> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/deploy/host-n8n/configure-n8n/basic-configuration/use-environment-variables/security.md).

# Configure security environment variables in Duaer

In Duaer, security switches such as SSRF are configured with environment variables. From v3 the default blocked IP ranges are wider, and the check links here.
## The default SSRF list

With SSRF protection on and still using the built-in default list, v3 blocks more shared address space and IPv6 transition ranges. Addresses that used to look reachable on a private network may start failing. The instance check links here.

If you must reach a range, configure allow rules or adjust the list from the security docs. Do not only turn the whole protection off. Policy entry points are also under [security policies](/deploy/host-n8n/configure-n8n/security/manage-security-policies.md).
## Questions

### Did Duaer v3 make the default SSRF blocks stricter?

Yes. The built-in default list blocks more shared address space and IPv6 transition ranges. With SSRF protection on and still on the default list, requests to those hosts start failing.