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 :p

[grid]

You're very welcome!

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