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RADIUS attribute 30 · type string

Called-Station-Id

Called-Station-Id (attribute 30) identifies what the device connected to. On Wi-Fi it's the AP's MAC address plus the SSID, so you can write per-SSID RADIUS policy.

Also searched as: AP MAC and SSID attribute, Called-Station-ID. Defined in RFC 2865.

What it means

Called-Station-Id names the NAS-side endpoint. On wireless it typically encodes the access point's BSSID followed by ":SSID" — which means you can read the SSID straight out of the attribute and apply different rules to, say, a staff SSID versus a guest SSID from the same server. On wired it's the switch port MAC.

How it's used

Split on the ":" to recover the SSID for policy matching. Pair it with Calling-Station-Id (the client MAC) when correlating a session end-to-end.

Common gotchas

  • The BSSID/SSID delimiter and MAC format vary by vendor; don't hard-code an exact string when a "SSID ends the value after the last colon" match is more portable.

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Related

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