Performance degrade -

Unanswered Question
Nov 12th, 2009


on 4506 a backup VLAN is created to take all Windows server backup. Each Server has Two NIC 10/100/100[ one used for backup ]

Performance on Network is slow, its a isolated VLAN it shouldn't impact LAN.

So far couldn't identify the cause.

Earlier the backup was running on Isolated switch.

I have this problem too.
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Jon Marshall Thu, 11/12/2009 - 07:39


Not really enough information but as a general point it is worth noting that even though the vlan is isolated on the 4506 it is still using the same switch fabric as all the other vlans and it may be that the backup traffic is impacting on the LAN traffic.

You could look to use QOS to prioritize the LAN traffic during the day but personally i would look to use dedicated separate switches for the backup LAN, as you were originally.


hobbe Thu, 11/12/2009 - 08:12

even though a vlan is separated "virtually" it still uses the same hardware and the hardware is finite ie you can only load it "so much".

I agree with jon. run it on separate physical hardware.

If you do not want to do that, start looking at CPU, memmory and traffic counters to determine what you can expect in terms of throughput.

ie how much load it is doing before the backup then add the backups traffic load.

if you have a management solution look in there to see if you can determine what is hitting the roof.

if you have the money go to and buy the engineer toolkit that will helpt you alot. If you dont want to buy it, get the trial and atleast it will help you this time.


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