Q. What is CiscoWorks Internetwork Performance Monitor (IPM)?
A. CiscoWorks IPM is a component of the CiscoWorks LAN Management Solution (LMS), which is an integrated suite of applications for administering, monitoring, and troubleshooting Cisco® networks. CiscoWorks IPM is a network-performance troubleshooting tool that empowers network engineers to proactively troubleshoot network-performance problems. CiscoWorks IPM measures network performance based on the following metrics: latency, jitter, availability, packet loss, and errors. CiscoWorks IPM can report on these metrics using either real-time or historical reports, or it can define performance thresholds that will automatically provide notification if they are violated.
Q. What is new in CiscoWorks IPM 2.6?
A. CiscoWorks IPM 2.6 includes the following new features and improvements:
• Improved user interface consistency with other CiscoWorks applications
– Device Import
– Device Center
– Eliminated separate Web server
– Cisco Secure Access Control Server (ACS)-based user roles for security
• Support for Differentiated Services Code Point (DSCP)
• Ability to specify source-port address
• Improved scalability (2000 collectors)
• Optional Secure Sockets Layer (SSL) between client and server
Q. Can CiscoWorks IPM be used to troubleshoot quality of service (QoS) performance in a network?
A. Yes. CiscoWorks IPM collectors can be configured to include an IP Precedence and DSCP values. The synthetic traffic generated by the Cisco IOS® IP SLA feature in the source device based on such a configuration will provide a performance measurement for the specified value of IP Precedence. As a result, between any two points in a network, CiscoWorks IPM can measure performance for various traffic classes as defined by the IP Precedence or DSCP values assigned to each traffic class.
Q. Can CiscoWorks IPM be used to troubleshoot voice over IP (VoIP) in a data network?
A. Yes. With the new enhanced User Datagram Protocol (UDP) jitter operations supported by CiscoWorks IPM, it is possible to perform monitoring and troubleshooting of the network's ability to carry IP-based telephony.
Q. In using CiscoWorks IPM, what is meant by the following terms: source, target, operation, and collector?
A. Definitions are as follows:
• "Source" is a device that supports the Cisco IOS Software IP SLA technology and plays a critical role in network-performance measurement. The source device actually generates synthetic network traffic to a destination, and measures the latency, jitter, packet loss, and errors from the destination. These metrics are stored in source-device memory as performance data, which is collected by CiscoWorks IPM on an hourly basis.
• "Target" is the destination device receiving synthetic network traffic from the source device. The target provides a response to the synthetic traffic sent to it by the source device.
• "Operation" is a set of parameters that define the type of synthetic traffic generated by the source router. These parameters include network-protocol type, packet-priority value, packet size, and measurement interval.
• "Collector" is the combination of source, target, and operation that is configured by the user to help enable CiscoWorks IPM to provide network-performance measurements.
Q. What network protocols do the CiscoWorks IPM collectors simulate?
A. CiscoWorks IPM provides support for the following types of operations:
• Domain Name System (DNS) Echo
• DLSw Echo
• Dynamic Host Control Protocol (DHCP) Echo
• Enhanced UDP
• Internet Control Message Protocol (ICMP) Echo
• ICMP Path Echo
• Systems Network Architecture (SNA) Echo
• TCP Connect
• File Transfer Protocol (FTP)
• UDP Echo
• HTTP (static URLs)
• Support for Loose Source Routing and QoS (IP Precedence and DSCP)]
Q. Does CiscoWorks IPM require a network-management system such as HP OpenView, or CA Unicenter?
A. CiscoWorks IPM has no dependencies on these network-management platforms. However, if you use CiscoWorks IPM to configure Simple Network Management Protocol (SNMP) performance thresholds in the source router, then you should have a network management system (NMS) set up to receive and view the SNMP traps transmitted by the source when a performance threshold has been exceeded. Either HP OpenView or CA Unicenter can play a valuable role as a fault monitor in conjunction with CiscoWorks IPM. CiscoWorks IPM itself does not receive these SNMP traps.
Q. Does CiscoWorks IPM require a dedicated hardware probe to monitor response time and availability?
A. No. CiscoWorks IPM uses the IP SLA software feature embedded within the Cisco IOS Software to measure response time and availability.
Q. Does CiscoWorks IPM measure response time from the point of view of the management workstation?
A. No. CiscoWorks IPM configures the Cisco IOS IP SLA feature of Cisco IOS Software to take network-performance measurements from source. As such, these measurements are taken from the perspective of devices within the network rather than from the perspective of the CiscoWorks IPM management workstation, and thereby provide a more valuable perspective of network performance.
Q. Do I have to install any software on the router to use IP SLA and CiscoWorks IPM?
A. The IP SLA is embedded in many but not all feature sets of Cisco IOS Software. A release of Cisco IOS Software that supports IP SLA must be installed on the source device used by CiscoWorks IPM to measure response time. Table 1 summarizes which Cisco IOS Software releases support IP SLA.
Table 1. Cisco IOS Software Support
Cisco IOS Software Release
Cisco IOS Feature Set
IPM and IP SLA Support
Maximum Duration for Collectors
Earlier than Cisco IOS Software Release 11.2(8)
All
No
-
Cisco IOS Software Release 11.2(8) to 11.2(15)
IP Plus
Desktop Plus
IBM
Enterprise
Yes
23 days
IP only
IP and IPX
Desktop
No
-
Cisco IOS Software Release 11.2(16) to 11.2(x) (x later than 16)
IP Plus
Desktop Plus
IBM
Enterprise
Yes
Forever
IP only
IP and IPX
Desktop
No
-
All
No
-
Cisco IOS Software Release 11.3(6) to 11.3(y) (y later than 6)
Q. How many collectors (monitored network links) can be configured on each router platform?
A. The IP SLA restricts the number of configured collectors to a maximum of 200 per router for Cisco IOS Software releases 11.2 and 11.3, 500 collectors per router for Cisco IOS Software releases 12.0(5) to 12.1(1), and 500 collectors per router for Cisco IOS Software releases 12.0(5)T to 12.1(2)T. The Cisco IOS Software releases 12.2(1) and 12.2(1)T or later do not have fixed collector limitations. The actual number of supported collectors, however, depends on the specific source platform and amount of RAM installed in the router. To know how many collectors can be configured, run the following commands at source.
Step 1. Log in to the router.
Step 2. Run the "show rtr application" command at the router prompt. You should be able to see the output similar to the following.
Router-prompt>show rtr application
Response Time Reporter
Version: 2.2.0 Round Trip Time MIB
Max Packet Data Size (ARR and Data): 16384
Time of Last Change in Whole RTR: *22:08:08.000 UTC Sun Apr 18 1993
System Max Number of Entries: 500 <=
.....................
.....................
Protocol Type: jitterAppl
Protocol Type: dhcp
Protocol Type: ftpAppl
Number of configurable probe is 366 <=
Output shows the maximum number collectors allowed and current configurable limit.
Q. How do I verify that IP SLA agent is supported on a device running Cisco IOS Software?
A. You can verify with the following commands.
Step 1. Log in to the router.
Step 2. Step 2: Run the "show rtr application" command at the router prompt. You should be able to see the output similar to the following.
Router-prompt>show rtr application
Response Time Reporter
Version: 2.2.0 Round Trip Time MIB
Max Packet Data Size (ARR and Data): 16384
Time of Last Change in Whole RTR: *22:08:08.000 UTC Sun Apr 18 1993
System Max Number of Entries: 500
Number of Entries configured: 134
Number of active Entries: 134
Number of pending Entries: 0
Number of inactive Entries: 0
Supported Operation Types
Type of Operation to Perform: echo
Type of Operation to Perform: pathEcho
Type of Operation to Perform: udpEcho
Type of Operation to Perform: tcpConnect
Type of Operation to Perform: http
Type of Operation to Perform: dns
Type of Operation to Perform: jitter
Type of Operation to Perform: dlsw
Type of Operation to Perform: dhcp
Type of Operation to Perform: ftp
Supported Protocols
Protocol Type: ipIcmpEcho
Protocol Type: ipUdpEchoAppl
Protocol Type: ipTcpConn
Protocol Type: httpAppl
Protocol Type: dnsAppl
Protocol Type: jitterAppl
Protocol Type: dhcp
Protocol Type: ftpAppl
Number of configurable probe is 366
Q. How does CiscoWorks IPM interact with the IP SLA feature of Cisco IOS Software?
A. CiscoWorks IPM uses SNMP to configure IP SLA in the Cisco IOS Software of a source to collect response time and availability statistics. The IP SLA samples response time and availability to targets (network devices, servers, PCs, and so on) in the network. CiscoWorks IPM then uses SNMP to collect performance statistics from the SA Agent, and stores that information for presentation and analysis.
Q. What is the name of the MIB used by CiscoWorks IPM?
A. CiscoWorks IPM both configures and queries the RTTMON MIB, which is supported by the IP SLA feature in Cisco IOS Software. Also CiscoWorks IPM queries the CISCO-IMAGE_MIB, MIB-II IP, CISCO-MEMORY-POOL-MIB, MIB-II System MIBs. This MIB may be downloaded from the Cisco.com.
Q. Do I have to be running a Cisco IOS Software Release 11.2 or later with the IP SLA feature on all my routers between source and target to get hop-by-hop performance statistics?
A. No. You are required to be running the IP SLA feature only on the source device in the path being measured.
Q. Should I install the IP SLA on a backbone router so that it intercepts all paths?
A. The answer ultimately depends on the number of IP SLA collectors you will be monitoring at any one time. IP SLA uses memory and CPU cycles, so Cisco Systems® recommends that you run the IP SLA on multiple fringe routers instead. This setup distributes the load across multiple routers.
Q. How does CiscoWorks IPM measure response time between routers in the Systems Network Architecture (SNA) environment?
A. In the SNA environment, CiscoWorks IPM uses an "SNA ping." CiscoWorks IPM ships with a component that runs on the mainframe. The router component of CiscoWorks IPM sends a block of data (the request) to the mainframe component, which responds with a block of data (the response). Both the request and response sizes can be customized by the user so that traffic flow for various applications can be modeled. CiscoWorks IPM supports the SNA ping over logical unit (LU) 0 and LU 2 sessions.
Q. How much of the router's memory do collectors in IP SLA consume?
A. Table 2 shows the router memory consumed by some of the operations. IP SLA Engine 1 (prior to Cisco IOS Software Release 12.2(11)T) and Engine 2 have different memory requirements. Engine 2 takes less memory compared to Engine 1.
Table 2. Router Memory Consumption
Engine 1
Engine 2
UDP Jitter
< 24 KB
< 12 KB
UDP Echo
< 19 KB
< 3.5 KB
ICMP Echo
< 17 KB
< 3.2 KB
The router memory consumed by a Path Echo collector depends on the number of paths and the number of hops in the path for each collector.
For all other operations, memory requirements are more or less same as ICMP Echo.
Q. How frequently can network-performance measurements be taken?
A. IP SLA generates several measurements per hour, then CiscoWorks IPM polls the router once per hour and collects summarized statistics for that 1-hour period. This 1-hour frequency is not user-configurable. You can set the sampling interval for IP SLA as often as every 10 seconds, but for optimal performance, Cisco recommends that you set the sample interval to at least 60 seconds (1 minute). This is the default value.
You can view up-to-date statistics in the real-time statistics window as IP SLA collects the data from the collector. However, CiscoWorks IPM does not store the real-time data in the IPM database. CiscoWorks IPM only stores the hourly-summarized data in the IPM database.
Q. When CiscoWorks IPM collects the data from the IP SLA using SNMP, is this data averaged or summarized in any way?
A. The data is summarized and averaged in a variety of ways. CiscoWorks IPM displays the data in the historical statistics window in hourly, daily, weekly, and monthly increments. CiscoWorks IPM also displays average, minimum, and maximum calculations of the data over the monitoring period. In addition, it provides an automatic aging facility for summarizing and aging older data.
Q. How many data collectors can CiscoWorks IPM support?
A. There is no functional limit on the number of collectors that CiscoWorks IPM can support. However, it is recommended that you limit the maximum number of collectors per CiscoWorks IPM server to 2000. To support more than 2000 collectors, you can deploy multiple CiscoWorks IPM servers. Many users deploy a CiscoWorks IPM server in each geographic area of their network.
FOR MORE INFORMATION
For more information about the CiscoWorks Internetwork Performance Monitor and CiscoWorks LAN Management Solution, visit http://www.cisco.com/go/lms or contact your local Cisco account representative or send an e-mail to the Product Marketing group at ciscoworks@cisco.com.
