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Cisco Bug: CSCub04965 - TCP Session hung causing Packet loss

Last Modified

Dec 13, 2019

Products (123)

  • Cisco IOS
  • Cisco Catalyst 3560E-48PD-SF Switch
  • Cisco Catalyst 3560G-48PS Switch
  • Cisco Catalyst 3560E-12D-E Switch
  • Cisco ME 3400EG-2CS-A Switch
  • Cisco Catalyst 2960-48TT-S Switch
  • Cisco ME 3400-24TS-A Switch
  • Cisco Catalyst 2960-24TC-L Switch
  • Cisco Catalyst 3560X-48P-S Switch
  • Cisco Catalyst 3750V2-24PS Switch
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Known Affected Releases

12.2(33)SCC3 12.2(33)SRD 12.2(50)SE5 12.2(55)SE n/a

Description (partial)

Symptom: Multiple symptoms may occur including:

- Multiple sessions established to TACACS+ server which never clear are seen in the output of <CmdBold>show tcp brief<noCmdBold>.
- Pings to the loopback address from directly connected equipment suffers 
packet loss.
- Traffic and pings through the switch suffers packet loss.
- CPU utilization remained stable and below 10% when the issue was occurring, the interface counters were not reporting any errors or drops.
- TACACS+ authentication errors, authorization errors, or accounting errors.
- SSH/TELNET via VTY not accessible.
- If condition exists for a period of time the switch may stop passing traffic.
Conditions: The symptom is observed when the device is configured with TACACS+. It is seen mostly on Cisco 3750/3760 switches, but has been observed on Cisco 6500 switches.

Related Community Discussions

<key>CSCub04965</key> - TCP Session hung causing Packet loss
FYI - We have experienced this problem in the 2951 router running 15.1(4) IOS.
Latest activity: Jan 15, 2014
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Bug Details Include

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  • Status
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