Idid a systemctl restart networking and it broke Proxmox VM connectivity!
#proxmox is the problem after restarting the network the tap devices go to disabled state
[2230884.919905] vmbr0: port 7(tap118i0) entered disabled state
[2230884.948864] vmbr0: port 8(tap122i0) entered disabled state
[2230884.972748] vmbr0: port 6(tap119i0) entered disabled state
[2230885.004745] vmbr0: port 5(tap117i0) entered disabled state
[2230885.03673........
ip tunnel add tun3 mode gre remote 192.58.1.5 ttl 64
ioctl: no such device
I solved this on Centos by loading the ip_gre module:
modprobe ip_gre
On Debian I believe it is the "sit" module.........