https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=221122
--- Comment #19 from Mason Loring Bliss <ma...@blisses.org> --- I saw this issue on FreeBSD 13.0-RELEASE, and following kbowling's recommendation, also tried the most recent 13-STABLE images. This latter is where I've gathered data. Same issue: Add an epair half to a bridge and things go away for several seconds. The delay is quite possibly longer in -STABLE but I might be imagining it. Either way, documented below. Note that on literally the same hardware, the same operations cause no delay under Debian Bullseye: Have a bridge, add a vnet device to it, and everything keeps flowing without interruption, which is useful since these boxes are hypervisors and running a variety of generally network-oriented tasks. # freebsd-version -ku ; uname -a 13.0-STABLE 13.0-STABLE FreeBSD amazon.int.blisses.org 13.0-STABLE FreeBSD 13.0-STABLE #0 stable/13-n248302-2cd26a286a9: Thu Dec 2 02:40:58 UTC 2021 r...@releng3.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64 # dmesg | tail uhid0 on uhub3 uhid0: <Logitech USB Keyboard, class 0/0, rev 1.10/79.00, addr 3> on usbus1 Security policy loaded: MAC/ntpd (mac_ntpd) epair0a: Ethernet address: 02:52:8f:32:b1:0a epair0b: Ethernet address: 02:52:8f:32:b1:0b epair0a: link state changed to UP epair0b: link state changed to UP igb0: link state changed to DOWN epair0a: promiscuous mode enabled igb0: link state changed to UP # dmesg | grep igb0 igb0: <Intel(R) I350 (Copper)> mem 0xfb720000-0xfb73ffff,0xfb7c4000-0xfb7c7fff irq 40 at device 0.0 on pci3 igb0: EEPROM V0.93-0 eTrack 0x800006b2 igb0: Using 1024 TX descriptors and 1024 RX descriptors igb0: Using 6 RX queues 6 TX queues igb0: Using MSI-X interrupts with 7 vectors igb0: Ethernet address: 00:25:90:a6:a5:60 igb0: netmap queues/slots: TX 6/1024, RX 6/1024 igb0: promiscuous mode enabled igb0: link state changed to UP igb0: link state changed to DOWN igb0: link state changed to UP /home/mason$ date ; ssh root@amazon ifconfig bridge0 addm epair0a ; date Mon 06 Dec 2021 10:36:37 PM EST Mon 06 Dec 2021 10:36:41 PM EST /home/mason$ date ; ssh root@amazon ifconfig bridge0 deletem epair0a ; date Mon 06 Dec 2021 10:37:00 PM EST Mon 06 Dec 2021 10:37:05 PM EST /home/mason$ date ; ssh root@amazon date ; date Mon 06 Dec 2021 10:38:14 PM EST Mon Dec 6 22:38:14 EST 2021 Mon 06 Dec 2021 10:38:14 PM EST -- You are receiving this mail because: You are the assignee for the bug.