Tag Archives: QoS

GNS3 Labs: BGP triggered rate limiting and less-than-best-effort (LBE) with QPPB

This post is part of a series about “ISP Security Tools and Techniques“; in this series I talk about some (I think) useful practices:

1. Remote Triggered Black Holing

2. BGP Customer triggered black holing

3. BGP triggered rate limiting and less-than-best-effort (LBE) with QPPB

4. Source-based RTBH with Unicast Reverse Path Forwarding (uRPF)

Stay tuned! 😉

As I already wrote in my previous posts, an ISP can provide their customers some useful tools to mitigate (D)DoS attacks: Remote Triggered Black Holing and its NOC-independent version, Customer triggered black holing are tools that, once identified attacked hosts or networks, let us to stop malicious traffic at the provider’s edge.

Anyway, when we drop traffic toward attacked hosts, we can’t investigate the attack anymore; we would need a tool which allowed us to analyze traffic and, in the meantime, that would avoid wasting network resources. Our (dear) provider could provide it by implementing rate limiting and less-than-best-effort services using QoS Policy Propagation via BGP (QPPB).

Read more …

Zabbix tool for Cisco Class-Based QoS monitoring

As said in my previous post about this topic, I’ve made a small Perl script to build Zabbix configuration for Cisco Class-Based QoS monitoring.

As first, I have to say I’m NOT a Perl programmer, so I think real Perl programmers will find my script a shocking jumble of code. I apoligize!

Any suggestion would be appreciate!


This is a beta version of the script: use it at your own risk!


You can find the script here. It requires Net::SNMP module (“apt-get install libnet-snmp-perl” on Debian to install it).

What it does

This script lets you to monitor Cisco QoS stats and counters in your Zabbix NMS using the builtin SNMP agent. You can store the same stats you can see with a “show policy-map interface …” command and have graphs built on them.

You can get values from class-maps, match statements, traffic policing and shaping.

How it works

When you run the script (with proper arguments!) it walks through the SNMP MIB of your device and discovers QoS policies layout; then, it builds Zabbix items and graphs about objects it finds.

How to use it

Unfortunately Zabbix has a quite complex database structure, so I preferred to use the builtin import/export feature instead of manipulating tables directly in my script to add items and graphs.

The output is formatted on the basis of the Zabbix XML configuration file.

To use the script you have to export your Cisco device configuration from the Zabbix Configuration / Export/Import menu, then merge the script’s output within the <host> XML element and, finally, import the new XML file into Zabbix.

Usage is pretty simple:


Here, HOST is the Cisco device IP address, SNMP_COMMUNITY is the SNMP read community (default to public), and OBJECTS_TO_MONITOR is a list of one or more objects you want to add to Zabbix (objects are class-maps, match statements, traffic policing and traffic shaping). More options are available: you can see the full help just running ./ciscocbqos without any argument.

For example, if you want to monitor traffic-shaping on router at you can run

./ciscocbqos -c myreadcommunity -o /root/qos +trafficshaping

Once done, you will find /root/qos.items and /root/qos.graphs files containing a scrap of Zabbix XML file to merge with your existing configuration. At this point all you have to do is to put qos.items and qos.graphs content inside the <host> XML element of the exported Zabbix file (line 17 and 18 of the following example).

&lt;?xml version=&quot;1.0&quot;?&gt;
&lt;zabbix_export version=&quot;1.0&quot; date=&quot;21.04.09&quot; time=&quot;17.59&quot;&gt;
		&lt;host name=&quot;MYCISCODEVICE&quot;&gt;
			qos.items content goes here
			qos.graphs content goes here

Zabbix keys and SNMP indexes

As you know Zabbix uses keys to uniquely identify items within a host; SNMP agent gets those values from devices and stores them using their keys. This script can be ran in two ways to build Zabbix keys: with or without the +p option.

You should use the +p option only if your device has the “snmp mib persist cbqos” command in the configuration. This option lets the script to build keys based on the SNMP indexes: if you use the “snmp mib persist cbqos” command indexes are maintained after device restart.

With no “snmp mib persist cbqos” command in the config, you should run the script without the +p option, in order to build Zabbix keys on the basis of a hash of items descriptions. In this scenario you have to run the script every time you restart your device, cause SNMP indexes will change and Zabbix items will be outdated.

The cbqos keyword was added starting from IOS 12.4(4)T.

Some graphs

Here are some Zabbix graphs generated using the script:

Traffic policing

Traffic policing

Traffic policing class-map

Traffic policing class-map

Interface overview (stack of class-map)

Interface overview (stack of class-map)

Cisco Class-Based QoS SNMP MIB and statistics monitor for NMS

As stated in the official CISCO-CLASS-BASED-QOS-MIB file, Cisco Class-Based QoS MIB “provides read access to Quality of Service (QoS) configuration and statistics information for Cisco platforms that support the Modular Quality of Service Command-line Interface“.

In other words, the integration of this MIB in a SNMP-based NMS lets you to monitor all the values you can see with the show policy-map IOS command.

This MIB has not a so straightforward structure as other MIBs have, so integration with NMS can be a little diffcult.

Let’s take a deeper look at its structure; in a future post I’ll show how to use this information to monitor IOS QoS statistics in Zabbix.

We’ll use the following trivial IOS configuration for our examples:

class-map match-any NonLocal
 match access-group 10
class-map match-all ICMP
 match protocol icmp
policy-map CPP
  description Applied to control plan - In
 class NonLocal
   police cir 8000
     conform-action transmit
     exceed-action drop
policy-map LAN_Out
  description Applied to fa0/0 - Out
 class ICMP
  bandwidth 10
 class class-default
interface FastEthernet0/0
 ip address
 service-policy output LAN_Out
access-list 10 deny
access-list 10 permit any
 service-policy input CPP

In this MIB informations are stored on a lot of tables:

  • cbQosServicePolicyTable and cbQosObjectsTable define QoS policies layout;
  • cbQosXXXCfgTable tables define configuration details for the objects (ClassMap, PolicyMap, Match statements…);
  • cbQosXXXStatsTable tables define runtime statistics for the same objects.

As first, we have to look at cbQosServicePolicyTable: here we find bindings between policy-maps and interfaces, as in the service-policy command:


# snmpwalk -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosIfType.1043 = INTEGER: mainInterface(1)
CISCO-CLASS-BASED-QOS-MIB::cbQosIfType.1099 = INTEGER: controlPlane(5)
CISCO-CLASS-BASED-QOS-MIB::cbQosPolicyDirection.1043 = INTEGER: output(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosPolicyDirection.1099 = INTEGER: input(1)
CISCO-CLASS-BASED-QOS-MIB::cbQosAtmVPI.1043 = Gauge32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosAtmVPI.1099 = Gauge32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosAtmVCI.1043 = Gauge32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosAtmVCI.1099 = Gauge32: 0

cbQosPolicyIndex is the table’s index (1043, 1099 in the previous example); it identifies the service-policy.

cbQosIfType defines the type of interface which the service-policy is applied to: mainInterface(1), subInterface(2), frDLCI(3), atmPVC(4), controlPlane(5), vlanPort(6).

cbQosPolicyDirection tells the direction of the traffic: input(1) and output(2).

Other parameters depend on cbQosIfType value and represent specific objects identifiers (ifIndex, DLCI, VPI/VCI, … ).

From the previous example we can see there are 2 service-policies, with ID 1043 and 1099, applied for output traffic to a physical interface with ifIndex 1, and for input traffic to the control-plane.

The second important table is cbQosObjectsTable, where all objects (class-map, match, set statements…) are stored, classified (cbQosObjectsType), identified within the configuration (cbQosConfigIndex) and related to the service-policy or other objects (cbQosParentObjectsIndex). Here we have a two-fields index: cbQosPolicyIndex and cbQosObjectsIndex:


# snmpwalk -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1043 = Gauge32: 1035
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1045 = Gauge32: 1029
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1047 = Gauge32: 1033
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1049 = Gauge32: 1037
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1051 = Gauge32: 1025
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1053 = Gauge32: 1027
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1085 = Gauge32: 1079
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1099 = Gauge32: 1063
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1101 = Gauge32: 1057
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1103 = Gauge32: 1061
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1105 = Gauge32: 1065
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1107 = Gauge32: 1025
CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1099.1109 = Gauge32: 1027
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1043 = INTEGER: policymap(1)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1045 = INTEGER: classmap(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1047 = INTEGER: matchStatement(3)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1049 = INTEGER: queueing(4)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1051 = INTEGER: classmap(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1053 = INTEGER: matchStatement(3)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1043.1085 = INTEGER: queueing(4)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1099 = INTEGER: policymap(1)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1101 = INTEGER: classmap(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1103 = INTEGER: matchStatement(3)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1105 = INTEGER: police(7)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1107 = INTEGER: classmap(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosObjectsType.1099.1109 = INTEGER: matchStatement(3)
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1043 = Gauge32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1045 = Gauge32: 1043
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1047 = Gauge32: 1045
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1049 = Gauge32: 1045
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1051 = Gauge32: 1043
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1053 = Gauge32: 1051
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1043.1085 = Gauge32: 1051
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1099 = Gauge32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1101 = Gauge32: 1099
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1103 = Gauge32: 1101
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1105 = Gauge32: 1101
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1107 = Gauge32: 1099
CISCO-CLASS-BASED-QOS-MIB::cbQosParentObjectsIndex.1099.1109 = Gauge32: 1107

cbQosConfigIndex let us to find configuration details about objects in other tables; service-policies have the same cbQosObjectsIndex as cbQosPolicyIndex. These config tables are cbQosObjectsType dependent: we have cbQosPolicyMapCfgTable, cbQosClassMapCfgTable, cbQosMatchStmtCfgTable… each object type has its own table, all referenced by cbQosConfigIndex.

Let’s see one of them…


# snmpwalk -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosPolicyMapDesc.1035 = STRING: Applied to fa0/0 - Out
CISCO-CLASS-BASED-QOS-MIB::cbQosPolicyMapDesc.1063 = STRING: Applied to control plan - In

We can see here our policy-maps, indexed by the cbQosConfigIndex values previously found on cbQosObjectsTable.

With the cbQosObjectsTable data we already have all informations we need to build an OID list for our NMS.

Assume we just need to monitor class-map offered rate and drop rate, as in the show policy-map interface | inc Class-map|offered. All per class-map statistics are collected on the cbQosCMStatsTable; as all stats table, it’s indexed by cbQosPolicyIndex and cbQosObjectsIndex. Take a look at the table:


# snmpwalk -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPktOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPktOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPktOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPktOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt.1043.1045 = Counter32: 8
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt.1043.1051 = Counter32: 1131
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt.1099.1101 = Counter32: 281
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt.1099.1107 = Counter32: 7016
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt64.1043.1045 = Counter64: 8
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt64.1043.1051 = Counter64: 1131
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt64.1099.1101 = Counter64: 281
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyPkt64.1099.1107 = Counter64: 7016
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByteOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByteOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByteOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByteOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte.1043.1045 = Counter32: 784
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte.1043.1051 = Counter32: 114630
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte.1099.1101 = Counter32: 69858
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte.1099.1107 = Counter32: 658800
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte64.1043.1045 = Counter64: 784
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte64.1043.1051 = Counter64: 114630
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte64.1099.1101 = Counter64: 69858
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyByte64.1099.1107 = Counter64: 658800
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1043.1051 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1099.1101 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1099.1107 = Gauge32: 1000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByteOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByteOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByteOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByteOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte.1043.1045 = Counter32: 784
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte.1043.1051 = Counter32: 114630
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte.1099.1101 = Counter32: 69668
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte.1099.1107 = Counter32: 658800
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte64.1043.1045 = Counter64: 784
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte64.1043.1051 = Counter64: 114630
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte64.1099.1101 = Counter64: 69668
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyByte64.1099.1107 = Counter64: 658800
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1043.1051 = Gauge32: 2000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1099.1101 = Gauge32: 2000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1099.1107 = Gauge32: 2000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPktOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPktOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPktOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPktOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt.1099.1101 = Counter32: 4
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt64.1043.1045 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt64.1043.1051 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt64.1099.1101 = Counter64: 4
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropPkt64.1099.1107 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByteOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByteOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByteOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByteOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte.1099.1101 = Counter32: 380
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte64.1043.1045 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte64.1043.1051 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte64.1099.1101 = Counter64: 380
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropByte64.1099.1107 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1043.1051 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1099.1101 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1099.1107 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPktOverflow.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPktOverflow.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPktOverflow.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPktOverflow.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt.1043.1045 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt.1043.1051 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt.1099.1101 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt.1099.1107 = Counter32: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt64.1043.1045 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt64.1043.1051 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt64.1099.1101 = Counter64: 0
CISCO-CLASS-BASED-QOS-MIB::cbQosCMNoBufDropPkt64.1099.1107 = Counter64: 0

We just need to select cbQosPolicyIndex and cbQosObjectsIndex values from cbQosObjectsTable where cbQosObjectsType = classmap(2) and attach them to the counter we need to monitor.

CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1043.1051 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1099.1101 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPrePolicyBitRate.1099.1107 = Gauge32: 1000 bits per second

CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1043.1051 = Gauge32: 2000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1099.1101 = Gauge32: 2000 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMPostPolicyBitRate.1099.1107 = Gauge32: 2000 bits per second

CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1043.1045 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1043.1051 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1099.1101 = Gauge32: 0 bits per second
CISCO-CLASS-BASED-QOS-MIB::cbQosCMDropBitRate.1099.1107 = Gauge32: 0 bits per second

To have more details about the ClassMap statements to which these stats are related we can look at their configuration: as first we need their cbQosConfigIndex:

# snmpget -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosConfigIndex.1043.1045 = Gauge32: 1029

With cbQosConfigIndex we can get class-map details; this is the cbQosCMCfgTable table:


# snmpwalk -v 2c -c public -m ALL .

CISCO-CLASS-BASED-QOS-MIB::cbQosCMName.1025 = STRING: class-default
CISCO-CLASS-BASED-QOS-MIB::cbQosCMInfo.1025 = INTEGER: matchAny(3)
CISCO-CLASS-BASED-QOS-MIB::cbQosCMInfo.1029 = INTEGER: matchAll(2)
CISCO-CLASS-BASED-QOS-MIB::cbQosCMInfo.1057 = INTEGER: matchAny(3)

We can easily get the class-map name:

# snmpget -v 2c -c public -m ALL .


Of course we can build NMS configuration including more details from both objects details and statistics.

Please note that, by default, indexes “are never reused between router reboots, even when changes are made to the QoS configuration“. This is stated in the CISCO-CLASS-BASED-QOS-MIB file. Fortunately, starting from 12.4(4)T, the cbqos keyword has been added to the snmp mib persist global command.

As said, as soon as possibile I’ll post a script to use Cisco CBQoS in Zabbix… stay tuned! 😉

Some useful links: