nmap question

[Vurraz]

Hello,

I've got one simple question - Is Nmap using up less bandwith from my connection if I set Nmap to work on -T1 speed?

Thanks in advance!

[Vurraz]

Oh, and another question came to mind - Am I going to be less stealthy if I use multiple T1 scans at the same moment? (Like a -T1 sS scan in one terminal, and a -T1 -sU scan on another terminal within the same computer)

[winter_soldier]

Depends on what your scanning.

• T1 is a far less aggressive scan when compared to T5, you might want to look into other speed options
• sS can be mistaken for syn-flood attacks on some basic firewalls and IDS systems, sometimes sT is quicker across network boundaries
• sU UDP can be very unreliable, combine it with Application triggers -A (aggressive scan) to more accurately determine open ports, but then increases the chances of detection
• Also nmap inserts a fixed string into all packets any IDS (example Snort) can easily fingerprint an nmap scan, think of alternative scanning engines

When in doubt or unsure

man nmap