[c-nsp] Filtering TCP NULL packets

[Gideon Le Grange]

On 23 Jul 2007, at 4:19 PM, Jim Devane wrote:

> Hello,
>
>     I am seeing a large increase in TCP NULL packets over our  
> network. I
> am looking for suggestions on effective ways to block this traffic.
> I have considered ACL'ing something like this:
>
> ip access-list extended test
>  deny   tcp any any match-all -ack -fin -psh -rst -syn -urg
>  permit ip any any
>
> What other methods might be more effective?

What do you mean by null? Does the packet contain only TCP headers  
and no payload?

G