Hi all, If I set loopback interface IP as discovery transport-address in MPLS configuration the DEBUG output is: [CUT] 2019/01/17 12:05:19 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address 2019/01/17 12:05:23 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address 2019/01/17 12:05:27 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address 2019/01/17 12:05:32 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address 2019/01/17 12:05:36 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address 2019/01/17 12:05:40 LDP: nbr_establish_connection: error while binding socket to 1.1.1.1: Cannot assign requested address [/CUT] but if I use the physical interface all works good. This is the configuration: vrf VRF-PUBLIC ! interface dummy0 vrf VRF-PUBLIC description Loopback0 ip address 1.1.1.1/32 ! interface enp2s0f0 vrf VRF-PUBLIC description P2P01 ip address 2.2.2.2/30 ip ospf network point-to-point ! interface enp2s0f2 vrf VRF-PUBLIC description P2P02 ip address 3.3.3.3/30 ip ospf network point-to-point ! mpls ldp router-id 1.1.1.1 dual-stack cisco-interop ! address-family ipv4 discovery transport-address 1.1.1.1 label local advertise explicit-null ! interface enp2s0f0 interface enp2s0f1 ! exit-address-family ! ! The FRR version is 6.0.2 and I need to use MPLS on two interfaces (enp2s0f0 and enp2s0f1). thank you for your help regards Alessio