nmap isn't working.

[HodLuM]

Hey guys, I know nmap comes pre-installed in BackBox but I can't do any scans.


when I do nmap x.x.x.x, it gives me this error:

Starting Nmap 6.00 ( http://nmap.org ) at 2013-07-29 20:28 PKT
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers


I also tried doing it with sudo, and adding the -PO parameter, but that doesn't solve the problem.


How can I solve this problem?

[weVeg]

Try this http://tinyurl.com/m9bj56x

[b4d_bl0ck]

Hi HodLuM ,
yes, follow the link posted by weVeg. (LOL weVeg, we are specialized in answering at the same time! :P)

If you cannot solve, try posting the content of your /etc/resolv.conf
Also check if your DNS server is working properly... are you able to resolve hostnames and reverse resolve IP addresses? For example you can check with:

Code Select Expand

host google.com
host 8.8.8.8

Bye, let us know. ;)

[weVeg]

@bad_block: YO bro!! ;)
@Hodlum: follow bad_block's suggestions!! =)

Bye bye!

[HodLuM]

sup b4d_bl0ck and my man, weVeg.


as b4d_bl0ck told me to enter those commands, I did. and here are the outputs:

hlum@b0x~$ host google.com
google.com has address 173.194.35.97
google.com has address 173.194.35.105
google.com has address 173.194.35.103
google.com has address 173.194.35.96
google.com has address 173.194.35.101
google.com has address 173.194.35.110
google.com has address 173.194.35.104
google.com has address 173.194.35.102
google.com has address 173.194.35.100
google.com has address 173.194.35.99
google.com has address 173.194.35.98
google.com has IPv6 address 2a00:1450:4006:802::1003
google.com mail is handled by 30 alt2.aspmx.l.google.com.
google.com mail is handled by 50 alt4.aspmx.l.google.com.
google.com mail is handled by 10 aspmx.l.google.com.
google.com mail is handled by 20 alt1.aspmx.l.google.com.
google.com mail is handled by 40 alt3.aspmx.l.google.com.
hlum@b0x:~$ host 8.8.8.8
8.8.8.8.in-addr.arpa domain name pointer google-public-dns-a.google.com.


and /etc/resolv.conf does not exist. :S
I mean, that there is no resolv.conf in /etc/.

[weVeg]

and /etc/resolv.conf does not exist. :S
I mean, that there is no resolv.conf in /etc/.

This is your prob,

Code Select Expand


sudo echo "nameserver 208.67.222.222" >> /etc/resolv.conf
sudo echo "nameserver 208.67.220.220" >> /etc/resolv.conf


[b4d_bl0ck]

Yeah, let's see what happens ;)

[HodLuM]

thank you so much, weVeg. that solved the problem. I am no longer getting that mass_dns error.


this time, weVeg was faster against b4d_bl0ck. ;)

[b4d_bl0ck]

Yup HodLuM , I'm getting old :P
Anyways if you don't need to know the hostname, best practice is to instruct nmap not to do DNS reverse resolution with -n switch. This is more stealth and sometimes time-saving too.

Have fun! ;)

[weVeg]

Hodlum Tag solved, and enjoy nmap!
see you guys!! =)