iSCSI portal access restriction

Ayu Lestari 40 Reputation points
2026-09-01T06:32:36.2433333+00:00

Hi

May I know if someone here has faced a situation where an iSCSI SAN target server hits 100% CPU usage because misconfigured third‑party scanners keep sending unauthenticated iSCSI SendTargets requests ? I’m trying to figure out how to properly restrict iSCSI portal access using IPSec policies and initiator ACLs to stop those requests. I’m not sure if the issue is mainly from the scanner side or something misconfigured on the target server. Thanks

Windows for business | Windows 365 Business
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  1. HLBui 11,495 Reputation points Independent Advisor
    2026-09-01T07:26:17.35+00:00

    Hi Ayu Lestari •

    Those unauthenticated SendTargets requests can hammer the CPU hard. The clean way to stop them is to combine IPSec policies with initiator ACLs. IPSec lets you block or allow traffic only from trusted IP ranges, so random scanners won’t even reach the iSCSI service. Then ACLs make sure only initiators with the right IQNs can log in or discover targets. If you want extra safety, enable CHAP authentication for discovery so anything unauthenticated gets dropped immediately.

    In short: lock down the portal with IPSec, whitelist initiators with ACLs, and enforce authentication. That combo usually takes care of the CPU spike issue. If this explanation helps stabilize your environment,

    If everything is okay, don't forget to share your experience with the issue by "Accept answer". If you need more information, feel free to leave a message. We are happy to help!

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