Checking ports on a laptop

[Tosca]

Hi Everyone

I have a single laptop behind a Netgear router connected to an ADSL line. I
access e-mail and surf the net but do little else. I have ZoneAlarm on the
laptop, in addition to the Firewall in the router. I have XP Pro and have
turned off it's firewall.

I ran two online port scans and one said that some ports were "Blocked"
(good, according to the site) whilst others were "Closed" (less good,
according to the site). The other online port scan said that the same ports
were "Stealth" (good, apparantly). One site was http://www.sygatetech.com
whilst the other was http://www.grc.com. I'm not sure why these reputable
sites gave different results. What's the difference between "Blocked",
"Closed" and "Stealth"? Which is best, given my limited activity (I also
use ftp occasionally to access other sites but don't want anyone to probe my
laptop to access any data) and how do I alter the status of the ports?

Maybe these questions demand too detailed a response here and, in that case,
can anyone point me to a "fools guide" that I could use as a springboard to
delve further? I've googled but the information that I obtained seemed to
confuse me more.

Thanks for your time and patience.

 

[Phil]

Blocked and stealth are basicly the same thing. It means not even a port
scan reveals that a port even exist. It's hidden and no connections are
allowed.
Closed means that the port can be seen, but a connection cannot be
established until something triggers it to open.
You want stealth/blocked all the time. Find out what ports were marked as
just closed, then google for a program clled TCPView and see what program is
using that port, then config the program or shut it down.

 

[Guest]

I almost agree. In the case of 'Closed' ports, if the port is something like
port 80 or port 21, then you'd better not lock the port or you won't do a lot
of surfing (or anything else online).

Hovel, I wouldn't worry too much. You have ZoneAlarm behind a hardware
firewall and very little dangerous activity is going to get past tht combo.
One thing I would suggest, though, is to go into the router config pages and
change the base DHCP address and default admin password. That way the bad
guys are going to have a very hard time hacking into therouter setup to get
past it.