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Cisco Prime Network 4.3.2 User Guide
Appendix C      Event Correlation Examples
  Correlation Scenarios
Figure C-30 Device Unreachable on CE
EFP Down Correlation Scenarios
An Ethernet Flow Point (EFP) is a forwarding decision point in the PE switch or router that gives 
network designers the flexibility to make many Layer 2 flow decisions at the interface level. Many EFPs 
can be configured on a single physical port. These EFPs can be configured on any Layer 2 traffic port 
(usually on the UNI port). Each EFP manipulates the frames that enter it in a different manner and makes 
different forwarding decisions.
EFP Down Correlation Example 1
Figure C-31 provides an example of devices with EFP provisioning.
Figure C-31 EFP Down Example 1
In this example, service instances 900 and 901 are configured on port Gi4/3.
Route
Reflector
PEPE
CE
Device
Unreachable
Management
247293
7201-P1
10.56.101.1266504E-PE3
10.56.101.133
Fa0/0
Gi0/3Gi4/3 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
The physical link (Gi0/3 < > Gi4/3) is shut down. The expected alarm hierarchy:
Link down
–EFP down
–Link down syslogs
–Other related faults
EFP Down Correlation Example 2
Figure C-32 provides an example of devices with EFPs and a pseudowire provisioned.
Figure C-32 EFP Down Example 2
Service instances 900 and 901 are configured on port Gi4/3, and a local pseudowire is configured 
between Gi4/3 900 and Gi4/3 901 (local switching). 
Service instance 900 is shut down. The expected alarm hierarchy:
EFP down due to administrative down
–EFP down syslogs
–Local switching down
–Other related faults
EFP Down Correlation Example 3
Example 3 also uses Figure C-32. Service instance 900 is configured on port Gi4/3 and connects to a 
pseudowire through a bridge domain.
Service instance 900 is shut down. The expected alarm hierarchy:
EFP down due to administrative down
–EFP syslogs 
–Pseudowire tunnel down
–Other related faults
PW
247294
7201-P1
10.56.101.1266504E-PE3
10.56.101.133
Fa0/0
Gi0/3Gi4/3 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
EFP Down Correlation Example 4
Example 4 also uses Figure C-32. Service instance 900 is configured on port Gi4/3 and connects to a 
pseudowire through a bridge domain.
Generate traffic to switch the service instance status to error disabled. The expected alarm hierarchy:
EFP down due to error disabled
–EFP syslogs 
–Pseudowire tunnel down
–Other related faults
HSRP Scenarios
These topics describe scenarios that can generate HSRP alarms:
HSRP Alarms, page C-31
HSRP Example, page C-31
HSRP Alarms
When an active Hot Standby Router Protocol (HSRP) group’s status changes, a service alarm is 
generated and a syslog is sent.
NoteHSRP group information can be viewed in the inventory window of Prime Network NetworkVision.
HSRP Example
In Figure C-33, the link between Router 2 and Switch 2 is shut down, causing the HSRP standby group 
on Router 3 to become active, and a Link Down service alarm to be generated. The primary HSRP group 
on Router 2 is no longer active. A service alarm is generated and correlated to the Link Down alarm. 
Router 2 also sends a syslog which is correlated to the Link Down alarm.
The secondary HSRP group configured on Router 3 now changes from standby to active. This network 
event triggers an IP-based active flow with the destination being the virtual IP address configured in the 
HSRP group. When the flow reaches its destination, a service alarm is generated and correlated to the 
Link Down alarm. Router 3 also sends a syslog that is correlated to the Link Down alarm.
Table C-1 HSRP Service Alarms
Alarm Ticketable?Correlation 
allowed? Correlated to Severity
Primary HSRP interface is not active/Primary 
HSRP interface is activeYes No Can be correlated to several 
other alarms; for example, link 
downMajor
Secondary HSRP interface is active/Secondary 
HSRP interface is not activeYes No Can be correlated to several 
other alarms; for example, link 
downMajor 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
Figure C-33 Example
In this case, the system provides the following report:
Root cause: [Link Down, Router 2 < > Switch 2]
Correlated events:
–[Primary HSRP Interface is Not Active, Router 2]
%HSRP-6-STATECHANGE: FastEthernet0/0 Grp 1 state Active -> Speak (source: 
Router 2)
–[Secondary HSRP Interface is Active, Router 3]
%STANDBY-6-STATECHANGE: Ethernet0/0 Group 1 state Standby -> Active (source: 
Router 3)
IP Interface Failure Scenarios
These topics describe scenarios that can generate IP interface failures: 
Interface Status Down Alarm, page C-32
All IP Interfaces Down Alarm, page C-34
IP Interface Failure Examples, page C-34
Interface Status Down Alarm
Alarms related to subinterfaces (for example, a Line Down trap or syslog) are reported on IP interfaces 
configured above the relevant subinterface. This means that in the system, subinterfaces are represented 
by the IP interfaces configured above them. All events sourcing from subinterfaces without a configured 
IP interface are reported on the underlying Layer 1. 
Router 5
10.222.1.5Router 10
10.222.1.10
Router 3
10.222.1.3Router 2
110.110.110.1100/0
10/200.2.5
Switch 3
10.200.2.6
Switch 5
10.200.2.7Switch 2
10.200.2.4
4/14/2
4/30/23
0/3
0/2
0/1 0/1
0/21 Ethernet0/0
10.200.2.2
0/0
10.200.2.30/0
10.200.1.22
10.200.1.21
0/2 HSRP10.222.1.2
Ser 0/0/100
10.222.1.1
Ser 0/0/55
10.222.1.2
Ser 0/0/101P-2
P-3P-1
Frame-Relay
0/0 MAR
10.222.1.1
192.168.2.99
to Network 2.2
180450 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
An Interface Status Down alarm is generated when the status of an IP interface (whether over an 
interface or a subinterface) changes from up to down or any other nonoperational state (seeTa b l e C - 2). 
All events sourced from the subinterfaces correlate to this alarm. In addition, an All IP Interfaces Status 
Down alarm is generated when all the IP interfaces above a physical port change state to down. 
The alarm’s description includes the full name of the IP interface, for example Serial0.2 (including the 
identifier for the subinterface if it is a subinterface), and the alarm source points to the IP interface (and 
not to Layer 1).
All syslogs and traps indicating changes in subinterfaces (above which an IP address is configured) 
correlate to the Interface Status Down alarm. The source of these events is the IP interface. Syslogs and 
traps that indicate problems in Layer 1 (that do not have a subinterface qualifier in their description) are 
sourced to Layer 1.
NoteIf a syslog or trap is received from a subinterface that does not have an IP interface configured above it, 
the source of the created alarm is the underlying Layer 1.
For example:
Line Down trap (for subinterface)
Line Down syslogs (for subinterface)
For events that occur on subinterfaces: 
When sending the information northbound, the system uses the full subinterface name in the 
interface name in the source field, as described in the ifDesc/ifName OID (for example, Serial0/0.1 
and not Serial0/0 DLCI 50). 
The source of the alarm is the IP interface configured above the subinterface.
If IP is not configured on the interface, the source is the underlying Layer 1.
If the main interface goes down, all related subinterface traps and syslogs are correlated as child tickets 
to the main interface parent ticket.
The following technologies are supported:
Frame Relay/HSSI
AT M
Ethernet, Fast Ethernet, Gigabit Ethernet
Packet over SONET (POS)
Channelized Optical Carrier (CHOC)
Table C-2 Interface Status Down Alarm
Name Description Ticketable Correlation allowed Correlated to Severity
Interface 
Status 
Down/UpSent when an IP interface 
changes operational status to 
down/upYes Yes Link Down/Device 
UnreachableMajor 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
Correlation of Syslogs and Traps
Upon receipt of a trap or syslog for the subinterface level, Cisco ANA immediately polls the status of 
the relevant IP interface and creates a polled parent event (such as Interface Status Down). The trap or 
syslog is correlated to this alarm.
In a multipoint setup when only some circuits under an IP interface go down do not cause the state of 
the IP interface to change to down, Cisco ANA does not create an Interface Status Down alarm. All 
circuit down syslogs correlate by flow to the possible root cause, such as Device Unreachable on a CE 
device. 
All IP Interfaces Down Alarm
When all IP interfaces configured above a physical interface change their state to down, the All 
IP Interfaces Down alarm is sent.
When at least one of the IP interfaces changes its state to up, a clearing (Active IP Interface Found) 
alarm is sent.
The Interface Status Down alarm for each of the failed IP interfaces is correlated to the All 
IP Interfaces Down alarm.
NoteIf an All IP Interfaces Down alarm is cleared by the Active IP Interfaces Found alarm, but some 
correlated Interface Status Down alarms still exist for some IP interfaces, the severity of the parent ticket 
is the highest severity among all the correlated alarms. For example, if an Interface Status Down alarm 
is uncleared, the severity of the ticket remains major, despite the Active IP Interface Found alarm having 
a cleared severity.
For more information, see Ta b l e C - 3.
The All IP Interfaces Down alarm is sourced to the Layer 1 component. All alarms from the other side 
(such as Device Unreachable) correlate to the All IP Interfaces Down alarm.
IP Interface Failure Examples
NoteIn the following examples, it is assumed that the problems that result in the unmanaged cloud, or the 
problems that occurred on the other side of the cloud (such as an unreachable CE device from a PE 
device) cause the relevant IP interfaces’ state to change to down. This, in turn, causes the Interface Status 
Down alarm to be sent. 
If this is not the case, as in some Ethernet networks, and there is no change to the state of the IP interface, 
all the events on the subinterfaces that are capable of correlation flow will try to correlate to other 
possible root causes, including Cloud Problem.
Table C-3 All IP Interfaces Down
Name Description Ticketable Correlation allowed Correlated to Severity
All IP Interfaces 
Down/Active IP 
Interfaces FoundSent when all IP interfaces 
configured above a physical port 
change their operational status to 
down.Yes Yes Link Down Major 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
Interface Example 1
Figure C-34 represents an environment with multipoint connectivity between a PE and number of CEs 
through an unmanaged Frame Relay network. All CEs (Router2 and Router3) have logical connectivity 
to the PE through a multipoint subinterface on the PE (Router10). The keepalive option is enabled for 
all circuits. A link is disconnected inside the unmanaged network, causing all CEs to become 
unreachable. 
Figure C-34 Interface Example 1
The following failures are identified in the network: 
A Device Unreachable alarm is generated for each CE.
An Interface Status Down alarm is generated for the multipoint IP interface on the PE.
The following correlation information is provided:
The root cause is Interface Status Down.
All Device Unreachable alarms are correlated to the Interface Status Down alarm on the PE.
Interface Example 2
Figure C-35 represents an environment with point-to-point connectivity between a PE and a CE through 
an unmanaged Frame Relay network. CE1 became unreachable, and the status of the IP interface on the 
other side (on PE1) changed to down. The keepalive option is enabled. The interface is shut down 
between the unmanaged network and CE1.
Interface Serial0/0.100
point-to-point
10.200.1.2
Interface Serial0/0.101
point-to-point
10.200.1.3Interface Serial0/0.55
multipoint
10.200.1.10 Unreachable
Router2
10.222.1.2
Unreachable
Router2
10.222.1.3Frame Relay
cloudMultipoint
connectivity
Router10
10.222.1.10
180434
Multipoint 
IP interface
state down 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
Figure C-35 Interface Example 2
The following failures are identified in the network:
A Device Unreachable alarm is generated on the CE.
An Interface Status Down alarm is generated on the PE.
The following correlation information is provided:
The root cause is Device Unreachable:
–The Interface Status Down alarm is correlated to the Device Unreachable alarm.
–The syslogs and traps for the related subinterfaces are correlated to the Interface Status Down 
alarm.
Interface Example 3
Figure C-36 represents an environment in which the failure of multiple IP interfaces occurs above the 
same physical port (mixed point-to-point and multipoint Frame Relay connectivity). CE1 (Router2) has 
a point-to-point connection to PE1 (Router10). CE1 and CE2 (Router3) have multipoint connections to 
PE1. The IP interfaces on PE1 that are connected to CE1 and CE2 are all configured above Serial0/0. 
The keepalive option is enabled. A link is disconnected inside the unmanaged network, causing all CEs 
to become unreachable.
Figure C-36 Interface Example 3
Interface Serial1/0.500
point-to-point
102.0.0.2
Interface Serial1/0.100
point-to-point
102.0.0.1 Unreachable
CE1
60.60.60.4
Frame Relay
cloud Point-to-point
connectivity
PE1
80.80.80.69
180435
Point-to-point
IP interface
state unknown
Point-to-point
IP interface
state downRouting protocol
neighbor down syslog
(BGF, OSPF)
Interface Serial0/0.100
point-to-point
10.200.1.2
Interface Serial0/0.100
point-to-point
10.200.3.3Interface Serial0/0.100
point-to-point
10.200.3.10 Interface Serial0/0.101
point-to-point
10.200.1.3Interface Serial0/0.55
multipoint
10.200.1.10 Unreachable
Router2
10.222.1.2
CE-1
Unreachable
Router3
10.222.1.3
CE-2Frame Relay
cloud Mixed multipoint and
point-to-point
connectivity
Router10
10.222.1.10
PE-1
180436
All IP interfaces
above Serial0/0 change
state to down 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
The following failures are identified in the network:
All the CEs become unreachable.
An Interface Status Down alarm is generated for each IP interface above Serial0/0 that has failed.
The following correlation information is provided:
The root cause is All IP Interfaces Down on Serial0/0 port:
–The Interface Status Down alarms are correlated to the All IP Interfaces Down alarm.
–The Device Unreachable alarms are correlated to the All IP Interfaces Down alarm.
–The syslogs and traps for the related subinterfaces are correlated to the All IP Interfaces Down 
alarm.
Interface Example 4
Figure C-37 represents an environment in which the failure of multiple IP interfaces occurs above the 
same physical port (mixed point-to-point and multipoint Frame Relay connectivity). CE1 (Router2) has 
a point-to-point connection to PE1 (Router10). CE1 and CE2 (Router3) have multipoint connections to 
PE1. The IP interfaces on PE1 that are connected to CE1 and CE2 are all configured above Serial0/0. 
The keepalive option is enabled. 
A link is disconnected inside the unmanaged network, causing all CEs to become unreachable. When a 
Link Down occurs, whether or not it involves a cloud, the link failure is considered to be the most 
probable root cause for any other failure. In this example, a link is disconnected between the unmanaged 
network and the PE.
Figure C-37 Interface Example 4
The following failures are identified in the network:
A Link Down alarm is generated on Serial0/0.
A Device Unreachable alarm is generated for each CE.
An Interface Status Down alarm is generated for each IP interface above Serial0/0.
An All IP Interfaces Down alarm is generated on Serial0/0.
The following correlation information is provided:
The Device Unreachable alarms are correlated to the Link Down alarm.
The Interface Status Down alarm is correlated to the Link Down alarm.
Interface Serial0/0.100
point-to-point
10.200.1.2
Interface Serial0/0.101
point-to-point
10.200.1.3Interface Serial0/0.55
multipoint
10.200.1.10 Unreachable
Router2
10.222.1.2
Unreachable
Router3
10.222.1.3Frame Relay
cloud Mixed multipoint and
point-to-point
connectivity
Router10
10.222.1.10
180437
All IP interfaces
above Serial0/0 change
state to down
Link is down 
						

							 
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Appendix C      Event Correlation Examples
  Correlation Scenarios
The All IP Interfaces Down alarm is correlated to the Link Down alarm.
All the traps and syslogs for the subinterfaces are correlated to the Link Down alarm.
Interface Example 5
Figure C-38 represents an environment in which a PE1 device has multipoint connectivity, one of the 
circuits under the IP interface has gone down, and the CE1 device has become unreachable. The status 
of the IP interface has not changed and other circuits are still operational.
Figure C-38 General Interface Example
The following failures are identified in the network:
A Device Unreachable alarm is generated on CE1.
A syslog alarm is generated, notifying the user about a circuit down.
The following correlation information is provided: 
Device Unreachable on the CE—The syslog alarm is correlated by flow to the Device Unreachable 
alarm on CE1.
ATM Failure Examples
Examples involving ATM technology have the same result as the examples in IP Interface Failure 
Examples, page C-34, assuming that a failure in an unmanaged network causes the status of the 
IP interface to change to down (ILMI is enabled).
Ethernet, Fast Ethernet, and Gigabit Ethernet Examples
This section includes the following examples:
A CE becomes unreachable due to a failure in the unmanaged network (see Interface Example 6, 
page C-39).
A link down on a PE results in a CE becoming unreachable (see Interface Example 7, page C-39).
PE1
180440
CE1   unreachable
Circuit
down
syslog CE2
CE3Mixed multipoint
and point-to-point
connectivity
Cloud