# mpls ip propagate-ttl

#### Syntax

[ no | default ] mpls ip propagate-ttl [ forwarded | local ]

#### Release Information

Command introduced before JunosE Release 7.1.0.

#### Description

Controls the value for the TTL field in the MPLS header at the tunnel ingress when a label is assigned to an IP packet. Enabled by default, this command sets the TTL to the TTL value from the IP packet header.

The no version sets the value to 255 to hide the network structure from all traffic, preventing the traceroute command from discovering and displaying LSP hops. The no version changes the TTL processing model from the default uniform model to the pipe model.

The default version reverts to the global default, causing the TTL field to be copied from the IP packet header and enabling the traceroute command to show all the hops in the network.

#### Options

- forwarded—Reveals the network structure to traceroute for forwarded packets; when used with the no version, hides the network structure from traceroute only for local packets, enabling you to hide the structure of the MPLS network from your customers, and sets the tunnel model to pipe for forwarded packets
- local—Reveals the network structure to traceroute for local packets; when used with the no version, hides the network structure from traceroute only for local packets, sets the tunnel model to pipe for locally originated packets, and sets the tunnel model to pipe for locally originated packets

#### Mode

Global Configuration