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Inline Monitoring Services Configuration

Understanding Inline Monitoring Services

Benefits of Inline Monitoring Services

Flexible—Inline monitoring services allow different inline-monitoring instances to be mapped to different firewall filter terms, unlike in traditional sampling technologies, where all the instances are mapped to the Flexible PIC Concentrator (FPC). This provides you with the flexibility of sampling different streams of traffic at different rates on a single interface.

Packet format agnostic—Traditional flow collection technologies rely on packet parsing and aggregation by the network element. With inline monitoring services, the packet header is exported to the collector for further processing, but without aggregation. Thereby, you have the benefit of using arbitrary packet fields to process the monitored packets at the collector.

Inline Monitoring Services Feature Overview

Service providers and content providers typically require visibility into traffic flows to evaluate peering agreements, detect traffic anomalies and policy violations, and monitor network performance. To meet these requirements, you would traditionally export aggregate flow statistics information using JFlow or IPFIX variants.

As an alternative approach, you can sample the packet content, add metadata information, and export the monitored packets to an collector. The inline monitoring services enable you to do this on MX Series routers and on PTX routers that run Junos OS Evolved.

With inline monitoring services, you can monitor every IPv4 and IPv6 packet on both ingress and egress directions of an interface. The software encapsulates the monitored traffic in an IPFIX format and exports the actual packet up to the configured clip length to an collector for further processing. By default, Junos OS supports a maximum clip length of 126 bytes starting from the Ethernet header and Junos OS Evolved supports a maximum clip length of 256 bytes starting from the Ethernet header.

Figure 1 illustrates the IPFIX format specification.

Figure 1: Inline Monitoring IPFIX SpecificationInline Monitoring IPFIX Specification

The IPFIX header and IPFIX payload are encapsulated using IP or UDP transport layer. The exported IPFIX format includes two data records and two data templates that are exported to every collector:

  • Data record—Includes incoming and outgoing interface, flow direction, data link frame section, and data link frame size. This information is sent to the collector only when sampled packets are being exported.

    Figure 2 is a sample illustration of IPFIX data record packet.

  • Option data record—Includes system level information, such as exporting process ID, and sampling interval. This information is sent to the collector periodically, irrespective of whether sampling packets are being exported are not.

    Figure 3 is a sample illustration of IPFIX option data record packet.

    Table 1: Information Element fields in IPFIX Option Data Packet

    Number

    Information Element ID

    Information Element Length

    Details

    1

    144

    4B

    Observation domain ID - An unique identifier of exporting process per IPFIX device. Purpose of this field is to limit the scope of other information element fields.

    2

    34

    4B

    Sampling interval at which the packets are sampled. 1000 indicates that one of 1000 packets is sampled.

  • Data template—Includes five information elements:

    • Ingress interface

    • Egress interface

    • Flow direction

    • Data link frame size

    • Variable data link frame selection

    Figure 4 is a sample illustration of IPFIX data template packet.

  • Option data template—Includes flow exporter and sampling interval information.

    Figure 5 is a sample illustration of IPFIX option data template packet.

When there is a new or changed inline monitoring services configuration, periodic export of data template and option data template is immediately sent to the respective collectors.

Figure 2: IPFIX Data RecordIPFIX Data Record
Figure 3: IPFIX Option Data RecordIPFIX Option Data Record
Figure 4: IPFIX Data TemplateIPFIX Data Template
Figure 5: IPFIX Option Data TemplateIPFIX Option Data Template

Inline Monitoring Services Configuration Overview

You can configure a maximum of sixteen (Junos OS) or seven (Junos OS Evolved) inline-monitoring instances that support template and collector-specific configuration parameters. Each inline monitoring instance supports up to four collectors (maximum of 64 collectors in total), and, for Junos OS only, you can specify different sampling rates under each collector configuration. Because of this flexibility, the inline monitoring services overcome the limitations of traditional sampling technologies, such as JFlow, sFlow, and port mirroring.

To configure inline monitoring:

  1. You must include the inline-monitoring statement at the [edit services] hierarchy level. Here you specify the template and inline monitoring instance parameters. You must specify the collector parameters under the inline-monitoring instance.

  2. Specify arbitrary match conditions using a firewall filter term and an action to accept the configured inline-monitoring instance. This maps the inline-monitoring instance to the firewall term.

  3. Map the firewall filter under the family inet or inet6 statement using the inline-monitoring-instance statement at the [edit firewall filter name then] hierarchy level. Starting in Junos OS Release 21.1R1, you can also map the firewall filter under the family any, bridge, ccc, mpls, or vpls statements. For Junos OS Evolved, the bridge and vplsfamilies are not supported; use the ethernet-switch family instead. Junos OS Evolved does support the any, ccc, inet, inet6, and mpls families as well. You can also alternatively apply the firewall filter to a forwarding table filter with input or output statement to filter ingress or egress packets, respectively.

Remember:

  • The device must support a maximum packet length (clip length) of 126 bytes (Junos OS) or 256 bytes (Junos OS Evolved) to enable inline monitoring services.

  • You cannot configure more than 16 (Junos OS) or 7 (Junos OS Evolved) inline-monitoring instances because of the scarcity of bits available in the packet in the forwarding path.

  • Apply inline monitoring services only on a collector interface, that is, the interface on which the collector is reachable. You must not apply inline monitoring on IPFIX traffic as this generates another IPFIX packet for sampling, thereby creating a loop. This includes inline monitoring service-generated traffic, such as template and record packets, option templates, and option record packets.

  • When inline monitoring service is enabled on aggregated Ethernet (AE) interfaces, the information element values are as follows:

    Table 2: Information Element Values for Aggregated Ethernet Interfaces

    Direction of inline monitoring service on AE interface

    Information element-10 (Incoming interface)

    Information element-14 (Outgoing interface)

    Ingress

    SNMP ID of AE

    0

    Egress

    SNMP ID of AE

    SNMP ID of member link

  • When inline monitoring service is enabled on IRB interfaces, the information element values are as follows:

    Table 3: Information Element Values for IRB Interfaces

    Direction of inline monitoring service on IRB interface

    Information element-10 (Incoming interface)

    Information element-14 (Outgoing interface)

    Ingress

    SNMP ID of IRB

    0

    Egress

    SNMP ID of IRB

    SNMP ID of vlan-bridge encapsulated interface

  • For XL-XM based devices (with Lookup chip (XL) and buffering ASIC (XM)), the length of the Data Link Frame Section information element in an exported packet can be shorter than the clip length even if the egress packet length is greater than clip length.

    The length of the Data Link Frame Section information element is reduced by 'N' number of bytes where 'N' = (ingress packet Layer 2 encapsulation length - egress packet Layer 2 encapsulation length).

    For instance, the Layer 2 encapsulation length for the ingress packet is greater than that of the egress packet when the ingress packet has MPLS labels and egress packet is of IPv4 or IPv6 type. When traffic flows from the provider edge (PE) device to the customer edge (CE) device, the ingress packet has VLAN tags and the egress packet is untagged.

    In such cases, the clip length can go past the last address location of the packet head, generating a PKT_HEAD_SIZE system log message. This can result in degradation of packet forwarding for the device.

  • In case of inline monitoring services in the ingress direction, the egressInterface (information element ID 14) does not report SNMP index of the output interface. This information element ID always reports value zero in case of ingress direction. The receiving collector process should identify the validity of this field based on the flowDirection (information element ID 61).

Supported and Unsupported Features with Inline Monitoring Services

Inline monitoring services supports:

  • Graceful Routing Engine switchover

  • In-service software upgrade (ISSU), nonstop software upgrade (NSSU), and nonstop active routing (NSR)

  • Ethernet interfaces and integrated routing and bridging (IRB) interfaces

  • Junos node slicing

Inline monitoring services currently does not support:

  • Configuring more than 16 (Junos OS) or 7 (Junos OS Evolved) inline-monitoring instances.

  • Junos Traffic Vision

  • Prior to Junos OS Release 21.1R1, the inline-monitoring-instance term action is supported only for inet and inet6 family firewall filters. Starting in Junos OS Release 21.1R1, it is supported for the any, bridge, ccc, mpls, and vpls family firewall filters.

  • IPv6 addressable collectors

  • Virtual platforms

  • Logical systems

  • Configuring both the observation domain ID and observation cloud ID. You must choose only one of them.
  • An inline monitoring instance action used for exception reporting cannot be used for any other purpose, such as a firewall re-direct action or a regular inline-monitoring action.
  • An inline monitoring instance used for a firewall re-direct action cannot be used for any other purpose, such as exception reporting or a regular inline-monitoring action.
  • Configuring DSCP, forwarding class, or routing instances for collectors (Junos OS Evolved).
  • Configuring template IDs or option template IDs (Junos OS Evolved). The system generates these for you.
  • Configuring port mirroring and inline monitoring services under the same firewall filter term (Junos OS Evolved).
  • In the egress direction, configuring both SFlow and exception reporting; you must choose only one of them (Junos OS Evolved).

Configuring Inline Monitoring Services

The inline monitoring services can monitor both IPv4 and IPv6 traffic on both ingress and egress directions. You can enable inline monitoring on MX Series routers with MPCs (Junos OS) and on PTX routers that run Junos OS Evolved.

SUMMARY You can configure inline monitoring services to monitor different streams of traffic at different sampling rates on the same logical unit of the interface. You can also export the original packet size to an collector along with information on the interface origin for effective troubleshooting.

Before You Configure

When you configure inline monitoring services, you can:

  • Configure up to 16 (Junos OS) or 7 (Junos OS Evolved) inline-monitoring instances. Under each instance, you can configure specific collector and template parameters.

  • Configure up to 4 IPv4-addressable collectors under each inline-monitoring instance. In total, you can configure up to 64 collectors. The collectors can be remote, and at different locations.

    For each collector, you can configure specific parameters, such as source and destination address, and so on. The default routing-instance name at the collector is default.inet.

  • For Junos OS, you can configure the inet or inet6 family firewall filter with the term action inline-monitoring-instance inline-monitoring-instance-name. Starting in Junos OS Release 21.1R1, you can configure any, bridge, ccc, mpls,or vpls family firewall filters with the term action inline-monitoring-instance inline-monitoring-instance-name. For Junos OS Evolved, you can configure the any, ccc, ethernet-switch, inet, inet6, or mpls family firewall filters with the term action inline-monitoring-instance inline-monitoring-instance-name.

    Each term can support a different inline-monitoring instance.

  • Attach the inline monitoring firewall filter under the family of the logical unit of the interface.

After successfully committing the configuration, you can verify the implementation of the inline monitoring services by issuing the show services inline-monitoring statistics fpc-slot command from the CLI.

Note:

If a packet requires inline monitoring services to be applied along with any of the traditional sampling technologies (such as JFlow or SFlow), the Packet Forwarding Engine performs both inline monitoring services and the traditional sampling technology on that packet. Port mirroring currently must be configured under a different term for Junos OS Evolved.

Figure 6 is a sample illustration of inline monitoring services, where traffic is monitored at two different sampling rates on the device interface, and exported to four remote collectors in an IPFIX encapsulation format. For Junos OS, you configure the sampling rate on each collector, allowing different rates for each collector. For Junos OS Evolved, you configure the sampling rate on the inline-monitoring instance, and it applies to all of the collectors configured for that instance.

Figure 6: Inline Monitoring Services Inline Monitoring Services

In this example, the et-1/0/0 interface of the device is configured with inline monitoring services. The details of the configurations are as follows:

  • There are two inline-monitoring instances — Instance 1 and Instance 2.

  • There are four collectors, two collectors under each inline monitoring instance.

    • Instance 1 has Collector-1 and Collector-2.

    • Instance 2 has Collector-101 and Collector-102.

  • The collectors on Instance 1 have a sampling rate of 1:10000.

  • The collectors on Instance 2 have a sampling rate of 1:1.

  • Instance 1 collectors have a source and destination address of 10.1.1.1 and 10.2.2.1, respectively.

  • Instance 2 collectors have a source and destination address of 10.11.1.1 and 10.12.2.1, respectively.

  • The packets are exported to the collectors in an IPFIX encapsulated format.

To configure inline monitoring services:

  1. Define a firewall filter for each inline-monitoring instance for servicing the inline monitoring services. You can configure a family firewall filter with the term action inline-monitoring-instance.

    To define a firewall filter:

    In this example, Terms t1 and t2 are configured for Instance1 and Instance2, respectively.

  2. Enable inline monitoring services by configuring the associated template, instance, and collector parameters.
    1. To configure the inline monitoring services template:

      In this example, templates template-1 and template-2 are configured.

    2. To configure inline monitoring instance and collector parameters:

      For Junos OS:

      In this example for Junos OS, Instance1 has two collectors, collector-1 and collector-2, and Instance2 has two collectors, collector-101 and collector-102. Different sampling rates have been configured for both the instances.

      For Junos OS Evolved:

      In this example, for Junos OS Evolved, Instance1 has two collectors, collector-1 and collector-2, and Instance2 has two collectors, collector-101 and collector-102. Different sampling rates have been configured for both the instances.

  3. Map the firewall filter under the family of the logical unit of the interface to apply inline monitoring in the ingress or egress direction.

    Alternatively, you can apply inline monitoring by mapping the firewall filter to a forwarding table filter with an input or output statement to filter ingress or egress packets, respectively.

    To attach the firewall filter:

    In this example, the inline monitoring filter is attached to family inet of unit 0 of et-1/0/0.

Release History Table
Release
Description
22.3R1
Inline monitoring services (MX304 routers) - Starting in Junos OS Release 22.3R1, you can configure inline monitoring services on the MX304 router.
22.2R1-EVO
Inline monitoring services (PTX10001-36MR, PTX10004, PTX10008, and PTX10016 routers with either the JNP10K-LC1201 or JNP10K-LC1203 linecards) - Starting in Junos OS Evolved Release 22.1R1, you can configure inline monitoring services on the PTX10001-36MR, PTX10004, PTX10008, and PTX10016 routers. You can also configure the any, ccc, ethernet-switch, inet, inet6, or mpls family firewall filters with the term action inline-monitoring-instance inline-monitoring-instance-name.
21.4R1
Inline monitoring services (LC9600 linecard for the MX10008 router) - Starting in Junos OS Release 21.4R1, you can configure inline monitoring services on MX10008 routers that contain the LC9600 linecard.
21.2R1
Support for Layer 2 and any firewall filter families for inline monitoring services (MX Series with MPC10E and MPC11E linecards)—Starting in Junos OS Release 21.2R1, you can configure the any, bridge, ccc, mpls, or vpls family firewall filters with the term action inline-monitoring-instance inline-monitoring-instance-name.
21.2R1
Inline monitoring services (LC480 linecard for MX10008 and MX10016 routers - Starting in Junos OS Release 21.2R1, you can configure inline monitoring services on MX10008 and MX10016 routers that contain the LC480 linecard.
21.1R1
Support for Layer 2 and any firewall filter families for inline monitoring services (MX Series with MPCs excluding MPC10E and MPC11E linecards)—Starting in Junos OS Release 21.1R1, you can configure the any, bridge, ccc, mpls, or vpls family firewall filters with the term action inline-monitoring-instance inline-monitoring-instance-name.
20.4R1
Inline monitoring services (MPC10E and MPC11E linecards for MX Series routers - Starting in Junos OS Release 20.4R1, you can configure inline monitoring services on MX Series routers that contain the MPC10E and MPC11E linecards.
19.4R1
Inline monitoring services (MX Series with MPCs excluding MPC10E and MPC11E linecards) - Starting in Junos OS Release 19.4R1, you can configure a new monitoring technology that provides the flexibility to monitor different streams of traffic at different sampling rates on the same interface. You can also export the packet up to the configured clip length to a collector in an IP Flow Information Export (IPFIX) format. The IPFIX format includes important metadata information about the monitored packets for further processing at the collector.