Debian 10 DSR Target Setup

Setup an additional IPv4 loopback alias in /etc/network/interfaces

Add the following to /etc/network/interfaces replacing index and the IPv4 address with the address of your virtual server:

auto lo:index
iface lo:index inet static
        address IPv4-address
        netmask 255.255.255.255

For example: If your virtual server was 10.1.1.8 and you decided to use index 0, you need to add the following:

auto lo:0
iface lo:0 inet static
        address 10.1.1.8
        netmask 255.255.255.255

Make sure to specify the netmask 255.255.255.255 (and nothing else). The index may be any number starting with 0.

Setup an additional IPv6 loopback alias in /etc/network/interfaces

Add the following to /etc/network/interfaces replacing the IPv6 address with the address of your virtual server:

iface lo inet6 static
  address IPv6-address
  netmask 128

For example: If your virtual server was 2001:db8::2:4 you just need to add the following:

iface lo inet6 static
  address 2001:db8::2:4
  netmask 128

For IPv6 it’s important to specify netmask 128, this makes that the specified address has no network part (covering all 128 bits).

Disable unwanted ARP requests in /etc/sysctl.conf (required for IPv4 only)

Just add the following two lines at the end of /etc/sysctl.conf:

net.ipv4.conf.all.arp_ignore=1
net.ipv4.conf.all.arp_announce=2

sometimes /etc/sysctl.conf gets overwritten during an update, so in case of ARP problems check if this entry is present on all targets.