Tutorial Wireguard AllowedIPs Calculator

[mkaand]

Hello Everyone,

I discovered a website called Wireguard AllowedIPs Calculator and it fixes my issue. For this reason I want to share with you. First I want to explain my setup:

Scaleway VDS at Amsterdam - Ubuntu 22 (This is my Wireguard Server actually) Wireguard interface: 10.8.0.0/24
Home Network - ASUS RT-AX86U Router and latest Merlin firmware on it. 192.168.50.0/24
Home Network - Fiber Modem 192.168.1.0/24

ISSUE:
I tried to redirect only specific Public IP address to Wireguard with using VPN Director. But for this I should make Allowed IPs = 0.0.0.0/0. But If my Wireguard server off or rebooting, my router shows red light for WAN traffic and there is no traffic. This was the issue.

SOLUTION:
I realized router tried to send all traffic to Wireguard interface. VPN Director only works after connection turn on. Maybe also DNS issue I don't know. I used below Wireguard AllowedIPs Calculator website and I easily calculated correct Allowed IPs for my setup.

WireGuard AllowedIPs Calculator

How to

www.procustodibus.com

I typed 0.0.0.0/0, ::/0 for Allowed IPs,

AND

I typed 192.168.50.0/24,192.168.1.0/24,1.1.1.1/32,1.0.0.1/32 for Disallowed IPs field and pressed the Calculate button. (1.1.1.1 and 1.0.0.1 are my DNSs)

It tells me bellow AllowedIPs:

0.0.0.0/8,1.0.0.0/32,1.0.0.2/31,1.0.0.4/30,1.0.0.8/29,1.0.0.16/28,1.0.0.32/27,1.0.0.64/26,1.0.0.128/25,1.0.1.0/24,1.0.2.0/23,1.0.4.0/22,1.0.8.0/21,1.0.16.0/20,1.0.32.0/19,1.0.64.0/18,1.0.128.0/17,1.1.0.0/24,1.1.1.0/32,1.1.1.2/31,1.1.1.4/30,1.1.1.8/29,1.1.1.16/28,1.1.1.32/27,1.1.1.64/26,1.1.1.128/25,1.1.2.0/23,1.1.4.0/22,1.1.8.0/21,1.1.16.0/20,1.1.32.0/19,1.1.64.0/18,1.1.128.0/17,1.2.0.0/15,1.4.0.0/14,1.8.0.0/13,1.16.0.0/12,1.32.0.0/11,1.64.0.0/10,1.128.0.0/9,2.0.0.0/7,4.0.0.0/6,8.0.0.0/5,16.0.0.0/4,32.0.0.0/3,64.0.0.0/2,128.0.0.0/2,192.0.0.0/9,192.128.0.0/11,192.160.0.0/13,192.168.0.0/24,192.168.2.0/23,192.168.4.0/22,192.168.8.0/21,192.168.16.0/20,192.168.32.0/20,192.168.48.0/23,192.168.51.0/24,192.168.52.0/22,192.168.56.0/21,192.168.64.0/18,192.168.128.0/17,192.169.0.0/16,192.170.0.0/15,192.172.0.0/14,192.176.0.0/12,192.192.0.0/10,193.0.0.0/8,194.0.0.0/7,196.0.0.0/6,200.0.0.0/5,208.0.0.0/4,224.0.0.0/3,::/0

I added this output to my ASUS router. Result is perfect. If I reboot my server or if connection lost, still I have internet. I would like to share with people. This calculator is very handy. I highly recommend it.