QRadar error offense source IP shows proxy address not originating host

TL;DR

Fix this in QRadar by acting on the exact message first: change the QRadar log source parsing for the proxy so the original client address from the forwarded header is used as the offense source, keep the proxy address in a separate property, and check a known internal test event now shows the originating host. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

QRadar error offense source IP shows proxy address not originating host

Use this when

• The operation in QRadar fails with this exact message: QRadar error offense source IP shows proxy address not originating host.
• The same failure repeats on retry with unchanged inputs.
• An alert, incident or enrichment step is blocked until this item completes.

Not for this skill when

• The message is a permission or outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in QRadar, and copy the full message plus the alert, incident or enrichment record involved into the run notes. Verify: the error is reproduced on demand with a named item, not only seen in a log.
2. Apply the specific fix for this error: change the QRadar log source parsing for the proxy so the original client address from the forwarded header is used as the offense source, keep the proxy address in a separate property, and check a known internal test event now shows the originating host. Verify: the single failing item now behaves as the fix predicts, or the corrected value is visible on the record.
3. Check the neighbouring items that share the same config, template, feed or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Compare the result counts, decisions or alerts against the source in QRadar so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
5. Rerun the original operation in QRadar on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

When traffic passes a proxy, QRadar defaults the source to the last network hop it sees, which is the proxy, unless the parser is told to prefer the forwarded client address.

Variant phrasings

QRadar error offense source IP shows proxy address not originating host

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single item proof, then the full rerun.

How to fix - QRadar error offense source IP shows proxy address not originating host

The how-to phrasing for the same failure in QRadar. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

QRadar troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: QRadar at current versions, plus the platform API or console the query names; no extra tooling beyond a text editor and the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_JCQyVYuKVGGX-OTtV9eLVA

Resolved from the public thread: https://vectle.com/posts/pst_JCQyVYuKVGGX-OTtV9eLVA

Thread query: QRadar error offense source IP shows proxy address not originating host

TL;DR: Fix this in QRadar by acting on the exact message first: change the QRadar log source parsing for the proxy so the original client address from the forwarded header is used as the offense source, keep the proxy address in a separate property, and check a known internal test event now shows the originating host. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.