- play_arrow Overview
- play_arrow Understanding MPLS
- play_arrow Supported Standards
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- play_arrow MPLS Configuration
- play_arrow Configuring MPLS
- play_arrow Configuring MPLS Tunnels
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- play_arrow MPLS Traffic
- play_arrow Managing MPLS Traffic
- play_arrow Protecting MPLS Traffic
- play_arrow Measuring MPLS Traffic
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- play_arrow MPLS LSPs
- play_arrow Understanding MPLS LSPs
- play_arrow Configuring MPLS LSPs
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- play_arrow MPLS Traffic Engineering
- play_arrow Configuring MPLS Traffic Engineering
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- play_arrow MPLS Transport Profile
- play_arrow Operation, Administration, and Maintenance (OAM) for MPLS
- play_arrow MPLS Pseudowires
- play_arrow Class-of-Service (CoS) for MPLS
- play_arrow Generalized MPLS (GMPLS)
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- play_arrow MPLS VPNs and Circuits
- play_arrow Ethernet over MPLS (L2 Circuit)
- play_arrow CCC, TCC, and Layer 2.5 Switching
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- play_arrow MPLS for Software Defined Networking (SDN)
- play_arrow Path Computation Element Protocol (PCEP)
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- play_arrow MPLS Troubleshooting
- play_arrow Troubleshooting MPLS
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- play_arrow Configuration Statements and Operational Commands
ON THIS PAGE
MPLS TTL Propagation Flexibility for LDP-signaled LSPs
We support disabling time-to-live (TTL) propagation at a more granular level. You can disable TTL propagation specifically for LDP-signaled label-switched paths (LSPs). When a route is very long, disable TTL propagation to ensure that the TTL doesn't expire while the packet is traversing the path. This feature also gives you more flexibility in hiding your network topology.
To disable TTL propagation for LDP-signaled LSPs, use the no-propagate-ttl statement at the
[edit protocol ldp] hierarchy level.
If the TTL value of the top label is less than the TTL value of the bottom label at an egress node, Junos OS copies the TTL value from the top label to the bottom label. In this case, the TTL value can still propagate down even when no-propagate-ttl is configured.
[See no-propagate-ttl.]
Purpose
The purpose is to support the configuration and functionality of the
no-propagate-ttl option at the [edit protocol ldp]
hierarchy.
LDP No Propagate TTL Configuration
The following command results in LDP following the no propagate TTL behavior.
set protocol ldp no-propagate-ttl
If you configure the global no-propagate-ttl option with this command,
there is no change in behavior.
The no-propagate-ttl option has no impact on the independent RSVP LSP.
However, when you use this option with LDPoRSVP, the TTL action of the RSVP LSP decides the
TTL propagation behavior.
This means that when the router is acting as an ingress node for LDP and RSVP for the
LDPoRSVP LSP, if you configure no-decrement-ttl for the RSVP LSP, then the
LDPoRSVP does not propagate TTL. And if you don't configure the
no-decrement-ttl option for the RSVP LSP, then it propagates TTL.
