C3550-12G and ESW-520-24

[stefan.gillich]

Hi

I'm using several Cisco Small Business ESW-520-24 switches connected to a C3550-12G switch.  The C3550 has configured 2 VLANs.  The ESW-520's are connected (Layer 2) using trunking to allow all 2 VLANs.  Connection between ESW-520 and C3550 works fine until the C3550 gets rebooted.  After reboot there is no communication between ESW-520 and C3550.  The LEDs at the C3550 ports are of while the LEDs at ESW-520s just looks normal.  Even the connection to the C3550 is looking normal (LED green and flashing like there is traffic).  However, communication is not possible.  Rebooting the ESW-520 switches solves the problem.  Any idea how to solve this issue?

C3550 is running IOS Version 12.2(40)SE (ip service edition)

ESW-520 is running software version 2.1.19 and boot version 1.0.0.04

Thanks for your support

Stefan

[andtoth]

Hi,

When did you first start observing this issue?

Is it a new setup or was it working before?

What has changed in the network or configuration when you have started to observe this?

Are you seeing the connectivity issue on all ESW-520-24 switches when the 3550-12G is rebooted?

Could you check the interface status on the 3550 connecting to these switches before and after the reload of the 3550?

Could you please share the configuration of the switches?

How are the switches connected? Which ports are they using for the connection?

Best regards,

Andras

[stefan.gillich]

Hi Andras

We started obsering this behaviour some month ago.  It wasn't running well from the beginning.  In the beginning, the ESW-520-24 lost communication to C3550 from time to time (several days communication was OK than it stoped).  After upgrading to the latest firmware version on ESW-520-24 the communication loss during normal operation is gone.  What left is the communication loss after rebooting C3550, what happens to all connected ESW-520-24.  If this happens rebooting the ESW520-24 is solving the problem.  Also "shut/no shut" of the corresponding interfaces on the C3550 solves the problem.

I will provide more information during the next days.  Right now I'm upgrading IOS version on C3550 to the lastest version c3550-ipservicesk9-tar.122-44.SE6.tar to check if something changes.

[andtoth]

Hi Stefan,

Thanks for your reply. Let me know if the upgrade solves the issue.

If you're still experiencing this problem after the upgrade, I'd be interested to see the output of the following commands in a working and a non-working scenario.

show arp

show mac address-table interface

show spanning-tree interface

show spanning-tree vlan detail

How do you see the connectivity issue?

Do you lose connection to the switch cli or you lose connection to devices connected on the ESW switch?

Are you routing with the 3550 or using it as a L2 switch?

Best regards,

Andras