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Beginner

Cisco CATALYST 6506: Out of telnet processes.

Hello,
Can someone help me on the case below?

We have a Cisco CATALYST 6506, CatOS based, with the following config:

Switch 6506 (enable) sh ver
WS-C6506-E Software, Version NmpSW: 8.4(5)
System Bootstrap Version: 12.2
System Boot Image File is 'bootdisk:cat6000-sup32pfc3k8.8-4-5.bin'

When we tried to connect remotely, we get the error: "Out of telnet processes.  Try later."

After troubleshooting the device at local console session, I see it has several “telnet” process running

Switch 6506  (enable) sh user
Id  Session  User                             Location
--- -------- -------------------------------- -------------------------
1    telnet  user1                          server1.com
2    telnet  user2                          l325.com
3    telnet  user3                           1.1.1.1
4    telnet  user4                           1.1.1.1
5    telnet  user2                           l325.com
6    telnet  user2                            l325.com
7    telnet  user2                           l325.com
8    telnet  user2                            l325.com
9    telnet  user2                           l325.com
10   telnet  user2                        l325.com
11   telnet  user2                         l325.com
12   telnet  user2                         l325.com

After trying to disconnect, for example user2: I got the error:

Switch 6506 (enable) disconnect 2
Telnet session from l325.com is executing a command.Retry later

Same output if I tried to disconnect any user2 session.

According with CatOS version I cannot configure ssh instead of telnet.

Below, sh proc including telnet processes:
Switch 6506 (enable) sh proc | inc telnet
48  3  st 0x206ffdf8 247         4f3      2000    2460/12288 -2  telnetd
177 3  rd 0x20cdd8dc 1126846073  657725ef 5000    3996/16384 747728660 telnet177
178 3  rd 0x20cdd8dc 1088498686  59578484 3000    3100/16384 745539732 telnet178
179 3  rd 0x20cdd8dc 1031563103  83a93355 3000    3100/16384 754568468 telnet179
180 3  rd 0x20cdd8dc 1008790120  8278a2e5 3000    3100/16384 752170388 telnet180
181 3  rd 0x20cdd8dc 724490720   98a5eea9 4000    3228/16384 752029844 telnet181
182 3  yl 0x20cdd8dc 720835578   96a10af4 4000    2964/16384 744687380 telnet182
183 3  rd 0x20cdd8dc 720538797   93d5fc98 4000    3100/16384 746550292 telnet183
184 3  yl 0x20cdd8dc 707954600   8d042511 4000    3052/16384 749388692 telnet184
185 3  rd 0x20cdd8dc 609013146   5d66a5c  3000    3100/16384 754052500 telnet185
186 3  rd 0x20cdd8dc 592388756   5f71137c 3000    3100/16384 745232404 telnet186
187 3  rd 0x20cdd8dc 372560873   aac67097 4000    2964/16384 746506132 telnet187
188 3  rd 0x20cdd8dc 365793051   72bab221 3000    3100/16384 747102996 telnet188

There is any way to force "kill" or disconnect telnet sessions/processes on the switch?

Thanks in advice,

Jefry

Everyone's tags (4)
8 REPLIES 8
Rising star

Cisco CATALYST 6506: Out of telnet processes.

Hi,

Can you try the below.

router#clear line vty (line number)

Thanks

Beginner

Cisco CATALYST 6506: Out of telnet processes.

Yes, I tried buy CLI didn't accept this command.

Rising star

Cisco CATALYST 6506: Out of telnet processes.

Hi,

Can u paste wht u have typed.

it should be like

router#clear line vty 1-10

Thanks

Cisco Employee

Cisco CATALYST 6506: Out of telnet processes.

Hi Jefry,

In order to resolve this issue, issue the show users command to check how many Telnet sessions have opened for the switch. Disconnect the Telnet sessions opened by the remote device with the disconnect ip_address command


Give command "sh user"  this will display telnet sessions along with the ip address
location from which session is open, note down this ip address and

Give command "disconnect <ip-address>"  this will disconnect those sessions which
are taking unnecessary memory.

Regards,

Aru

Regards, Aru *** Please rate if the post useful ***
Beginner

Cisco CATALYST 6506: Out of telnet processes.

I'll try with router#clear line vty 1-10

Also, I tried:

Switch 6506 (enable) disconnect 2

Telnet session from l325.com is executing a command.Retry later

Where "2" was session ID

I didn't see the option: "disconnect "

Cisco Employee

Cisco CATALYST 6506: Out of telnet processes.

Hi Jefry,

When you check the show users, you are seeing below result,

Switch 6506  (enable) sh user
Id  Session  User                             Location
--- -------- -------------------------------- -------------------------
1    telnet  user1                          server1.com
2    telnet  user2                          l325.com
3    telnet  user3                           1.1.1.1
4    telnet  user4                           1.1.1.1
5    telnet  user2                           l325.com
6    telnet  user2                            l325.com
7    telnet  user2                           l325.com
8    telnet  user2                            l325.com
9    telnet  user2                           l325.com
10   telnet  user2                        l325.com
11   telnet  user2                         l325.com
12   telnet  user2                         l325.com

Need to find the IP address of I325.com and sever1.com, then try to execute like below,

#disconnect 1.1.1.1

#disconnect

#disconnect

I have seen some previous cases and this command helps to clear the telnet session.

Refer:

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a008014f550.shtml

Regards,

Aru

Regards, Aru *** Please rate if the post useful ***
Beginner

Cisco CATALYST 6506: Out of telnet processes.

Hello,


I tried the commands above, without results:

Switch 6506 (enable) disconnect 18.18.18.18
Usage: disconnect

Switch 6506 (enable) disconnect 2
Telnet session from  l325.com  is executing a command.Retry later

Switch 6506 (enable) clear line vty 1-10
Unknown command "clear line". Use 'clear help' for more info.
Switch 6506 (enable) clear line ?
Unrecognized command!


Switch 6506 (enable) clear ?
kerberos                   Clear Kerberos configuration information
  key                        Clear config-key string
  l2protocol-tunnel          clear L2 Protocol Tunnel information
  lacp-channel               clear LACP statistical information
  lda                        Clear Local Director Accelerator Config
  localuser                  Clear localuser record
  log                        Clear log information
 
Trying with reset:


Switch 6506 (enable) reset ?
  at                         Reset at future time
  cancel                     Cancel schedule reset
  in                         Reset in future time
  mindown                    Reset With Minimum Downtime
  system                     Reset System
                        Reset Module
                   Reset Voice Port
                         Reset System

Trying with clear:


Switch 6506 (enable) clear p?
  pbf                        Clear PBF information

Image: System Boot Image File is 'bootdisk:cat6000-sup32pfc3k8.8-4-5.bin'

Any other idea? switch has several end user connections and trunk links, this is why I need to do all the necessary before reboot it.

Cisco Employee

Cisco CATALYST 6506: Out of telnet processes.

Hi Jefry,

The Catalyst operating system allows a limited number of processes based on the number of stacks available. When stacks are unavailable, this message is generated.

CatOS switch allows only a limited number of processes with a type 2 stack, for example, Console, snmpdm, VtpRx, THREAD, telnet145, in the system. The maximum number of processes with a type 2 stack is 13. Telnet or Secure Shell (SSH) is one of the processes which require a type 2 stack. When all type 2 stacks are used, any attempt to connect through Telnet results in this error message.

This possibly happened because the old Telnet or SSH sessions did not timeout on the switch and consume the process.


Resolution:
In order to resolve this issue, issue the show users command in order to check how many Telnet sessions have opened for the switch. Disconnect the telnet sessions opened by the remote device with the disconnect {ip_address} command

But we tried multiple options which didnt help us to clear the existing session.

  • I feel that the only way to recover the telnet resources is to reload the switch
  • I can see that there are many telent session originated by I325.com. What type of this device it is? is it possible to stop telnet access to the switch for some time and observe the performce
  • You could perform the reload as the last option

Regards,

Aru

Regards, Aru *** Please rate if the post useful ***
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