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ttl (RPM probe)


Junos OS Hierarchy Level

Junos OS Evolved Hierarchy Level


Specify the maximum hop count (TTL) for all types of probes (IPv4 and IPv6) in real-time performance monitoring (RPM) and Two-Way Active Management Protocol (TWAMP). This can be useful when it is necessary to restrict the scope of the RPM probes so a probe does not unintentionally monitor an alternative path to the destination (such as may occur after a BGP re-routing). Another example is to monitor direct reachability by specifying a TTL of 1. Probes that exceed the number set for TTL are discarded.

The TTL configuration is supported on Routing Engine-based RPM, Multiservices Modular PIC Concentrator (MS-MPC) and Multiservices Modular Interfaces Card (MS-MIC)-based RPM, and Two-Way Active Management Protocol (TWAMP).

You can set a TTL value for the probe types listed below.

Software time stamping:

  • icmp-ping, and icmp-ping-timestamp

  • icmp6-ping (Junos OS only)

  • udp-ping, and udp-ping-timestamp

  • tcp-ping (Junos OS only)

  • http-get, and http-metadata-get (Junos OS only)

  • BGP neighbor monitoring using TCP/UDP (Junos OS only)

Hardware time stamping:

  • icmp-ping and icmp-ping-timestamp

  • udp-ping and udp-ping-timestamp

MS-MPC-PIC based probes (delegate):

  • icmp-ping, icmp-ping-timestamp, and icmp6-ping (Junos OS only),

MS-MPC-PIC hardware timestamp:

  • icmp-ping and icmp-ping-timestamp

  • udp-ping and udp-ping-timestamp

TWAMP probe:

  • inline TWAMP client


hop-count—Prior to Junos OS Release 18.2R1, for RPM, the RPM client always sent a TTL of 64 to the RPM server under the IPv4 or IPv6 header. For TWAMP clients, the TTL was 255 sent in the IPv4 header. In Junos OS Release 18.2R1 and later, you can specify the TTL you want for RPM and TWAMP probes.

  • Range: 1 through 255 for both RPM and TWAMP

  • Default: 64

Required Privilege Level

system—To view this statement in the configuration.

system-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 18.2R1 for MX Series routers.

Statement introduced in Junos OS Evolved Release 20.1R1.