We must add ifname pppoeX to /etc/ppp/peers/pppoeX for interfaces renaming in equuleus, otherwise interface won't renamed.
vyos@R3# run show configuration commands | match pppoe set interfaces ethernet eth1 pppoe 1 default-route 'none' set interfaces ethernet eth1 pppoe 1 password 'vyos' set interfaces ethernet eth1 pppoe 1 user-id 'vyos' vyos@R3# sudo ip link show dev ppp1 18: ppp1: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 3 link/ppp