Re: Scanning 65K ports on 45 subnets

On Mon, May 23, 2005 at 08:00:38AM -0400, Chad McDonald
wrote:

> I have adjusted the following scan options:
> Port range to all 65K+
...
> When I
> attempt to scan even 1 subnet with each box, the scan time
> is ridiculous to the point of making the results useless
> (typically 2 or 3 days, if it completes at all.) Given
> that I have 45 class b subnets to scan, do any of you have
> any suggestions for remedying this problem?  

Which scanner(s) are you using and how are they configured?
Understand that UDP port scans are *slow* -- scanning all
possible UDP ports can take a day or more for a single
target! Also, this is just a drawback of UDP scanning, not
Nessus per se. Avoid it if at all possible.

Also, is there some type of a firewall either between
nessusd and the targets or on the targets? If it's dropping
packets rather than rejecting them, a scanner will have
until a timeout occurs for each port that's blocked.

George

--
theall@tenablesecurity.com
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