View Full Version : NMAP scanning massively slow in Kali
There is something wrong with my Kali VM and I cannot figure it out. Would you be able to offer some troubleshooting suggestions?
Simply put, it cannot conduct nmap scans with any degree of speed. It used to be fine, but since upgrading to Kali 2 it seems to have gone downhill.
For instance in my host machine I can nmap www.megacorpone.com and receive results in about 7 seconds. The same scan inside the VM is taking about 300+ seconds. Not acceptable!
What could be hindering the scan? The machine has plenty of RAM, and I the internet connection on the host machine seems fine.
Any ideas for troubleshooting this?
I'd try putting nmap in extra verbose mode (i.e. with the -vv parameter) and/or debug mode (i.e. with the -dd parameter) and see what it tells you. You could also try changing the timing parameter (-T) to 4 or 5. I think 3 is the default when you don't specify anything.
Are you using one of the pre-made VM images from offensive-security.com?
I'd try putting nmap in extra verbose mode (i.e. with the -vv parameter) and/or debug mode (i.e. with the -dd parameter) and see what it tells you. You could also try changing the timing parameter (-T) to 4 or 5. I think 3 is the default when you don't specify anything.
Are you using one of the pre-made VM images from offensive-security.com?
VM image. Now one thing I *should* mention is that I had trouble upgrading. I got the dreamed "Uh oh" something went wrong message. Now, I still get this whenever I reboot but if I say ctrl-alt-F1 and say startx in a second console I get the GUI back, but upon subsequent reboots I have to keep doing this.
Could it be that this second console doesn't have the processing power it should have? It might be totally unrelated.
Oh, you went from Kali 1.x to Kali 2. For what it's worth, I had trouble with the upgrade (due to some self-inflicted issues :o ) so I ended up installing Kali 2 fresh. Haven't had any problems since.
Hmm, maybe...but it's not something I've run into (and I've been using Kali since the BackTrack 2 days). You could try running top and see what it reports.
Oh, you went from Kali 1.x to Kali 2. For what it's worth, I had trouble with the upgrade (due to some self-inflicted issues :o ) so I ended up installing Kali 2 fresh. Haven't had any problems since.
Hmm, maybe...but it's not something I've run into (and I've been using Kali since the BackTrack 2 days). You could try running top and see what it reports.
I tried a fresh Kali VM. I still get a major difference:
MacBook: 0.5s
Kali VM: 2.0s-4.0s
This is in NAT mode. That a normal level of lag for address translation? It still seems quite excessive.
No, that kind of lag in NAT mode seems really high. Have you tried nmap in extra verbose (-vv) or debug (-d or -dd) mode?
No, that kind of lag in NAT mode seems really high. Have you tried nmap in extra verbose (-vv) or debug (-d or -dd) mode?
*sigh* I just gave up and started anew with a standard image. Works like a charm now. Something was badly screwed up in the upgrade.