VNE is
started, all the commands are
submitted to the queue, and the
collector initiates an
immediate session with the
NE. The commands are sent to
the NE in a serial fashion.
• The alarm is cleared.
Full VNE
• SNMP only (default).
During the SNMP
reachability test, the
VNE polls the device’s
SysOID MIB using a
standard “
SNMP Get”
command, and expects to
receive a response
or
• 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.
General polling is suspended, and a VNE
Unreachable alarm is sent to the
Cisco ANA Gateway. Only the
reachability tests are executed thereafter to
detect when the device is reachable again.
If more than one protocol is used, it is
enough for one of them to become
unreachable in order to generate the alarm.
The alarm is generic to all the protocols.
• The first time the VNE is
started, all the commands are
submitted to the queue and the
collector initiates an
immediate session with the
NE. The commands are sent to
the NE in a serial fashion.
• The alarm is cleared.
Table 2-1 Unreachable Network Elements (continued)
VNE Type Checks reachability using When the NE fails to respond When the NE is reachable