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RADIUS

The RADIUS client lives in the radius view and applies live on commit — servers are re-resolved and scalars updated in place. The one exception is coa-port, whose listener re-binds only at boot.

Server list and failover

The server list is index-addressable; insert, delete and move reorder failover priority. Default ports are 1812 for auth and 1813 for accounting.

cli
system-view
radius server add 198.51.100.10 secret <shared-secret>
radius nas-id netvyn-bng-01
radius timeout 2
radius retries 3
radius interim-interval 300
commit
show radius statistics

Message-Authenticator

Attribute 80 is an HMAC-MD5 signature over the whole packet keyed with the shared secret. Keep it on: RADIUS/UDP’s Response Authenticator is raw MD5 and chosen-prefix collidable, so an on-path attacker can forge an Access-Accept out of an Access-Reject (CVE-2024-3596). HMAC-MD5 is unaffected. Modern servers increasingly require attribute 80 and silently drop requests without it, which presents as a total authentication outage rather than a protocol error.

cli
radius message-authenticator on        # off | on (default) | require
show radius statistics                 # watch bad-msg-authent.

CoA and Disconnect

Change-of-Authorization per RFC 5176 pushes plan changes and disconnects to a live session without teardown, and the QoS engine rebinds the shaper in place. Only User-Password, Tunnel-Password and the MS-MPPE keys are obfuscated in RADIUS — everything else, including all Netvyn VSAs, is plaintext on the wire.