I'm going through the documentation at the moment and saw that interface ethernet <iface> disable was not documented so I wanted to test that.
On a simple Hyper-V VM with 1.2.0-rc11 I just set up eth0 with dhcp and everything worked as expected, I got address and everything.
vyos@vyos:~$ show interfaces
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 10.20.30.107/24 u/u
eth1 172.17.144.146/28 u/u
lo 127.0.0.1/8 u/u
::1/128set interface ethernet eth0 disable also worked as expected. The interface went down.
vyos@vyos:~$ show interfaces
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 - A/D
eth1 172.17.144.146/28 u/u
lo 127.0.0.1/8 u/u
::1/128
vyos@vyos:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 00:15:5d:54:a1:4f brd ff:ff:ff:ff:ff:ff
[...]The interesting part came later when I tried to re-enable the interface. I tried the only obvious way I could see to enable,
delete interface ethernet eth0 disable only to discover that the interface didn't get an IP again.
vyos@vyos:~$ show interfaces
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 - u/u
eth1 172.17.144.146/28 u/u
lo 127.0.0.1/8 u/u
::1/128
vyos@vyos:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:15:5d:54:a1:4f brd ff:ff:ff:ff:ff:ff
inet6 fe80::215:5dff:fe54:a14f/64 scope link
valid_lft forever preferred_lft forever
[...]It looks as if the interface is going up but the dhcp client is not made aware.
When checking for BOOTP/DHCP with Wireshark I saw other activity but nothing from vyos after re-enable.
What I can see relevant log entries for the sequence...
Disable
Jan 22 08:17:43 vyos dhclient[2880]: DHCPRELEASE on eth0 to 10.20.30.21 port 67 Jan 22 08:17:44 vyos bgpd[1903]: [EC 100663301] INTERFACE_ADDRESS_DEL: Cannot find IF 2 in VRF 0 Jan 22 08:17:44 vyos sudo[2879]: pam_unix(sudo:session): session closed for user root Jan 22 08:17:44 vyos sudo[2926]: vyos : TTY=pts/0 ; PWD=/home/vyos ; USER=root ; COMMAND=/bin/rm -f /var/lib/dhcp/dhclient_eth0.pid Jan 22 08:17:44 vyos sudo[2926]: pam_unix(sudo:session): session opened for user root by vyos(uid=0) Jan 22 08:17:44 vyos sudo[2926]: pam_unix(sudo:session): session closed for user root Jan 22 08:17:44 vyos sudo[2928]: vyos : TTY=pts/0 ; PWD=/home/vyos ; USER=root ; COMMAND=/sbin/ip link set eth0 down Jan 22 08:17:44 vyos sudo[2928]: pam_unix(sudo:session): session opened for user root by vyos(uid=0) Jan 22 08:17:44 vyos lldpd[2465]: error while receiving frame on eth0: Network is down Jan 22 08:17:44 vyos bgpd[1903]: [EC 100663301] INTERFACE_STATE: Cannot find IF eth0 in VRF 0 Jan 22 08:17:44 vyos bgpd[1903]: [EC 100663301] INTERFACE_ADDRESS_DEL: Cannot find IF 2 in VRF 0 Jan 22 08:17:44 vyos bgpd[1903]: [EC 100663301] INTERFACE_ADDRESS_DEL: Cannot find IF 2 in VRF 0 [...] Jan 22 08:17:44 vyos commit[2962]: Successful change to active configuration by user vyos on /dev/pts/0 Jan 22 08:17:45 vyos ntpd[2385]: Deleting interface #7 eth0, fe80::215:5dff:fe54:a14f#123, interface stats: received=0, sent=0, dropped=0, active_time=64 secs Jan 22 08:17:45 vyos ntpd[2385]: Deleting interface #3 eth0, 10.20.30.107#123, interface stats: received=12, sent=12, dropped=0, active_time=66 secs Jan 22 08:17:45 vyos ntpd[2385]: 193.228.143.14 interface 10.20.30.107 -> (none) Jan 22 08:17:45 vyos ntpd[2385]: 91.209.0.17 interface 10.20.30.107 -> (none) Jan 22 08:17:45 vyos ntpd[2385]: peers refreshed
delete disable
Jan 22 08:20:50 vyos sudo[3412]: vyos : TTY=pts/0 ; PWD=/home/vyos ; USER=root ; COMMAND=/sbin/ip link set eth0 up Jan 22 08:20:50 vyos sudo[3412]: pam_unix(sudo:session): session opened for user root by vyos(uid=0) Jan 22 08:20:50 vyos bgpd[1903]: [EC 100663301] INTERFACE_STATE: Cannot find IF eth0 in VRF 0 Jan 22 08:20:50 vyos bgpd[1903]: [EC 100663301] INTERFACE_STATE: Cannot find IF eth0 in VRF 0 Jan 22 08:20:50 vyos sudo[3412]: pam_unix(sudo:session): session closed for user root Jan 22 08:20:50 vyos sudo[3411]: vyos : TTY=pts/0 ; PWD=/home/vyos ; USER=root ; COMMAND=/opt/vyatta/sbin/irq-affinity.pl eth0 auto Jan 22 08:20:50 vyos sudo[3411]: pam_unix(sudo:session): session opened for user root by vyos(uid=0) Jan 22 08:20:50 vyos irq-affinity[3414]: cpus=2 cores=1 threads=2 sockets=1 Jan 22 08:20:50 vyos sudo[3411]: pam_unix(sudo:session): session closed for user root Jan 22 08:20:50 vyos sudo[3441]: vyos : TTY=pts/0 ; PWD=/home/vyos ; USER=root ; COMMAND=/bin/mv /tmp/config.boot.3435 /opt/vyatta/etc/config/archive/config.boot