Fix SNMPv3 advance cached authoritative engineTime with the local clock#309
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n3-ruben-sanchez wants to merge 1 commit into
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Fix SNMPv3 advance cached authoritative engineTime with the local clock#309n3-ruben-sanchez wants to merge 1 commit into
n3-ruben-sanchez wants to merge 1 commit into
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The USM engineTime was frozen at the value learned during discovery and never advanced, so after ~150s of wall-clock drift the agent rejected requests with usmStatsNotInTimeWindows. The single per-request resync retry could not recover on agents with an erratic clock, leaving the session permanently broken until restart. Track the authoritative (engineBoots, engineTime) plus a monotonic timestamp when learned, and advance engineTime by the elapsed seconds on each outgoing v3 request (RFC 3414 section 2.3). Re-anchor from every authenticated message (Report and GetResponse), not just Reports, with a forward-only guard so reordered/delayed responses cannot rewind time. Handle the 31-bit engineTime rollover, and only anchor from authenticated sessions.
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The USM engineTime was frozen at the value learned during discovery and never advanced, so after ~150s of wall-clock drift the agent rejected requests with usmStatsNotInTimeWindows. The single per-request resync retry could not recover on agents with an erratic clock, leaving the session permanently broken until restart.
Track the authoritative (engineBoots, engineTime) plus a monotonic timestamp when learned, and advance engineTime by the elapsed seconds on each outgoing v3 request (RFC 3414 section 2.3). Re-anchor from every authenticated message (Report and GetResponse), not just Reports, with a forward-only guard so reordered/delayed responses cannot rewind time. Handle the 31-bit engineTime rollover, and only anchor from authenticated sessions.