When talked with users user says their is no extar ordinary increase in uploading or downloading. My ISP say there must be some
virus/worm in the network.
Sounds like you are one of the sites flooding people with icmp :(
Try this: tcpdump -v -nn icmp
Look at the source IP's of the echo-request packets and fix your systems.
If that does not help, try a tool like ntop or iptraf which will tell you who is generating all the traffic.
HTH, C
