Usage Scenario

To obtain more flow statistics, you can configure the flexible flow statistics to be sent to the NSC to contain the application name.

Prerequisites

A flexible flow statistics template has been created before the collect application command is run.

Precautions

If a flexible flow statistics template has been applied to an interface, the template configuration cannot be modified or deleted.

Usage Scenario

To obtain richer flow statistics, configure whether flexible flow statistics contain the number of bytes and packets.

Prerequisites

A flexible flow statistics template has been created.

Precautions

If a flexible flow statistics template has been applied to an interface, the template configuration cannot be modified or deleted.

Usage Scenario

To obtain richer flow statistics, configure whether flexible flow statistics exported to the NSC contain indexes of inbound and outbound interfaces.

Prerequisites

A flexible flow statistics template has been created.

Precautions

If a flexible flow statistics template has been applied to an interface, the template configuration cannot be modified or deleted.

Usage Scenario

To obtain more flow statistics in SD-WAN scenarios, you can run this command to configure the flexible flow statistics output to contain the source TNP, destination TNP, source site ID, and destination site ID.

Prerequisites

Before running the collect sd-wan connection command, you must create a flexible flow statistics template.

Precautions

If a flexible flow statistics template has been applied to an interface, the template configuration cannot be modified or deleted.

Usage Scenario

Multiple flexible flows can be configured, each of which can be assigned matching and collected fields. To help rapidly understand a flexible flow, run the description command to configure a description for each flow. For example, a description defines some fields or meanings of fields in packets for a flexible flow.

Configuration Impact

If a description has been configured for a flexible flow, running the description command override the previous description.

Displays the NetStream configuration.

Usage Scenario

This command displays real-time statistics on IPv4 original flows on the device.

Precautions

This command must be executed before the flows age out; otherwise, no information will be displayed.

Usage Scenario

This command displays real-time statistics on IPv4 flexible flows on the device.

Precautions

This command must be executed before the flows age out; otherwise, no information will be displayed.

Usage Scenario

You can run this command to query IPv4 flow statistics on a device, including the statistics clearance time, statistics on packets of different lengths, traffic statistics collection method, and statistics on different types of flows.

Usage Scenario

During NetStream implementation, you can run the match ip command to configure aggregation keywords in a flexible flow statistics template.

Prerequisites

The netstream record ip (system view) command has been executed to create an IPv4 flexible flow statistics template.

Precautions

When you run the match ip command to configure the aggregation keywords, only one keyword can be configured each time. If you run this command multiple times in the same view, a set of multiple aggregation keywords is configured. If a template has been applied to an interface, you cannot modify or delete aggregation keywords from the template.

Usage Scenario

After finishing data collection, the NDE sends the collected data to the NSC. This command specifies the destination address of the collected data, that is, the NSC IP address.

Precautions

Two groups of destination IP addresses and destination port numbers can be configured for IPv4 flow statistics collection to implement NSC backup. Before configuring the third group of destination IP addresses and destination port numbers, run the undo netstream export ip host command to delete the original group. Otherwise, the system will display a message indicating that the maximum numbers of IP addresses and port numbers have been reached and the configuration will fail.

Usage Scenario

You can run this command to set the number of digits in an interface index to 16 or 32.

The number of digits in the interface index is set according to the type of the interface index that can be parsed by the NMS. For example, if the NMS can parse 32-bit interface indexes, set the format of the interface indexes contained in exported NetStream packets to 32-bit.

Precautions

The interface index length in exported packets can be set to 32 bits only when the NMS supports 32-bit interface index; otherwise, the NMS cannot identify the NetStream packets.

This command takes effect for only V9 exported packets.

When the export version for IPv4 original flow statistics and IPv4 flexible flow statistics is set to V9, the template must be exported to the NDA. This command sets the interval for refreshing the V9 template.

If network traffic is heavy, the template refresh interval should be set to a small value; however, this will generate more traffic on the network. You need to set a proper template refresh interval according to network situation. The default refresh interval is recommended if you do not have special requirement.

Usage Scenario

Precautions

When the exported packets carry 32-bit interface indexes, the export version cannot be changed from V9 to V5.

Usage Scenario

If the NMS needs to identify the data source according to the source IP address in NetStream packets, specify the source IP address for NetStream packets.

Precautions

If the source IP address is not specified, packets are not exported. The source IP address of the exported packets carrying IPv4 flow statistics can be an IPv4 address. There must be a reachable route between the source IP address and destination IP address (NSC address). The same source IPv4 address can be configured for different types of exported packets carrying flow statistics.

Usage Scenario

To export IPv4 flow statistics, you must run the netstream ip command to enable the IPv4 flow statistics collection function on the interface.

You can run the netstream ip and netstream ipv6 commands on an interface to collect statistics about IPv4 and IPv6 flows, respectively. There is no interference between the two commands.

Prerequisites

Before running the netstream ip command on an interface, you need to run the netstream sampler command on the interface.

Precautions

Usage Scenario

After a flexible flow statistics template is configured, run the command to apply the template to an interface.

The interface then aggregates flows based on the configured aggregation keywords, collects flow statistics, and exports aged flows to the NSC.

Prerequisites

Before an IPv4 flexible flow statistics template is applied to an interface, the template must contain at least one aggregation keyword; otherwise, the template cannot be applied to an interface. The keyword is configured using the match ip command.

Precautions

Usage Scenario

You need to create the IPv4 flexible flow statistics template before exporting flexible flow statistics.

Precautions

A maximum of 16 flexible flow statistics templates can be configured on one device. To configure a new flexible flow statistics template, run the undo ip netstream record command to delete an existing one first.

The flexible flow statistics template that has been applied to an interface cannot be modified or deleted. To delete this flexible flow statistics template, run the undo netstream record ip command on the interface and then modify or delete the template.

Usage Scenario

After the NetStream function is enabled on an interface, the system stores the NetStream information in the corresponded interface information table. If every packet passing an interface is captured and counted, forwarding performance on the interface will deteriorate, especially on the interface with a high forwarding rate. To understand interface traffic attributes without compromising forwarding performance, configure packet sampling on the interface. A low sampling rate can significantly reduce impact of NetStream on device performance.

Precautions

Usage Scenario

Network traffic may burst intermittently, while the memory capacity of the NDE is limited. Earlier flows in the memory need to be exported to release space for the new flows. The process of exporting old flows is called aging. All flows in the NDE memory will be exported to the NSC for analysis.

When the active time (from flow creation time to the current time) of an original or flexible flow exceeds the specified active aging time, the flow is exported to the destination.

To quickly detect the status of an active flow, set the active time to a small value; however, this setting increases the frequency at which NetStream packets are sent. To reduce the frequency at which NetStream packets are exported and improve statistics collecting efficiency, set the active time to a large value.

Precautions

If you set multiple aging modes on the device, a flow is aged when it matches any criterion.

Usage Scenario

Network traffic may burst intermittently, while the memory capacity of the NDE is limited. Earlier flows in the memory need to be exported to release space for the new flows. The process of exporting old flows is called aging. All flows in the NDE memory will be exported to the NSC for analysis.

When the inactive time (from the last packet receiving time to the current time) of an original or flexible flow exceeds the specified inactive aging time, the flow is exported to the destination.

To quickly detect the status of an inactive flow, set the inactive time to a small value; however, this setting increases the frequency at which NetStream packets are sent. To reduce the frequency at which NetStream packets are exported and improve statistics collecting efficiency, set the inactive time to a large value.

Precautions

If you set multiple aging modes on the device, a flow is aged when it matches any criterion.

Usage Scenario

The FIN or RST flag in a TCP packet indicates that the TCP connection is terminated. When receiving a packet with the FIN or RST flag, the device immediately ages the corresponding NetStream flow. If this command is not run, NetStream flows are aged by following other criteria, for example, inactive aging time or bytes overflow.

Precautions

If you set multiple aging modes on the device, a flow is aged when it matches any criterion.

Only original flows can be aged according to the FIN or RST flag in the TCP packet header.

Usage Scenario

By default, queue scheduling is performed after NetStream sampling. If the sampled packets include packets discarded by the local device, the bandwidth calculated based on the sampled data is greater than the bandwidth configured on the interface. To solve this problem, run the netstream tm-after enable command to enable NetStream sampling after queue scheduling.

Precautions

The netstream tm-after enable command takes effect only after the traffic tm-post-processing enable command is run on the corresponding interface.

You can run this command to forcibly age out packets on the device.

Usage Scenario

When diagnosing and locating network faults, collect flow statistics in a specified period. Before statistics collection starts, you can run this command to delete historical flow statistics.

Precautions

The reset netstream statistics ethernet command deletes all flow statistics. The statistics cannot be restored after being deleted. Before running this command, confirm the action.

You can run this command multiple times at any interval.