MPLS Configuration

CCIE Jan 10, 2011


  • Enable CEF switching
  • Configure LDP on every label-enabled interface


  • Configure MPLS ID
  • Configure MTU size for labelled packets
  • Configure IP TTL propagation
  • Configure conditional label advertising


mpls ldp router-id interface [force]

router(config-if)# mpls ip

router(config-if)#mpls label protocol [tdp|ldp|both]   #!IOS v12.4(3) the default is now ldp – tdp was previously

router(config-if)#mpls mtu bytes

router(config)#mpls ip propagate-ttl [forwarded | local] #\ default is enabled

router(config)#mpls ldp advertise-labels [for <prefix-acl> [to <peer-acl>]]

Show/Debug Commands;

sh mpls ldp parameters
show mpls interfaces
show mpls ldp discovery
sh mpls ldp neighbor
sh mpls ldp neighbor detail
sho mpls ldp bindings
show mpls forwarding-table
sh ip cef detail

debug mpls ldp ….
debug mpls lfib ….
debug mpls packets [interface]


Rob Edwards

Northern (UK) chap focusing on platforms, automation, cloud and cloud native applications. Recovering network engineer, although it turns out networking is as important, if not more, now than before!