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New Member

Cisco Catalyst 3500 Cold and Warm reboot


i have Cisco switch network and am having an issue. Due to no visible reason a few of my switches stop responding to ping/telnet/cdp etc but they still pass layer 2 and I can ping devices beyond the affected switch/switches. Its happening only on the 3500 series switches. When the problem happens all the lights on the switch turn solid green and stay lit.


Re: Cisco Catalyst 3500 Cold and Warm reboot

we had the same problem.

our cisco partner said this a bug and you should upgrade software.

New Member

Re: Cisco Catalyst 3500 Cold and Warm reboot

I think were on the latest firmware here..

Here is the show version

Did you end up resolving ?

Pad7_Fiber_Switch#show ver

Cisco Internetwork Operating System Software

IOS (tm) C3500XL Software (C3500XL-C3H2S-M), Version 12.0(5)WC17, RELEASE SOFTWA

RE (fc1)

Copyright (c) 1986-2007 by cisco Systems, Inc.

Compiled Tue 13-Feb-07 15:04 by antonino

Image text-base: 0x00003000, data-base: 0x00352924

ROM: Bootstrap program is C3500XL boot loader

Pad7_Fiber_Switch uptime is 1 hour, 14 minutes

System returned to ROM by reload

System image file is "flash:c3500xl-c3h2s-mz.120-5.WC17.bin"

cisco WS-C3508G-XL (PowerPC403) processor (revision 0x01) with 8192K/1024K bytes

of memory.

Processor board ID FAA0447H0Q6, with hardware revision 0x01

Last reset from warm-reset

Processor is running Enterprise Edition Software

Cluster command switch capable

Cluster member switch capable

8 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: 00:04:4D:09:3F:C0

Motherboard assembly number: 73-3985-11

Power supply part number: 34-1000-01

Motherboard serial number: FAA04459XRC

Power supply serial number: APQ043900BG

Model revision number: R0

Motherboard revision number: B0

Model number: WS-C3508G-XL-EN

System serial number: FAA0447H0Q6

Configuration register is 0xF


Re: Cisco Catalyst 3500 Cold and Warm reboot


when your switch freezes, are you able to connect via console?

If yes, what does sh proc cpu say?

Isn't the CPU overloaded?

How does your management VLAN look like?

Isn't it the same as the VLAN to which user PCs are connected?

If yes, the switches could be overloaded by broadcast or multicast storm, e.g.



New Member

Re: Cisco Catalyst 3500 Cold and Warm reboot

Hi Milan;

Thanks for your kind reply;

i have checked and confirmed that my switch is not responding even via console. this behavior is common with my most of switches. could you please advise me any security measures which i should adopt/implement? for your information, i have only 1 default VLAN for all users and comouters.

i am waiting for your reply;


Re: Cisco Catalyst 3500 Cold and Warm reboot


I'd guess:

If everything is on one VLAN, your switch CPU might be overloaded by some broadcast or multicast storm.

So I'd try to configure another VLAN and make it a management VLAN for your switches.

Configuring broadcast and multicast storm control on your ports is another good idea.

You could also connect a PC with Wireshark or another data analyser installed and try to capture traffic in your LAN at the moment your switches freeze.



New Member

Re: Cisco Catalyst 3500 Cold and Warm reboot

This will be on a 3500XL switch so the broadcast suppression will be in pps so i'm starting with a rising threshol of 5000 and a falling threshold of 2500.

Do you have any idea what broadcast packet rate would result in the switch being overwhlemed ?

Re: Cisco Catalyst 3500 Cold and Warm reboot

No idea.

I was facing a multicast storm with 3500XLs only once, 5 years ago. If I remember correctly, the values we were using were about 1200 for rising and 500 for falling threshold.

As broadcasts are more common within LANs, you should start with hihger numbers probably and observer in the beginning.




Re: Cisco Catalyst 3500 Cold and Warm reboot

yes this version is affected by:CSCdw59208 Bug .

CAT 3500xl CPU12 buffers 0 in free list causes telnet/ping loss

0 in free list on CPU 12 buffers causes telnet / ping

session loss to the management interface.

L2 traffic between physical interfaces going through

the box is not affected by this.

Status :Fixed (Verified)

Severity :3 - moderate

1st Found-In 12.0(5)WC2

Fixed-In 12.0(5)WC5