Contents

Configuring telemetry stream·· 1

About telemetry stream·· 1

How telemetry stream works· 1

Telemetry stream timestamping· 1

Restrictions and guidelines: Telemetry stream configuration· 1

Prerequisites· 1

Configuring basic telemetry stream functions· 1

Configuring telemetry stream timestamping· 2

Verifying and maintaining telemetry stream·· 3

Verifying the configuration and running status for ACLs· 3

Verifying telemetry stream and sampler configuration· 3

Telemetry stream configuration examples· 3

Example: Configuring telemetry stream·· 3

Configuring telemetry stream

About telemetry stream

Telemetry stream is a network monitoring technology used to collect data from devices. It continuously streams data to a collector.

Telemetry stream supports collecting the input interface, output interface and timestamp of traffic.

How telemetry stream works

Telemetry stream works as follows:

1.     Telemetry stream samples a matching packet on the input interface and copies it to the telemetry stream processor in the device. The telemetry stream processor adds the input interface information to the packet.

2.     The telemetry stream processor encapsulates the packet and routes it to the collector.

The collector can calculate the path and delay information according to the collected data from multiple nodes.

Telemetry stream timestamping

With this function enabled, the device carries the timestamp in its packets sent to the collector. The collector can calculate the delay introduced when a node forwards packets. Additionally, the collector can use the timestamp information collected from multiple nodes to calculate the delay introduced when packets are forwarded along the path.

Restrictions and guidelines: Telemetry stream configuration

The collected data is encapsulated in sFlow packets. The sFlow packet does not include the Extended Switch Data or Extended Router Data field, and the value of the sample pool field is fixed.

Prerequisites

Configure routing to make sure the devices can reach each other.

Configuring basic telemetry stream functions

About this task

The device samples a matching packet on the input interface and copies it to the telemetry stream processor in the device. The telemetry stream processor adds the input and output interface information to the packet, encapsulates it, and routes it to the collector.

Too many original packets will overwhelm the Telemetry processor and even cause it to drop packets. To address this problem, you can use an ACL or sampler on the input interface to reduce the packets sent to the collector. Only packets matching a permit ACL rule or sampled packets are sent to the collector.

If the data portion of original packets is large, you can enable the truncation function to save the link bandwidth consumed between the device and the collector and reduce the parsing load of the collector. The truncation function truncates the packets before sending them to the collector. The truncated packets retain complete input interface, output interface, and timestamp information.

Procedure

1.     Specify a device ID.

a.     Enter system view.

system-view

b.     Specify a device ID.

telemetry stream device-id address

By default, no device ID is specified.

2.     Configure addressing parameters to encapsulate in the packets sent to the collector.

telemetry stream collector source source-address destination destination-address source-port source-port destination-port destination-port [ vpn-instance vpn-instance-name ] [ truncation ]

By default, no addressing parameters are configured.

As a best practice, specify the truncation keyword when you execute this command. If you do not specify the truncation keyword, telemetry stream might fail to collect data about packets when the packet length approaches the interface MTU.

3.     Configure a telemetry stream action on the input interface.

a.     Enter interface view.

interface interface-type interface-number

b.     Configure a telemetry stream action on the interface.

telemetry stream action action-id [ acl [ ipv6 | mac | user-defined ]  { acl-number | name acl-name } | sampler sampler-name ] *

By default, no telemetry stream action is configured.

To collect data about MPLS packets, you must specify a Layer 2 ACL that matches packets with the link layer protocol as 8847.

c.     Return to system view.

quit

For information about ACLs, see ACL and QoS Configuration Guide.

For information about samplers, see Network Management and Monitoring Configuration Guide.

4.     Enable telemetry stream.

telemetry stream enable

By default, telemetry stream is enabled.

Configuring telemetry stream timestamping

About this task

This feature allows the device to add the timestamp information when a packet enters and leaves it.

Procedure

Enable telemetry stream timestamping.

telemetry stream timestamp enable

By default, telemetry stream timestamping is disabled.

Verifying and maintaining telemetry stream

Verifying the configuration and running status for ACLs

To verify the ACL configuration and running status, perform the following command in any view:

display acl [ ipv6 | mac | user-defined ] { acl-number | all | name acl-name }

For more information about this command, see ACL and QoS Command Reference.

Verifying telemetry stream and sampler configuration

Perform display tasks in any view.

·     Display sampler configuration.

For more information about the display sampler command, see Network Management and Monitoring Command Reference.

·     Display telemetry stream r configuration.

display telemetry stream

Telemetry stream configuration examples

Example: Configuring telemetry stream

Network configuration

As shown in Figure 1, configure telemetry stream on Device B for the collector to calculate the delay when packets are forwarded by Device B.

Figure 1 Network diagram

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Prerequisites

IMPORTANT: By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

 

Assign IP addresses to interfaces and configure routing protocols. (Details not shown.)

Procedure

# Specify 10.0.0.1 as the device ID.

<DeviceB> system-view

[DeviceB] telemetry stream device-id 10.0.0.1

# Configure addressing parameters to encapsulate in telemetry stream packets sent to the collector.

[DeviceB] telemetry stream collector source 20.0.0.2 destination 30.0.0.1 source-port 12 destination-port 14

# Enable telemetry stream timestamping.

[DeviceB] telemetry stream timestamp enable

# Create sampler samp in random sampling mode, and set the sampling rate to 8. One packet from 256 (2 to the 8th power) packets is selected.

[DeviceB] sampler samp mode random packet-interval n-power 8

# Create IPv4 basic ACL 2000, and configure a rule to match packets with source IP address 192.168.1.2.

[DeviceB] acl basic 2000

[DeviceB-acl-ipv4-basic-2000] rule permit source 192.168.1.2 0

[DeviceB-acl-ipv4-basic-2000] quit

# Configure telemetry stream action 1 to use ACL 2000 and sampler samp on HundredGigE 1/0/1.

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] telemetry stream action 1 acl 2000 sampler samp

[DeviceB-HundredGigE1/0/1] quit

# Enable telemetry stream.

[DeviceB] telemetry stream enable

Verifying the configuration

# Display the telemetry stream configuration on Device B.

[DeviceB] display telemetry stream

  Telemetry stream status          : Enabled

  Telemetry stream timestamp status: Enabled

  Telemetry stream device-id       : 10.0.0.1

  Telemetry stream action:

    HundredGigE1/0/1:

      Telemetry stream action 1:

        ACL    : 2000

        Sampler: samp

  Telemetry stream collector:

    Source IP       : 20.0.0.2

    Destination IP  : 30.0.0.1

    Source port     : 12

    Destination port: 14