no-propagate-ttl
Syntax
Hierarchy Level
Release Information
Statement introduced before Junos OS Release 7.4.
Statement introduced in Junos OS Release 12.3X50 on the QFX Series.
Statement introduced in Junos OS Evolved Release 20.1R1 on PTX10008.
Description
Disable normal time-to-live (TTL) decrementing. You configure this statement once per router, and it affects all RSVP-signaled or LDP-signaled LSPs. When this router acts as an ingress router for an LSP, it pushes an MPLS header with a TTL value of 255, regardless of the IP packet TTL. When the router acts as the penultimate router, it pops the MPLS header without writing the MPLS TTL into the IP packet.
When you add the no-propagate-ttl statement to the configuration or delete it from the configuration, the effect takes place immediately. There is no need to clear existing RSVP LSPs or LDP sessions.
Default
Normal TTL decrementing enabled; the TTL field value is decremented by 1 as the packet passes through each label-switched router in the LSP.
Required Privilege Level
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
Related Documentation
Example: Diagnosing Networking Problems Related to Layer 3 VPNs by Disabling TTL Decrementing (on Layer 3 VPNs User Guide for Routing Devices or in the Junos VPNs Configuration Guide)