Storm control level command

[s.gilbrook]

Dear all,

We have been experiencing some issues with high levels of Broadcasts which seem to be effecting the whole of the LAN (multiple routed VLAN's).

I am thinking of enabling the stome-control feature on all GB uplinks we have from our wiring closet 2950G's (approx 24 1Gb uplinks to 2 x 4507's), but cannot get my head around what rising and falling suppressions levels to set the interfaces at.

I wondered if there were some 'default' levels that could be set on the interfaces.

Any advice would be greatly appreciated.

Thanks.

[sagar.joshi]

Hi,

Upgrade latest IOS on both the Switches.

Switch 2950 Commands :

storm-control broadcast level 80.00

storm-control multicast level 80.00

Commands on 4507 :

set port broadcast Module/Port 50.00% multicast disable unicast disable

Regards,

Sagar Joshi.

[milan.kulik]

Hi,

IMHO, if your network suffers with 80% of broadcasts, it would be in a really bad trouble.

The CCDA course book states broadcasts/multicasts should not exceed 20% of traffic on a healthy Ethernet segment.

There are also following default values on Cat3500XL FastEthernet interfaces:

500 pps broadcast rising threshold

250 pps broadcast falling threshold

For multicasts the default values are 2500/1200 pps.

I'm using

storm-control broadcast level 5.00 3.00

storm-control multicast level 5.00 3.00

on my access-level 2950s.

Generally, the lower level you set on your interfaces, the sooner you get an alarm when something wrong happens.

I'm using even 1% on my server farm switch.

On the other hand, if you set the level too low, you'll get false positive alarms.

So it requires some testing to tune the level correctly for your network.

Regards,

Milan

[mohamed-khadr]

Setting storm control filters are the not the answer. You need to find what is generating either b'cast or m'cast on the network. could it be: 1) bad NIC on a PC or server 2)R u running novell IPX,it generate huge b'cast>> sap & rip<< 3)Is ur network segmented, if not config VLANs to isolate the b'cast to each b'cast domain.4) consider using a one arm router to route between vlans and segment ur network.

HTH.

mohAmed khAdr