How CA Spectrum interface Threshold Exceeded alarm calculations can be greater than 100%
Article ID: 56497
Updated On:
Products
Issue/Introduction
A CA Spectrum interface threshold alarm shows values greater than 100%. The following is an example:
| Critical | Sep 4, 2014 1:22:37 PM EDT | Device | Threshold Exceeded for IN LOAD for an unacceptable duration. The threshold value is 70 %, and the current value is 22891 %. Model Type = Gen_IF_Port, Name = Device. | 0x1133b |
Check to see if there are associated 0x10d80 events are similar to the following:
| Sep 4, 2014 6:51:16 AM EDT | Device | Problem detected with data in the Interface Performance Calculations SOURCE DATA ************************************ Initial X_IN_OCTETS: 234538471403 Final X_IN_OCTETS: 234538475706 Initial X_OUT_OCTETS: 106579090705 Final X_OUT_OCTETS: 106579095716 Initial X_IN_ERROR_PKTS: 0 Final X_IN_ERROR_PKTS: 0 Initial X_OUT_ERROR_PKTS: 0 Final X_OUT_ERROR_PKTS: 0 Initial X_IN_NO_RESOURCE_PKTS: 0 Final X_IN_NO_RESOURCE_PKTS: 0 Initial X_OUT_NO_RESOURCE_PKTS: 0 Final X_OUT_NO_RESOURCE_PKTS: 0 Initial X_IN_NUCAST_PKTS: 0 Final X_IN_NUCAST_PKTS: 0 Initial X_OUT_NUCAST_PKTS: 0 Final X_OUT_NUCAST_PKTS: 0 Initial X_IN_MCAST_PKTS: 2963948 Final X_IN_MCAST_PKTS: 2963949 Initial X_OUT_MCAST_PKTS: 0 Final X_OUT_MCAST_PKTS: 0 Initial X_IN_BCAST_PKTS: 0 Final X_IN_BCAST_PKTS: 0 Initial X_OUT_BCAST_PKTS: 0 Final X_OUT_BCAST_PKTS: 0 Initial X_IN_UCAST_PKTS: 395133432155898 Final X_IN_UCAST_PKTS: 395137727123232 Initial X_OUT_UCAST_PKTS: 642049395 Final X_OUT_UCAST_PKTS: 642049435 Initial X_IN_UNKNOWN_PROTOS: 0 Final X_IN_UNKNOWN_PROTOS: 0 Initial X_SYSTEM_UP_TIME: 2415725744 Final X_SYSTEM_UP_TIME: 2415726786 Delta SYSTEM_UP_TIME: 1042 PREVIOUS IFTYPE: 6 CURRENT IFTYPE: 6 PREVIOUS X_LOW_BANDWIDTH: 10000000 CURRENT X_LOW_BANDWIDTH: 10000000 PREVIOUS X_HIGH_BANDWIDTH: 10 CURRENT X_HIGH_BANDWIDTH: 10 CALCULATED METRICS *************************************** PREVIOUS BIT_RATE_IN: 2824 PREVIOUS BIT_RATE_OUT: 2982 CURRENT BIT_RATE_IN: 3303 CURRENT BIT_RATE_OUT: 3847 PREVIOUS LOAD_TOTAL: 0 PREVIOUS LOAD_IN: 0 PREVIOUS LOAD_OUT: 0 CURRENT LOAD_TOTAL: 659495 CURRENT LOAD_IN: 659495 CURRENT LOAD_OUT: 0 PREVIOUS IN_THROUGHPUT_PKTS: 3 PREVIOUS OUT_THROUGHPUT_PKTS: 3 PREVIOUS TOTAL_THROUGHPUT_PKTS: 6 CURRENT IN_THROUGHPUT_PKTS: 412184964 CURRENT OUT_THROUGHPUT_PKTS: 3 CURRENT TOTAL_THROUGHPUT_PKTS: 412184967 PREVIOUS PERCENT_ERROR_PKTS: 0 CURRENT PERCENT_ERROR_PKTS: 0 PREVIOUS PERCENT_DISCARDED_PKTS: 0 CURRENT PERCENT_DISCARDED_PKTS: 0 INTERNAL SOURCES ATTRIBUTES ****************************** 0x12db6 0x12db2 0x12db4 0x12db8 0x12db7 0x12db3 0x12db5 0x130d1 0x12dfa 0x12db0 0x12dae 0x12daa 0x12dac 0x12db1 0x12daf 0x12dab 0x12dad 0x12bb5 0x12bb4 0x220177 0x12df9 EXTERNAL SOURCES ATTRIBUTES: 0x11317 0x11318 0x11319 0x1131a 0x1131e 0x1131f 0x11321 0x11348 0x1134c 0x11f63 0x11f64 0x11f65 0x11f66 0x11f67 0x11f68 0x11f69 0x11f6a 0x11f6b 0x22001a 0x22001a 0x22005e |
0x10d80 |
The 0x10d80 event basically shows the user what data was used to compute load, load in and load out. Out of the box, when CA Spectrum initially models a device, CA Spectrum tests which counters (32 and 64 bit) a ports supports. It also checks when the model is reconfigured and once every 24 hours. If a port supports a 64 bit counter, CA Spectrum will use the 64 bit counter when computing load, load in and load out.
CA Spectrum uses the basic utilization formula defined in the etherStatsOctets attribute of RFC1757 as follows:
Delta_Pkts * (9.6 + 6.4) + (Delta_Octets * 0.8)
Utilization = ----------------------------------------------------------------- * 100,000
Delta_sysUpTime * bandwidth
In the above 0x10d80, you will notice very large numbers for X_IN_UCAST_PKTS which indicates the device supports the 64 bit counter for ucast packets:
Initial X_IN_UCAST_PKTS: 395133432155898
Final X_IN_UCAST_PKTS: 395137727123232
However, the bandwidth parameters are too small to compute 64 bit counters:
PREVIOUS X_LOW_BANDWIDTH: 10000000
CURRENT X_LOW_BANDWIDTH: 10000000
PREVIOUS X_HIGH_BANDWIDTH: 10
CURRENT X_HIGH_BANDWIDTH: 10
(X_HIGH_BANDWIDTH is taken from the ifHighSpeed attribute in the ifMib which is defined as "An estimate of the interface's current bandwidth in units of 1,000,000 bits per second.)
Knowing the values Spectrum uses to compute load, load in and load out from the 0x10d80 and the formula Spectrum uses to compute load, load in and load out from the etherStatsOctets attribute of RFC1757, you can manually compute the values to verify the CA Spectrum results.
Environment
Component:
Resolution
- If the device is modeled using SNMP V2 or V3, the "SNMP Community String" can be changed to use an SNMP V1 community string which will prevent access to the 64 bit counter attributes so CA Spectrum will only use the 32 bit counters.
- Contact the vendor.
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