I'm very sorry for repost this.

no manual entry for iftop-dump,and how does it to capture bandwidth information to a file?

I put this command direct: test@test:~/test/iftop$ sudo ./iftop-dump [sudo] password for test: interface: eth0 IP address is: 172.25.25.212 MAC address is: 00:22:19:04:ce:49 netfilter option must be specified for iftop-dump Could not open log file: No such file or directorySegmentation fault

so I create the log file folder "mkdir /var/bandwidth" and put command like this: sudo ./fitop-dump -F 192.168.0.1/32

now it's working, the log file bw-xxx have 4 column 。I think the 1 column is the time 2 column is the IP address ,but 3 and 4 column is 0. Although monitors IP in fact to have big traffic . so it cannot record the data which I want .

where has made the mistake ？