How to block a specific domain or website

To block a specific domain in NetSecWall on Windows, add it to a content category that is set to Block: open Protection ▸ Content categories…, select the category, type the domain in the add box and click Add. The domain and all its subdomains are then blocked like the rest of that category — by the IP addresses they resolve to. This is the only way to block a particular domain; there is no URL or page-level blocking.

Block a specific domain step by step

1. Open Protection ▸ Content categories… (enter the settings password if asked).
2. Click the category you want to put the domain in. The next section helps you choose.
3. In the box Add a domain to this category (e.g., tracker.example.com)…, type the domain, for example example.com.
4. Click Add. The domain appears in the category's list marked (custom).
5. Make sure Block is ticked for that category.

The block takes effect the next time a program on the PC looks the domain up.

Which category to put it in

There is no separate "custom" category, so the domain is blocked together with everything else in the category you choose. If that category isn't blocked yet, ticking Block blocks its whole list as well. So pick a category you already block, or one you are happy to block in full — Scam / Phishing is a natural home for a domain you distrust. A custom domain belongs to one category at a time; adding it to a second one moves it.

How the domain is matched

• Subdomains are included. Adding example.com also covers www.example.com, mail.example.com and any other subdomain.
• A subdomain doesn't cover its parent. Adding ads.example.com blocks that name and names under it, but not example.com.
• Extras are stripped. A leading www. is dropped, and if you paste a full URL, only the host name is kept.
• A name needs a dot. Entries without one are ignored.
• No paths. You can't block example.com/videos on its own. NetSecWall never sees URLs, so it is the whole domain or nothing.

How the block is enforced

A custom domain works exactly like the category lists. When a program looks the domain up through Windows, NetSecWall adds the public addresses it resolves to to its block rules. That has the same limits described in block website categories:

• The first packets to a brand-new address can get through before the block is in place.
• Other sites that share the same address, common on CDNs, are blocked too.
• A browser using its own encrypted DNS hides the lookup, so the block can be missed.

Custom domains survive list updates

Your own domains are stored separately from the downloaded lists, so Update lists and the daily refresh never remove them. To back them up or copy them to another PC, click Export… in the Content categories window (or File ▸ Export settings…); Import… loads such a file and replaces your current category settings and custom domains.

Remove a domain, or make an exception

Select the domain in the category's list and click Delete selected. A custom domain is simply removed. A domain that came from a downloaded list becomes an exception: NetSecWall stops treating it as part of that category, which is how you unblock a site the lists caught by mistake.

Block an address instead

If the site always uses the same fixed address, you can block that address with a custom firewall rule (Remote addresses). Most large sites change addresses and share them with others, so the domain method above is usually the better fit.