Manually 'down' and interface (physical link - i.e. no link light)

[luckman212]

An ISP vendor is troubleshooting an issue at a remote site and has asked me to "unplug the Cat5 handoff from our equipment" while they do some tests or config.  There's nobody there who can physically unplug the cable now, but I do have access through a secondary WAN to ssh in and run commands.  But- I noticed that simply running e.g.

ifconfig igb2 down

Does not actually take the interface "down" - it goes down programmatically but the link lights are still up.  I google'd a bit and found a couple of other pages that seem to confirm this is a limitation of FreeBSD.  One guy seems to have written his own patch for em and igb interfaces.
https://forums.freebsd.org/threads/52718/
https://mebsd.com/make-build-your-freebsd-word/ifconfig-physical-link-down.html

Just came to ask if anyone knows of any way to do this, seems it could be potentially useful.

[robi]

That would be a nice feature. Bring an interface "administratively" down so that the LEDs stop blinking too and the physical link status breaks. Like cisco equipment.