Nmap extremely slow on my laptop

[Hyne]

Hi all, I've got this big problem using nmap in my laptop, it runs extremely slow, a normal scan takes normaly more than 10/15 minutes, I'm experiencing this issue since the first time I installed nmap on Windows.
I recently installed Kali, but this problem persist, I think that is because of the Wi-Fi card because if I try to run the same nmap scan inside a virtual machine it executes perfectly in less than 10 seconds.
Here are my specs:

Laptop: Acer Aspire E5-571G-71E7
OS: Kali GNU/Linux Rolling 64-bit
RAM: 8 GB DDR3
CPU: Intel Core i7-4510U 2.0GHz
Wi-Fi Card: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter

Output running lspci -v:

02:00.0 Network controller: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter (rev 01)
	Subsystem: Foxconn International, Inc. QCA9565 / AR9565 Wireless Network Adapter
	Flags: bus master, fast devsel, latency 0, IRQ 19
	Memory at b3400000 (64-bit, non-prefetchable) [size=512K]
	Expansion ROM at b3480000 [disabled] [size=64K]
	Capabilities: [40] Power Management version 2
	Capabilities: [50] MSI: Enable- Count=1/4 Maskable+ 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Virtual Channel
	Capabilities: [160] Device Serial Number 00-00-00-00-00-00-00-00
	Kernel driver in use: ath9k
	Kernel modules: ath9k

Output running iwconfig:

eth0      no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:"TeleTu_DC0B1A0C599E"  
          Mode:Managed  Frequency:2.462 GHz  Access Point: DC:0B:1A:0C:59:9E   
          Bit Rate=1 Mb/s   Tx-Power=15 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=48/70  Signal level=-62 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:16   Missed beacon:0

lo        no wireless extensions.

Output running route -n:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    600    0        0 wlan0
192.168.1.0     0.0.0.0         255.255.255.0   U     600    0        0 wlan0

[grid]

What's the nmap command you are running? Depending on the scan, it may take awhile.

Try changing the timing option (-T). I think the default is 3, but try upping it to 4 and see what happens.

It looks like the transmit power on your wireless card is pretty low. If your wireless card supports it, upping the transmit power may help also.

[Hyne]

Hi grid, thanks for the response, I'm running the following command:

nmap scanme.nmap.org

If I try with -T4/-T5 flags it still takes at least 10 minutes to complete.

For increasing the power do you mean running:

iwconfig wlan0 txpower 30

Or by using another command?

Thanks again.

[grid]

No problem

Hmm, since that's an external box, you might be having lag over the net, or DNS issues. Try using IP instead of DNS name, and see if that helps your speed. You could also try using nmap's dns parameter, set it to 8.8.8.8 (Google's public DNS server).

Yeah, that's the command on iwconfig.

[Hyne]

Hey grid thanks again for the suggestions, I came to the conclusion that these scans takes forever because of the router firewall, I tried to disable it and my scans now takes least than 10 seconds.
Do you know how can I keep my firewall enabled and running nmap normally?

On the router panel I've got the following options below "Firewall":

• Access Control
• MAC Filter
• URL Blocking
• Schedule Rule
• Intrusion Detection
• DMZ (Demilitarized Zone)

Do you want that I post the available settings inside each option?

Sorry for my English

[grid]

You're very welcome!

Unfortunately, firewall configuration is a little out of my league.