Hi there:

Recently upgraded my Kali EC2 instance:
# uname -a
Linux kali 4.19.0-kali1-amd64 #1 SMP Debian 4.19.13-1kali1 (2019-01-03) x86_64 GNU/Linux

and I'm experiencing problems with its main network interface after the upgrade.

I've got "static" settings via /etc/network/interfaces for 2 network interfaces attached to the instance.
After the upgrade (and reboot) the instance and its IP config looked OK and functioning properly.

At some point though it seems that the main network interface showed no IP config. The other network interface kept working with no issues.
If I restart network services:

# systemctl restart networking.service
Job for networking.service failed because the control process exited with error code.
See "systemctl status networking.service" and "journalctl -xe" for details.

# systemctl status networking.service
● networking.service - Raise network interfaces
Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sun 2019-02-03 10:31:04 AEDT; 5s ago
Docs: man:interfaces(5)
Process: 5389 ExecStartPre=/bin/sh -c if [ "$CONFIGURE_INTERFACES" != "no" ] && [ -n "$(ifquery --read-environment --list --exclude=lo)" ]; then udevadm settle; fi (code=exited, status=0/SUCCESS)
Process: 5392 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1/FAILURE)
Main PID: 5392 (code=exited, status=1/FAILURE)


Feb 03 10:31:04 kali dhclient[5423]: DHCPACK of 10.255.0.155 from 10.255.0.129
Feb 03 10:31:04 kali ifup[5392]: DHCPACK of 10.255.0.155 from 10.255.0.129
Feb 03 10:31:04 kali ifup[5392]: RTNETLINK answers: File exists
Feb 03 10:31:04 kali dhclient[5423]: bound to 10.255.0.155 -- renewal in 1518 seconds.
Feb 03 10:31:04 kali ifup[5392]: bound to 10.255.0.155 -- renewal in 1518 seconds.
Feb 03 10:31:04 kali ifup[5392]: RTNETLINK answers: File exists
Feb 03 10:31:04 kali ifup[5392]: ifup: failed to bring up eth0
Feb 03 10:31:04 kali systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
Feb 03 10:31:04 kali systemd[1]: networking.service: Failed with result 'exit-code'.
Feb 03 10:31:04 kali systemd[1]: Failed to start Raise network interfaces.



But the IP config in main interface is back, until lease time expires. Then, the problem repeats itself.

I created the file "/etc/cloud/cloud.cfg.d/99-disable-network-config.cfg" with content network: {config: disabled}, as suggested in /etc/network/interfaces.d/50-cloud-init.cfg but that didn't fix anything.

Any ideas on how to fix this?
Thanks!
Juan.