Data-Shield IPv4 Blocklists.
Practical threat intelligence.

A small format with a practical purpose.

The official Data-Shield repository publishes curated IPv4 addresses associated with malicious activity, informed by probe observations. Its documented cadence is every six hours, with a rolling 15-day retention window. That window matters: an address should not become a permanent verdict simply because it appeared in an older feed.

I provide general production and critical-infrastructure variants, including full and split files for different capacity limits. Start with the documented purpose of each feed, then check your platform's import format and maximum entries. If you need split files, verify the complete current set upstream. One fragment is not the whole list.

The raw text format keeps delivery simple. Mirrors improve availability, but copies of the same dataset are still the same intelligence source. More download locations do not mean more independent observations.

Where Data-Shield fits into SysWarden.

In SysWarden, Data-Shield supplies reputation data to host protection. The published downloader validates feed content and checks agreement across distinct HTTPS origins before publication. I treat that delivery check separately from the judgment that an address belongs in a blocklist.

I use the documented SysWarden workflow to manage its feeds and firewall state. Adding a second homemade updater beside it can create competing writers and confusing recovery. After configuration, I check the actual downloaded data, update status and intended traffic, including legitimate access.

Your platform can use the same idea.

Data-Shield is usable beyond SysWarden. The integration point is the platform's supported IP-list mechanism, followed by an explicit policy decision. These documented mechanisms are useful starting points, not a claim that I have certified every appliance or firmware version.

On OPNsense, a URL Table alias can fetch an address list at a chosen interval. I would use that alias in a deliberately scoped firewall rule and inspect the loaded table. Creating an alias alone does not establish a blocking policy.

FortiOS documents IP address external feeds for use in firewall policies. I would check the installed version, model limits, refresh behavior and source-versus-destination placement before enabling enforcement.

On Linux, nftables named sets can hold IPv4 addresses for rule lookups. A raw feed still needs a validated import process. It is data, not a ready-to-execute firewall script. I would never pipe a remote list straight into a privileged shell.

Make the first deployment reversible.

I start on a recoverable test system, preserve independent administrator access and identify the traffic that must keep working. Then I inspect the feed, test a limited rule and compare expected blocks with legitimate connections. A successful download is only the beginning of that check.

I also define what happens when an update fails: keep a previously validated snapshot where supported, record its age and alert on repeated failures. An empty response must not quietly replace working protection. Local exceptions need a reason, an owner and a review date.

Keep the limits in view.

An IPv4 reputation list cannot cover IPv6, identify every attacker or prevent attacks from new addresses. Shared hosting and reassigned addresses can also make yesterday's signal misleading. I keep patching, authentication, application security and monitoring in the picture, and I investigate false positives rather than treating the feed as unquestionable.

For feedback, I ask for the feed name, observation time and a description of the unexpected block. I keep credentials, customer data and internal network details out of public reports. A reproducible case helps me review the signal and improve the feed without exposing anyone.