How to make Wake on Lan persistent in Debian buster?

I am on Debian 10 buster. Output of sudo ifconfig -a is

enp0s7: flags=xxxx<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.xx.xxx  netmask 255.255.xxx.x  broadcast 192.168.xx.xxx
        inet6 xxxx:xxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx  prefixlen xx  scopeid 0x0<global>
        inet6 xxxx::xxxx:xxxx:xxxx:xxxx  prefixlen xx  scopeid 0x20<link>
        inet6 xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx  prefixlen xx  scopeid 0x0<global>
        ether xx:xx:xx:xx:xx:xx  txqueuelen 1000  (Ethernet)
        RX packets 68866  bytes 72160614 (68.8 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 33033  bytes 5158947 (4.9 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 4  bytes 240 (240.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4  bytes 240 (240.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

output of cat cat /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

I tried to add only a line like /sbin/ethtool -s enp0s7 wol g in above file. But wake on lan still shows d after reboot.

output before

Settings for enp0s7:
    Supported ports: [ MII ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Supported pause frame use: No
    Supports auto-negotiation: Yes
    Supported FEC modes: Not reported
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Advertised pause frame use: No
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Speed: 1000Mb/s
    Duplex: Full
    Port: MII
    PHYAD: 1
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: g
    Wake-on: d
    Link detected: yes

output after sudo /sbin/ethtool -s enp0s7 wol g

Settings for enp0s7:
    Supported ports: [ MII ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Supported pause frame use: No
    Supports auto-negotiation: Yes
    Supported FEC modes: Not reported
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Advertised pause frame use: No
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Speed: 1000Mb/s
    Duplex: Full
    Port: MII
    PHYAD: 1
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: g
    Wake-on: g
    Link detected: yes

I enabled wake on lan(wake on pcie) in bios.
I think I need to add more lines in /etc/network/interfaces to make it work. Suggest a fix.

You have to create a service dedicated to enable your WOL at startup :

$ cat /etc/systemd/system/wol.service
[Unit]
Description=Configure Wake-up on LAN

[Service]
Type=oneshot
ExecStart=/sbin/ethtool -s eth0 wol g

[Install]
WantedBy=basic.target

Then enabling the service with :

sudo systemctl enable wol.service
sudo systemctl daemon-reload

And finally, reboot the machine or server and check configuration with sudo ethtool eth0

Source : French documentation of Debian WOL

cat /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

I tried to add only a line like /sbin/ethtool -s enp0s7 wol g in above file.

Instead of adding above line. Add this:

ethernet-wol g

In order to make Wake on Lan persistent in Debian buster, you need to edit the configuration file and change the line containing “1”.