I've observed the following issues with dhcp-interface static routes:
- Setting the interface to DHCP and adding a dhcp-interface static route in the same commit doesn't add the route to FRR.
- Renewing the DHCP lease after changing the default-router option or renumbering the network doesn't update the dhcp-interface next-hop in FRR.
- Rebooting after changing the default-router option or renumbering the network leaves the old dhcp-interface next-hop in FRR.
More info for #3:
vyos@vyos:~$ show configuration commands set interfaces ethernet eth0 address 'dhcp' set interfaces ethernet eth0 hw-id '0c:3f:c4:82:3f:00' set interfaces loopback lo set protocols static route 10.1.0.0/24 dhcp-interface 'eth0' set system config-management commit-revisions '100' set system console device ttyS0 speed '115200' set system host-name 'vyos' set system login user vyos authentication encrypted-password '$6$nl8G/LLSeS3igU' set system login user vyos authentication plaintext-password '' set system ntp server time1.vyos.net set system ntp server time2.vyos.net set system ntp server time3.vyos.net set system syslog global facility all level 'info' set system syslog global facility protocols level 'debug' vyos@vyos:~$ show interfaces Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down Interface IP Address S/L Description --------- ---------- --- ----------- eth0 10.0.2.10/24 u/u lo 127.0.0.1/8 u/u ::1/128 vyos@vyos:~$ vtysh -c 'show running-config' Building configuration... Current configuration: ! frr version 7.5.1-20201222-185-gb3f4ff1d9 frr defaults traditional hostname vyos log syslog log facility local7 service integrated-vtysh-config ! ip route 10.1.0.0/24 10.0.1.1 ! line vty ! end vyos@vyos:~$ cat /var/lib/dhcp/dhclient_eth0.leases lease { interface "eth0"; fixed-address 10.0.1.10; option subnet-mask 255.255.255.0; option routers 10.0.1.1; option dhcp-lease-time 86400; option dhcp-message-type 5; option dhcp-server-identifier 10.0.1.1; renew 2 2021/07/13 18:16:10; rebind 2 2021/07/13 18:16:10; expire 2 2021/07/13 18:16:10; } lease { interface "eth0"; fixed-address 10.0.2.10; option subnet-mask 255.255.255.0; option routers 10.0.2.1; option dhcp-lease-time 86400; option dhcp-message-type 5; option dhcp-server-identifier 10.0.2.1; renew 3 2021/07/14 05:25:46; rebind 3 2021/07/14 15:16:38; expire 3 2021/07/14 18:16:38; }