On an LER, when the packet is a locally originated IP packet, MPLS copies the TTL of all pushed MPLS labels from the IP header when the local option for the mpls ip propagate-ttl command has been configured. When the no mpls ip propagate-ttl local command has been configured, MPLS sets the TTL to 255.
When the packet is a forwarded IP or MPLS packet, MPLS copies the TTL of all pushed labels from the inner IP or MPLS header when the forwarded option for the mpls ip propagate-ttl command has been configured. When the no mpls ip propagate-ttl forwarded command has been configured, MPLS sets the TTL for these pushed labels to 255.
When the packet is neither IP nor MPLS, such as a Martini packet, MPLS sets the TTL of all pushed labels to 255.
Figure 52: TTL Processing on Outgoing MPLS Packets
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