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problems with a HP4108 GL switch

Occasional Visitor

problems with a HP4108 GL switch


I have some problems with one of my HP4108 switch. It seems that it work as a hub !!! unicats traffic that i'm not the destination are sending to my network card !
I don't understand.
Can you help me ? is it possible to turn a HP4108 switch into a hub operating mode ?
I have the last firmware.
Ron Kinner
Honored Contributor

Re: problems with a HP4108 GL switch

Most switches have the ability to select one port as a monitor port and to send copies of traffic on other ports to the monitor port. That would make it appear that it was acting as a hub but I'm not sure the port would be two way. Could be you could only listen.

Some switches let you statically assign a MAC to a port. The MAC stays assigned to the port after the PC has been removed. Could be you are seeing something like that but the extra traffic would be limited to only certain MACs.

If it thought your port were a trunk it might try to send all kinds of stuff to you.

Finally and most likely, if the switch receives a message for a MAC address and it doesn't know where the MAC is I presume it would act like a bridge and flood the message out every port to see if it would get a response. This could happen if the MAC table on the switch expires before the ARP table on a PC or router or if a static ARP table entry has been added to the arp table of a pc or router. Assuming something responds to the flood you shouldn't see any more traffic to that MAC until the table expires again.

What are you using to monitor the traffic with? Can you move to a different port to see if it has any effect?

Frequent Advisor

Re: problems with a HP4108 GL switch

I'm experiencing the same problem with a 4108gl.
I have heard some ports of the switch with Sniffer Pro (NAI) and it happens in all the ports. The monitoring port is disabled.
Have you found a solution to the problem?
Thank you.
Arimo Laine_2
Valued Contributor

Re: problems with a HP4108 GL switch


Turning a switch to "hub mode" is not possible at all.

Is the device flooding all unicast traffic, or is this a question of some specific application, is all this traffic directed to same destination?

Romeo Chance
Occasional Advisor

Re: problems with a HP4108 GL switch


I had the same problem (unicast flood)
on my Procurve 4000M switch.

After months of battling, i found that
changing the MAC-AGE time on the switch
from the default setting of 5mins to 30mins
solved the problem.

If you havent solved it, try that and
it should stop the unicast flood.

Trusted Contributor

Re: problems with a HP4108 GL switch

The october firmware was buggy. HP solved many issues in 16th December 2002 with G.07.21, which you can find at http://www.hp.com/rnd/software/switches.htm