iftop -- unable to get IP address for interface

Ramonvel · 05-27-2008, 10:20 AM

Hi Guys,

I installed iftop to monitor bandwidth on my eth0 and maybe eth1 if necessary. But when I run iftop, this is what I get :

interface: nr0
Unable to get IP address for interface: nr0
ioctl(SIOCGIFADDR): Cannot assign requested address
MAC address is: 00:00:00:00:00:00
pcap_open_live(nr0): bind: Network is down

The only interface that has an ip add is eth0, which I'm currently working on through SSH. I need help please.

Thanks in advance,

MensaWater · 05-27-2008, 10:43 AM

It appears to think that you have an interface named "nr0".

Not sure what the heck nr0 is though. On doing a Google search I find old 1996 references to a device of that name for a software called "netrom". In turn I find "netrom" is a utility for Amateur Radio stuff. Do you have that installed?

According to man page iftop goes to the first interface it thinks you have configured. You can however specify the correct interface with the -i flag: e.g. iftop -i eth0
It shouldn't try nr0 if you do that.

Ramonvel · 05-27-2008, 12:45 PM

Hi jlightner,

Yes it works with the -i flag. I'm not really sure if I have anything that refers to Amateur Radio. I'd like to know if it's possible to do any modification on an iftop script to refer to eth0,eth1, etc.

However, your post, completely resolved my problem.

Thank you for your help,

MensaWater · 05-28-2008, 07:47 AM

What distribution and version of Linux are you running?

Is this a newly installed system?