Safe DNS

You can use free DNS that does not require public IP. Here is the one I am very happy with (Norton ConnectSafe):
Policy A — Security
This policy blocks all sites hosting malware, phishing sites, and scam sites. To choose Policy A, use the following IP addresses as preferred and alternate DNS server addresses:
199.85.126.10
199.85.127.10

Policy B — Security + Pornography
In addition to blocking unsafe sites, this policy also blocks access to sites that contain sexually explicit material. To choose Policy B, use the following IP addresses as preferred and alternate DNS server addresses:
199.85.126.20
199.85.127.20

Policy C — Security + Pornography + Non-Family Friendly
This policy is ideal for families with young children. In addition to blocking unsafe sites and pornography sites, this policy also blocks access to sites that feature mature content, abortion, alcohol, crime, cults, drugs, gambling, hate, sexual orientation, suicide, tobacco, or violence. To choose Policy C, use the following IP addresses as preferred and alternate DNS server addresses
199.85.126.30
199.85.127.30

Sources:
https://en.wikipedia.org/wiki/Norton_ConnectSafe
https://dns.norton.com/configureRouter.html

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AdGuard DNS


Default: Use these servers to block ads, tracking and phishing
176.103.130.130
176.103.130.131

Or use IPv6 addresses
2a00:5a60::ad1:0ff
2a00:5a60::ad2:0ff

Family protection: Default + blocking adult websites + safe search
176.103.130.132
176.103.130.134

Or use IPv6 addresses
2a00:5a60::bad1:0ff
2a00:5a60::bad2:0ff

Ref: https://adguard.com/en/adguard-dns/overview.html

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Ad-blocking DNS

Use the following DNS servers:
Primary: 23.253.163.53
Secondary: 198.101.242.72

Ref: https://www.instructables.com/id/Block-Ads-With-Your-Router-Using-Ad-blocking-DNS-S/