When habing a DHCP interface placed in a VRF the default route received via DHCP is not added to the VRFs routing table.
Instead the main routing table is used.
Apr 12 13:21:29 vyos dhclient[3632]: DHCPOFFER of 172.16.33.125 from 172.16.33.254 Apr 12 13:21:29 vyos dhclient[3632]: DHCPREQUEST for 172.16.33.125 on wlan0 to 255.255.255.255 port 67 Apr 12 13:21:29 vyos dhclient[3632]: DHCPACK of 172.16.33.125 from 172.16.33.254 Apr 12 13:21:29 vyos dhclient-script-vyos[3690]: Current dhclient PID: 3632, Parent PID: 1, IP version: -4, All dhclients for interface wlan0: 3632 Apr 12 13:21:29 vyos dhclient-script-vyos[3690]: Passing command to /usr/sbin/ip: "-4 addr add 172.16.33.125/255.255.255.0 broadcast 172.16.33.255 valid_lft 86400 preferred_lft 86400 dev wlan0 label wlan0" Apr 12 13:21:30 vyos dhclient-script-vyos[3690]: FRR status: running Apr 12 13:21:30 vyos dhclient-script-vyos[3690]: Checking if the route presented in kernel: default via 172.16.33.254 dev wlan0 Apr 12 13:21:30 vyos dhclient-script-vyos[3690]: Converted vtysh command: "ip route 0.0.0.0/0 172.16.33.254 wlan0 tag 210 210" Apr 12 13:21:30 vyos dhclient-script-vyos[3690]: Sending command to vtysh Apr 12 13:21:30 vyos staticd[1008]: Static Route using wlan0 interface not installed because the interface does not exist in specified vrf Apr 12 13:21:30 vyos dhclient-script-vyos[3690]: Adding search-domain "vyos.net" via vyos-hostsd-client
set interfaces wireless wlan0 address 'dhcp' set interfaces wireless wlan0 channel '0' set interfaces wireless wlan0 description 'foo bar baz 1234' set interfaces wireless wlan0 hw-id 'XX:XX:XX:XX:XX:c3' set interfaces wireless wlan0 mgmt-frame-protection 'disabled' set interfaces wireless wlan0 mode 'g' set interfaces wireless wlan0 physical-device 'phy0' set interfaces wireless wlan0 security wpa passphrase 'VyOSVyOS123' set interfaces wireless wlan0 ssid 'VYOS-NET' set interfaces wireless wlan0 type 'station' set interfaces wireless wlan0 vrf 'black'
A hint could be the implementation from https://github.com/vyos/vyos-1x/blob/current/data/templates/pppoe/ip-up.script.tmpl