Switch stop responding management IP.

Unanswered Question
May 2nd, 2010
User Badges:

Hi, We had for a long time four stacks of 3550 and 3560 connected by Optic Fiber to a Layer 3 swtich 6500.Today we have chaged those stack by 3750 switches and the problem go on. This is the problem: Management IP of Vlan1 stop responding by a short time, meanwile, the PC's conected to those stacks go on working and all the stacks are shown by CDP protocol in the 6500. We have no events, no error on fiber, nothing at all. We have no control what are conected to those stack, the most are Dell computers but there is no control which device al conected to us stacks.

The management IP belong to the same subnet in a lonely vlan with all devices, PC's, printers, etc-

Any idea?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Reza Sharifi Sun, 05/02/2010 - 13:51
User Badges:
  • Super Bronze, 10000 points or more
  • Cisco Designated VIP,

    2017 LAN


You should NOT mix the production vlan with management vlan.  You want to be able to get to the devices in case some thing goes wrong with the production vlan.  You should never use vlan 1 for production or management.  I suggest making the separation and see if the problem still exist



Leo Laohoo Sun, 05/02/2010 - 14:09
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    The Hall of Fame designation is a lifetime achievement award based on significant overall achievements in the community. 

  • Cisco Designated VIP,

    2017 LAN, Wireless

Do you have any logs to show something suspicious?

rictorres333 Sun, 05/02/2010 - 22:54
User Badges:

Ok, nothing suspicius. The Vlan1 was configured by a company decission, It can`t be changed, most of building of my company have this Vlan in use, I said that is no a good idea but, when i began working here, that it is already configured and there is no posiblity of change. No problem is present in another network in this company using Vlan1.

In another hand,  sometime, i thought in a Denied Of Service attack, I have changed the management IP of the stacks and began doing the same problem with the new IP.

I think that the problem can be the layer 3 in 6500, but i don't understand why others device are not affected. All in the this network seems to work correctly.

rahurao Mon, 05/03/2010 - 03:45
User Badges:

HI Ric,

Can you send us the "show proc cpu when the issue happens and also the show proc cou history from the switch.

You can do a console session to check the same.



rictorres333 Mon, 05/03/2010 - 04:11
User Badges:

Hi, there's no posibility, I have all those switch remotely.  Only the last one "history" after recover the fail. I'll be waiting for the next fail to run the command.

rictorres333 Mon, 05/03/2010 - 05:47
User Badges:

This is the result, after  a recovey a recent fail:

On 6500 switch this is the result:


This Discussion