Event 6274 · NPS discarded the request

NPS Event 6274 — 'discarded the request' is not a reject (and why that matters)

The event text: “Network Policy Server discarded the request for a user.”

What it actually means: NPS didn’t say no — it said nothing. A 6273 (denied) means the request was evaluated and rejected: the NAS gets an Access-Reject, the client fails fast. A 6274 (discarded) means NPS threw the packet away without answering at all: the NAS sees a timeout, retries, and may fail over to a secondary RADIUS server. If users report “Wi-Fi takes forever and then fails” rather than failing instantly, you’re in discard territory.

The discard reasons cluster into three families:

1. The packet couldn’t be trusted

The most common discard: the message failed verification, so answering would be unsafe. The Reason Code / Reason line in the 6274 event says the message was malformed or its signature/authenticator couldn’t be verified. This is almost always the shared secret disagreeing between the NAS and the NPS RADIUS Client entry — the discard-flavored sibling of Reason Code 262.

Check: re-enter the shared secret on both sides; confirm the request is matching the RADIUS Client entry you think it is (source IP in the event vs. your entries).

2. The packet was malformed or unsupported

Vendor quirks: NAS firmware sending malformed attributes, unsupported RADIUS extensions, or (rarely) genuinely corrupted UDP. If the secrets check out, capture a failing exchange and compare it with a working NAS of the same model — firmware upgrades on the NAS fix a surprising share of these.

3. Server-side trouble answering at all

If discards appear for all clients at once, look at the NPS server rather than the packets:

• NPS not registered in AD — it can’t read dial-in properties, so requests can’t be processed. Fix: right-click NPS (top node in the console) → Register server in Active Directory (adds the server to the RAS and IAS Servers group).
• Accounting failure discards — if NPS is configured to log accounting to a SQL server or a full disk and “discard connection requests if logging fails” is enabled, an accounting outage silently discards authentications. Check Accounting configuration and the free space/SQL connectivity.
• Event log neighbors (event 13, 4402 in the System/NPS logs) often name the server-side cause precisely.

Triage in one line

One NAS discarding → shared secret or that NAS’s firmware. Everything discarding → NPS registration or accounting/logging backend. Instant failures instead of slow ones → you’re actually looking at 6273, different playbook.