Re: -Pn, should I use it or not?

[Jacek Wielemborek <d33tah () gmail com>]

W dniu 27.03.2015 o 00:29, Hongyi Zhao pisze:
> Hi all,
>
> When I do a port scanning with the following parameters:
>
>
> nmap -T4 -n -p60088 --max-retries 1 --script "+socks-open-proxy and not 
> http-*" 50.57.77.252
>
> Should I also add the -Pn switch to it or not?  I mean, taking the   
> results' correctness and efficiency into account, should I add it or not. 
>
> Any hints?
>
> Regards

(note that it's late here and I'm a bit sleepy)

If you know that the host is up, it's pointless. Without -Pn, Nmap by
default does "-PE -PS443 -PA80 -PP" and an ARP ping if possible. This
means a SYN to port 80, an ACK to 443, ICMP echo and address mask query.
If all of them fail, you'd get a false negative. The script wouldn't run
without a port open anyway, so I don't think there's any gain to not
using -Pn in your case.

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