Guest

Preview Tool

Cisco Bug: CSCtb01537 - CPPr: Telnet port not closed when transport input none is configured

Last Modified

May 31, 2018

Products (1)

  • Cisco IOS

Known Affected Releases

12.4(24)T1

Description (partial)

Symptom:

When telnet service is disabled via "transport input none" configured under the
vty lines, the TCP port 23 still shows up in LISTEN state in show control-plane
host open-ports output:

Router#show control-plane host open-ports 
Active internet connections (servers and established)
Prot               Local Address             Foreign Address                 
Service    State
 tcp                        *:22                         *:0              
SSH-Server   LISTEN
 tcp                        *:23                         *:0                  
Telnet   LISTEN


Conditions:

This affects all 12.4T IOS releases supporting Control Plane Policing up to
12.4(24)T1. Affects 15.2(4)M1 as well.
Bug details contain sensitive information and therefore require a Cisco.com account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.