User talk:HRio
Seems that vrf-mgmt is not end up in state UP. Needed to do like follows
auto vrf-mgmt iface vrf-mgmt inet manual pre-up ip link add $IFACE type vrf table 42 up ip link set dev $IFACE up
auto eth0 iface eth0 inet static address 1.2.3.4 netmask 255.255.255.0 gateway 1.2.3.1 pre-up ip link set $IFACE master vrf-mgmt