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Configuring the Probe

The probe statement defines the owner name and test name used as identifiers for the probe. Together, they represent a single RPM configuration instance. When you specify the test name, you also can configure the test parameters.

To configure the probe owner, test name, and test parameters, include the probe statement at the [edit services rpm] hierarchy level:




probe owner {



test test-name {

data-fill data;

data-size size;

destination-interface interface-name;

destination-port port;

dscp-code-point dscp-bits;

hardware-timestamp;

history-size size;

moving-average-size number;

one-way-hardware-timestamp;

probe-count count;

probe-interval seconds;

probe-type type;

routing-instance instance-name;

source-address address;

target (url url | address address);

test-interval interval;

thresholds thresholds;

traps traps;
}


}

To specify a probe owner, include the probe statement at the [edit services rpm] hierarchy level. The probe owner identifier can be up to 32 characters in length.
To specify a test name, include the test statement at the [edit services rpm probe owner] hierarchy level. The test name identifier can be up to 32 characters in length. A test represents the range of probes over which the standard deviation, average, and jitter are calculated.
To specify the contents of the data portion of Internet Control Message Protocol (ICMP) probes, include the data-fill statement at the [edit services rpm probe owner] hierarchy level. The value can be a hexadecimal value. The data-fill statement is not valid with the http-get or http-metadata-get probe types.

To specify the size of the data portion of ICMP probes, include the data-size statement at the [edit services rpm probe owner] hierarchy level. The size can be from 0 through 65507 and the default size is 0. The data-size statement is not valid with the http-get or http-metadata-get probe types.

Note: If you configure the hardware timestamp feature (see Configuring RPM Timestamping), the data-size default value is 32 bytes and 32 is the minimum value for explicit configuration. The UDP timestamp probe type is an exception; it requires a minimum data size of 44 bytes.

To specify the output interface for sending packets to the forwarding plane, include the destination-interface statement at the [edit services rpm probe owner test test-name] hierarchy level. This interface must support looping of probe packets to an input interface without adding any encapsulation by using a pair of logical tunnel interfaces.

Note: This usage of the destination-interface statement is supported only on J-series Services Routers, for which you should specify an lt tunnel interface.

The destination-interface statement is required to support classification of RPM probes generated by JUNOS software that are based on a user-configured classifier. The classified packets are sent to the output queue on the output interface specified by the scheduler map configured on that interface. For more information about classifiers and scheduler maps, see the JUNOS Class of Service Configuration Guide. For a complete configuration example, see Examples: Configuring Real-Time Performance Monitoring.

Caution: Use this feature with caution, because improper configuration can cause packets to be dropped.

On M-series and T-series routing platforms only, you configure the destination-interface statement to enable hardware timestamping of RPM probe packets. You specify an sp- interface to have the AS or MultiServices PIC add the hardware timestamps; for more information, see Configuring RPM Timestamping. On J-series Services Routers, you configure hardware timestamping by including the hardware-timestamp statement. On all platforms, you can also include the one-way-hardware-timestamp statement to enable one-way delay and jitter measurements.
To specify the User Datagram Protocol (UDP) port or Transmission Control Protocol (TCP) port to which the probe is sent, include the destination-port statement at the [edit services rpm probe owner test test-name] hierarchy level. The destination-port statement is used only for the UDP and TCP probe types. The value can be 7 or from 49160 through 65535.
To specify the value of the Differentiated Services (DiffServ) field within the IP header, include the dscp-code-point statement at the [edit services rpm probe owner test test-name] hierarchy level. The DiffServ code point (DSCP) bits value can be set to a valid 6-bit pattern; for example, 001111. It also can be set using an alias configured at the [edit class-of-service code-point-aliases dscp] hierarchy level. The default is 000000.
To specify the number of stored history entries, include the history-size statement at the [edit services rpm probe owner test test-name] hierarchy level. Specify a value from 0 to 255. The default is 50.
To specify a number of samples for making statistical calculations, include the moving-average-size statement at the [edit services rpm probe owner test test-name] hierarchy level. Specify a value from 0 through 255.
To specify the number of probes within a test, include the probe-count statement at the [edit services rpm probe owner test test-name] hierarchy level. Specify a value from 1 through 15.
To specify the time to wait between sending packets, include the probe-interval statement at the [edit services rpm probe owner test test-name] hierarchy level. Specify a value from 1 through 255 seconds.

To specify the packet and protocol contents of the probe, include the probe-type statement at the [edit services rpm probe owner test test-name] hierarchy level. The following probe types are supported:

http-get—Sends a Hypertext Transfer Protocol (HTTP) get request to a target URL.
http-metadata-get—Sends an HTTP get request for metadata to a target URL.
icmp-ping—Sends ICMP echo requests to a target address.
icmp-ping-timestamp—Sends ICMP timestamp requests to a target address.
tcp-ping—Sends TCP packets to a target.
udp-ping—Sends UDP packets to a target.
udp-ping-timestamp—Sends UDP timestamp requests to a target address.

The following probe types support hardware timestamping of probe packets: icmp-ping, icmp-ping-timestamp, udp-ping, udp-ping-timestamp.

Note: Some probe types require additional parameters to be configured. For example, when you specify the tcp-ping or udp-ping option, you must configure the destination port using the destination-port statement. The udp-ping-timestamp option requires a minimum data size of 12; any smaller data size results in a commit error. The minimum data size for TCP probe packets is 1.

To specify the routing instance used by ICMP probes, include the routing-instance statement at the [edit services rpm probe owner test test-name] hierarchy level. The default routing instance is Internet routing table inet.0.
To specify the source IP address used for ICMP probes, include the source-address statement at the [edit services rpm probe owner test test-name] hierarchy level. If the source IP address is not one of the router’s assigned addresses, the packet will use the outgoing interface’s address as its source.
To specify the destination address used for the probes, include the target statement at the [edit services rpm probe owner test test-name] hierarchy level.
- For HTTP probe types, specify a fully formed URL that includes http:// in the URL address.
- For all other probe types, specify an IP version 4 (IPv4) address for the target host.
To specify the time to wait between tests, include the test-interval statement at the [edit services rpm probe owner test test-name] hierarchy level. Specify a value from 0 through 86400 seconds.
To specify thresholds used for the probes, include the thresholds statement at the [edit services rpm probe owner test test-name] hierarchy level. A system log message is generated when the configured threshold is exceeded. Likewise, a Simple Network Management Protocol (SNMP) trap (if configured) is generated when a threshold is exceeded. The following options are supported:
- egress-time—Measures maximum source-to-destination time per probe.
- ingress-time—Measures maximum destination-to-source time per probe.
- jitter-egress—Measures maximum source-to-destination jitter per test.
- jitter-ingress—Measures maximum destination-to-source jitter per test.
- jitter-rtt—Measures maximum jitter per test, from 0 through 60000000 microseconds.
- rtt—Measures maximum round-trip time per probe, in microseconds.
- std-dev-egress—Measures maximum source-to-destination standard deviation per test.
- std-dev-ingress—Measures maximum destination-to-source standard deviation per test.
- std-dev-rtt—Measures maximum standard deviation per test, in microseconds.
- successive-loss—Measures successive probe loss count, indicating probe failure.
- total-loss—Measures total probe loss count indicating test failure, from 0 through 15.
Traps are sent if the configured threshold is met or exceeded. To set the trap bit to generate traps, include the traps statement at the [edit services rpm probe owner test test-name] hierarchy level. The following options are supported:
- egress-jitter-exceeded—Generates traps when the jitter in egress time threshold is met or exceeded.
- egress-std-dev-exceeded—Generates traps when the egress time standard deviation threshold is met or exceeded.
- egress-time-exceeded—Generates traps when the maximum egress time threshold is met or exceeded.
- ingress-jitter-exceeded—Generates traps when the jitter in ingress time threshold is met or exceeded.
- ingress-std-dev-exceeded—Generates traps when the ingress time standard deviation threshold is met or exceeded.
- ingress-time-exceeded—Generates traps when the maximum ingress time threshold is met or exceeded.
- jitter-exceeded—Generates traps when the jitter in round-trip time threshold is met or exceeded.
- probe-failure—Generates traps for successive probe loss thresholds crossed.
- rtt-exceeded—Generates traps when the maximum round-trip time threshold is met or exceeded.
- std-dev-exceeded—Generates traps when the round-trip time standard deviation threshold is met or exceeded.
- test-completion—Generates traps when a test is completed.
- test-failure—Generates traps when the total probe loss threshold is met or exceeded.

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