Firewall Scans are Inconsistant

Posted on 2004-04-10
Last Modified: 2013-11-16
I have a computer thats a little over two years old.
I am running Win XP Home Ed with AOL/DSL utlizing
McAfee “Personal Firewall Express” provided through
AOL.  I get inconsistant results are GRC's Firewall Scan.
The first couple of time during the day that I go to it,
it shows passed with all common ports "stealthed."
Later say three or four hours or even later in the evening, it will show: one or both of the following:

Port 25       SMPT        OPEN

Port 1025   HOST         OPEN

When I go to "Task Mgr" the identical applications and
processes are running.  I am quite sure that I do not have any virues, trojans or adware on the machine.

Since we are using AOL mail, can't figure out why the
SMPT port would be open at all?

Question by:LRI41
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LVL 35

Expert Comment

ID: 10798461
Have you sent or got email before you have seen this? If you make a port scan from outside, the scanner recognizes, on which ports is responding a service. The ports are closed after a while, not quite after releasing the connection. I#m not sure, how AOL is working, but it may be, that they uses these ports for communication with the client software.

Secondary, if you scan your machine from outside, it must not be your machine, which is responding. As you are routed through the AOL software, it maybe that AOL responses for your actual IP address. If the port is really open is hard to determine, as the AOL Software is between your machine and AOL.

What you can do is, use a secondary machine and telnet your current IP on port 25, if your scanner tells you, that the port is open. The banner text, which coes back, may a hint, who is responding on port 25, your machine or AOL.
LVL 10

Author Comment

ID: 10802673
After determining my current IP for the current use time , could I
engage the services of my son who lives near by (   say an hour away) and give him the Ip address and have him telent my current IP on such and such a port?  If so, I think we may also need some
direction or how one does that?

I did find the following via google:

Im new to the telnet. I know I go to Start>Run> and type in telnet. Then i press o to connect and type in my ISP's email and use port _____

This is a Mac forum, but I have a suggestion.
Start > Run..
then type "telnet IPaddress 25" where IPaddress is the IP address of your ISP's mailserver.
Then when the window opens, hit 'c' or whatever special character your client requires.

Telnet for windows connect command is
open IP port
open x.x.x.x 25

Unless you have an older version, if you do, start> run> telnet>
then from there click connect and work from that!!!
LVL 35

Accepted Solution

Bembi earned 200 total points
ID: 10804908
> After determining...
Yes, as long as your session is still open, you may get a new IP Adress after a new logon

> I did find the following ...
Do the following:
- Open DOS promt (on the second machine) : Start - Run - type cmd - OK
- You will get the black DOS promt screen
- Now type in "telnet 25", where 111.... is your current IP address and 25 is the port, reported as open.

You will get back now a banner line, like
220 servername Microsoft ESMTP MAIL Service, Version: 5.0.2195.6713 ready at  Mon, 12 Apr 2004 14:41:39 +0200

or something similar. Usually this is resultcode, server name, service name, time, timezone
but as every server has its own banner, it may different. Important information is the server name. If this name points to something of AOL, you can be sure, that your port scanner gets a response directly from AOL, not from your machine. If you get back a blinking cursor and no banner, wait until the command is timed out (after a few seconds), you will get a error message,. If the error message comes promt, the port is closed, if you have to wait for a few seconds (10-30) until the error message comes, it seams to be, that there is a service, but not responding. In that case, I would like to know the exactly error message.
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Author Comment

ID: 10823565
Bembi, thanks for your reponse, due to some unexpected events that came up and my son's work
schedule, probably will not get a chance to work on this till this week end, my guess is may be this coming Sunday, so bear with us.  No Need to Reply.
LVL 10

Author Comment

ID: 10854667
Bembi, Just to keep you up to date, I scanned
5 or 6 times this morning and wouldn't you just
know each and every time, complete "stealth"
on all ports.  I even sent a  test email to myself which was received, still nothing.  So as soon as I find either
25 or 1025 open and my son is available, we will do the test and I let you know what is responds.  My guess is that your analysis and or guess is correct and
its AOL's response and not my computer.  Just to keep you advised and I haven't forgotten and as soon as we can do the test and get the results , I will post it here.
Se no need to reply until then nor will I post until then.
LVL 10

Author Comment

ID: 10863754
Bembi:  Well today the scan showed Port  25 SMPT
open and I got a hold of my son and he did the telnet
and the message returned as follows:

"Connecting To (IP Number only not port number). . . .    .Could not open connection to the host, on port 25:  connect failed"

We were also on the phone at the same time, and
as he was emailing it to me, I went back to Gibson's site and did another scan right then which still showed
port 25 SMPT open!!!

LVL 35

Expert Comment

ID: 10864621
Means, nothing comes back, that is fine.

Two additional tests, to be sure, your machine is safe:
Open DOS promt and type
netstat -n

you can see there all open ports on your machine. That does not mean, that all these ports are open to the public world, that means only, that there are a few ports, which are used internal. If you can not find port 25 there, but Shields Up reports port 25 as open, you can be sure, that your port 25 is closed, as no service is listening on it.

Another tool to test is can you find here:;de;310099

Also, if you find port 25 open, use the complete port scan to test all of the first 1024 ports and see, if the results are the same.

I assume, that this is a routing issue of AOL. Also compare the IP Address Shields Up is showing with the IP Address you can find, if you type IPConfig /All at DOS promt.
LVL 10

Author Comment

ID: 10865244
Bembi thanks for all your time, information and advice.
I tried to run the additional tests but the scan tonight like
Yesterday came back "Stealthed"  I have taken enought of your time and in the future when the stars are right, and the ports show they are open , I will run the other tests and if I have
additional questions I will post a new questions.  I did find the
English version:

Another tool to test is can you find here:;de;310099

Use English:;en-us;310099

But haven't download it yet, I will see what the other ones show first.  Again Thanks!!!!
LVL 35

Expert Comment

ID: 10867158
Upps, havn't realized, that its the german version.

Take care.

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