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New Member

Cat4006, Cat2950 Serious Problems


We are using two Cat4006 as central switches and Cat2950 switches on floors in our company. Floor switches connected to central switches over gbic modules. Our internal network is operating on 4 VLANs configured on each switch.

We have serious network problems these days for exampe complately network down. We're using "Solarwinds Network Management Tools" to monitor our servers and we are using "Symantec Ghost Multicast Server" to deploy Windows 2000 to clients. Another company manages our Cisco devices and they claimed that network problems caused by Solarwinds Network Management Tools and Symantec Ghost. They also claim that Solarwinds Network Management Tools are not compatible with Cisco devices and non-standart for Cisco. They claim same things for Symantec Ghost. And they advice us to remove these applications immadiately and not to use over the network again. We were using "Symantec Ghost Multicast Server" to deploy Windows 2000 to clients (1 or 2 at the same time) on one floor in same VLAN on same switch. (Cat 2950)

One of the error message from the switch log below;

C4K_EBM-4-HOSTFLAPPING: Host [mac_address of the host which Solarwinds tools or Symantec Ghost Multicast Server running] in vlan xx is flapping between port Po1 and port Gix/x

Is it possible Solarwinds Network Management Tools caused these problems?

Aren't Solarwinds Network Management Tools compatible with Cisco devices?

Is it possible Symantec Ghost caused these problems?

We would be grateful If anyone would clarify us on this case.

Thank you,

Cisco Employee

Re: Cat4006, Cat2950 Serious Problems

Is your spanning tree topology stable? It normally indicates a STP loop

Also have you disabled IGMP snooping?

Cisco Employee

Re: Cat4006, Cat2950 Serious Problems


The host mac address flapping , the mac is learning from two ports in the same vlans. which is indication of the loop or mishaving of some application or the port. do you have any briding on any port channel interface.

Also what software version you are using on the switch and the l3 blade

Re: Cat4006, Cat2950 Serious Problems

Be careful with the Ghost application.

I've had a big trouble with it in my network. Until the newest version it was using multicasts to deliver Windows images to clients (even in the case of sending an image to ONE PC) and my network was flooded with multicast.

So it was necessary to configure IGMP and CGMP on my switches and one PIM interface on my router. (I've described my solution on this forum already if you are interested in detailes.)

So I recommend you to check multicast flows in your network at the time when Ghost server is sending images to clients.



New Member

Re: Cat4006, Cat2950 Serious Problems

Hi there.

I'm suggesting that you do the following:

1. Setup a log server. You can obtain a free log server at Setup your C4K and C2900 switches to log to this log server. Do NOT run both mentioned applications and see what the logs say. If you DON"T run the applications and the messages keep appearing then you might have an unstable STP instance/loop in your network or it might be that you have a dual interface NIC installed on a PC and this NIC is running in Team/EtherChannel mode.

2. If the messages do NOT appear in step 1 then start running the applications and again watch the logs and see what the switches say.

Let me know how you go at

New Member

Re: Cat4006, Cat2950 Serious Problems

I have customer has exact same LAN infrastructure setup, two 4006 layers switch as core and 2950 switches as closet switches. The network was working great for 6 monthes, until one day they used Ghost Mulitcast server to roll out Window 2000 professional workstation, the whole network experienced slow down and user TCP session drops. the 2950 were running

V12.1(9) EA1. I was being told this code has bug for support Multicast traffic, the lastest code 12.1.12c has fix it.

New Member

Re: Cat4006, Cat2950 Serious Problems

I don't know about Solarwinds Network Managements Tools compatibility, however I do know that Symantec Ghost 6.5 & 7 can bring your network to a crawl if you don't have your router and switches configured properly.

Take a look at your routers and make sure you have the following enabled on you 4006.

ip multicast routing

ip pim sparse-mode or ip pim dense-mode ( This depends on your network layout).

ip cgmp

Take a look at your cisco WS-C2950G-48-EI, make sure you have your switch / vlans setup for igmp


IGMP snooping is globally enabled

IGMP snooping is enabled on this Vlan

IGMP snooping immediate-leave is disabled on this Vlan

IGMP snooping mrouter learn mode is pim-dvmrp on this Vlan

IGMP snooping is running in IGMP_ONLY mode on this Vlan )

New Member

Re: Cat4006, Cat2950 Serious Problems


Please check the multicast transfer rate for the 2950, it much less than the Cat 4000. Test your application ones on a VLAN how exist only on the both 4000 include server and user pc. If the configs are well it will work well.