Daren Matthews

This recipe describes how to use SNMP to determine the traffic offered and drop rate for a QoS policy configured on a Cisco router.

The steps here describe which OIDs to interrogate in the CISCO-CLASS-BASED-QOS-MIB

STEP 1:

Get the SNMP ifIndex for the interface where the QoS policy is attached:
CiscoRouter#sh snmp mib ifmib ifindex | i GigabitEthernet0/1
GigabitEthernet0/1: Ifindex = 22

(or by using SNMP):
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.2.1.2.2 | grep -i GigabitEthernet0/1
RFC1213-MIB::ifDescr.22 = STRING: “GigabitEthernet0/1”

STEP 2:
Use the MIB Object cbQosCMName (1.3.6.1.4.1.9.9.166.1.7.1.1.1) to get the names of class-maps configured on the router:

snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.7.1.1.1

The output will show each class-map with its Index (i.e the cbQosConfigIndex):

root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.7.1.1.1
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.1025 = STRING: “class-default”
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.2159 = STRING: “VOICE”
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.2165 = STRING: “VIDEO”
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.2171 = STRING: “CRITICAL”
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.2181 = STRING: “PRODUCTIVITY”
RFC1155-SMI::enterprises.9.9.166.1.7.1.1.1.2187 = STRING: “BULK-TRANSFER”

Make a note of the values (e.g. 1025 for class-default), which is the cbQosConfigIndex.

STEP 3:
Use cbQosConfigIndex to get the cbQosPolicyIndex and cbQosObjectsIndex for individual class-maps:

Example for “class-default” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 1025’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2267 = Gauge32: 1025
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2275 = Gauge32: 1025

Example for “VOICE” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 2159’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2235 = Gauge32: 2159

Example for “VIDEO” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 2165’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2241 = Gauge32: 2165

Example for “CRITICAL” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 2171’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2247 = Gauge32: 2171

Example for “PRODUCTIVITY” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 2181’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2257 = Gauge32: 2181

Example for “BULK-TRANSFER” above:
root@Linux# snmpwalk -v2c -c communityname 10.0.200.12 1.3.6.1.4.1.9.9.166.1.5.1.1.2 | grep -i ‘Gauge32: 2187’
RFC1155-SMI::enterprises.9.9.166.1.5.1.1.2.2231.2263 = Gauge32: 2187

STEP 4:
Determine the offered traffic rate per class:
cbQosCMPrePolicyBitRate (for info refer to: http://oidref.com/1.3.6.1.4.1.9.9.166.1.15.1.1.7 )

RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2235 = Gauge32: 1064000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2241 = Gauge32: 1000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2247 = Gauge32: 308000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2257 = Gauge32: 2835000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2263 = Gauge32: 242000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2267 = Gauge32: 24557000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.7.2231.2275 = Gauge32: 29154000

Determine the drop rate per class:
cbQosCMDropBitRate (for info refer to: http://oidref.com/1.3.6.1.4.1.9.9.166.1.15.1.1.18 )
The bit rate of the drops per class as the result of all features that can produce drops (e.g., police, random detect, etc.)

RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2235 = Gauge32: 0
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2241 = Gauge32: 0
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2247 = Gauge32: 0
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2257 = Gauge32: 0
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2263 = Gauge32: 0
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2267 = Gauge32: 64000
RFC1155-SMI::enterprises.9.9.166.1.15.1.1.18.2231.2275 = Gauge32: 64000