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Cisco Bug: CSCun71347 - 3850 Crash in "CEF: IPv4" Process While Processing ARP Throttle Elements

Last Modified

Aug 20, 2020

Products (1)

  • Cisco IOS

Known Affected Releases


Description (partial)

3850/3650 switch crashes with:

Exception to IOS:
IOS Thread backtrace:
IOSD-EXT-SIGNAL: Illegal instruction(4), Process = CEF: IPv4 process
-Traceback= XXXXXXXX ...

It is not directly related to box configuration, network topology, etc.
The crash may occur during normal ARP adjacency handling (addition or removal of adjacencies) as a result of an internal software issue.

Related Community Discussions

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Release 3.6.6.x Beta (15.2(2)E6) We are pleased to announce the availability of 3.6 MR6 beta (future 3.6.6). If you are interested in participating, please send email to, please include information on the intended use and beta test plans/configurations/topology details Resolved Caveats: 03.06.06.E.713 CSCvb29204 BenignCertain on IOS and IOS-XE CSCuu05714 Constant high cpu due to SNMP ENGINE when pooling MIB lldpXMedMIB CSCuz57493 High CPU observed in punjectrx fed-ots-main ...
Latest activity: Jul 21, 2017
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