11-04-2008 11:44 PM - edited 03-04-2019 12:11 AM
Hi;
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.
11-04-2008 11:49 PM
we had the same problem.
our cisco partner said this a bug and you should upgrade software.
11-04-2008 11:52 PM
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
Pad7_Fiber_Switch#
11-05-2008 12:32 AM
Hi,
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.
BR,
Milan
11-05-2008 07:22 AM
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;
regards
11-05-2008 07:41 AM
Hi,
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.
BR,
Milan
11-05-2008 08:20 AM
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 ?
11-05-2008 08:36 AM
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.
BR,
Milan
11-05-2008 08:21 PM
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
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: