StrongSwan IKEv2 VPN config tutorial

Following this tutorial : => https://www.digitalocean.com/community/tutorials/how-to-set-up-an-ikev2-vpn-server-with-strongswan-on-ubuntu-20-04#prerequisites

step 6 has us do ip route show default

and sample output is : Output default via your_server_ip dev eth0 proto static

Then in editing the /etc/ufw/before.rules we need to insert

*nat -A POSTROUTING -s 10.10.10.0/24 -o eth0 -m policy --pol ipsec --dir out -j ACCEPT -A POSTROUTING -s 10.10.10.0/24 -o eth0 -j MASQUERADE COMMIT

The text states : “Near the top of the file (before the *filter line), add the following configuration block. Change each instance of eth0 in the above configuration to match the interface name you found with ip route.”

What is the ‘interface name’ referred to there ? If the author meant your_server_ip he would have stated that. In any case my ‘your_server_ip’ is not in the 10.10.10.0/24 range…

Anyway I don’t understand what this bit means.

Thanks for any assistance.