ifconfig_em0: DHCP NOAUTO

With *NOAUTO* (for the interface to be n*ot* be configured at boot)

When, some time after boot, I *do* want to use the interface, what steps 
are required for
/var/run/resolvconf/interfaces/em0
to be created?

Example context:


% date ; uptime
Sat 26 Nov 2022 15:00:11 GMT
3:00p.m.  up 10 mins, 8 users, load averages: 0.36, 1.05, 0.75
% sysrc ifconfig_em0 ifconfig_wlan0 cloned_interfaces
ifconfig_em0: DHCP NOAUTO
ifconfig_wlan0: WPA DHCP
cloned_interfaces: gif0
% ls /var/run/resolvconf/interfaces/
wlan0
% cat /var/run/resolvconf/interfaces/wlan0
search lan
nameserver 192.168.1.1
nameserver 192.168.1.1
% ifconfig em0 | grep -e inet -e status
        inet 192.168.1.10 netmask 0xffffff00 broadcast 192.168.1.255
        status: active
% su -
Password:
root@mowa219-gjp4-8570p-freebsd:~ # grep em0 /var/log/dmesg.today | grep 
-v -e umodem0 -e address
em0: <Intel(R) 82579LM> port 0x3020-0x303f mem 
0xd0400000-0xd041ffff,0xd043a000-0xd043afff at device 25.0 on pci0
em0: EEPROM V0.15-4
em0: Using 1024 TX descriptors and 1024 RX descriptors
em0: Using an MSI interrupt
em0: netmap queues/slots: TX 1/1024, RX 1/1024
ahciem0: <AHCI enclosure management bridge> on ahci0
ses0 at ahciem0 bus 0 scbus2 target 0 lun 0
em0: link state changed to UP
debugnet_any_ifnet_update: Bad dn_init result from em0 (ifp 
0xfffff80001b88000), ignoring.
em0: link state changed to DOWN
em0: link state changed to UP
em0: link state changed to DOWN
em0: link state changed to UP
root@mowa219-gjp4-8570p-freebsd:~ #


gif0 is sometimes used for a tunnel between 192.168.1.10 and an IPv6 
tunnel broker.