switch or Hub ?

[jmarwan]

I have connected my switch catalyst 2900XL (with the latest release) to backbone switch (cisco 4500).
using a sniffer protocol (Ethreal) .i can receive unicast packets that have source and destination mac-address different of mine.
i have tried to block flood unicast & multicast traffic.
i still receive the same traffic.
i ask it'is normal for a switch (L2) to receive such traffic?

 

[RookThis]

The only time a switch floods out every port on a particular broadcast doman is when it does not have destination mac address in it's CAM table. You need to try to identify what device is causing this to happen. A few weeks ago I had a similar problem, it turned out to be a couple of servers that were not configured properly.

Hope this helps.

 

[darbyweaver]

OK, this is a tough one but it is a common issue it seems...

1. Remember the switch is a smarter bridge.

2. Remember ARP?

3. If a device does not know what to do with a packet it will arp?

4. Check those packets and see if they are not a lot of ARPs.

5. As for the multicast packets, do you have multicast enabled? Verify. Also recall CGMP may be enabled as well by default.

Good Luck...

Darby Weaver

 

[nape]

RookThis,

What was configured improperly on your server(s) to cause the flooding?

And are you still seeing the flooding behaviour?

Thanks