UGN Security Forums UGN Security: Underground General Ports

Would someone kindly explain how ports work

I would run out of numbers before I ran out of ways to interpret the meaning of ports in the Anarchy forum...

my bad, i posted in the wrong [censored] forum.

A port is basically the entrance to your computer from the outside world. Think of it as a door. A socket from a program opens up a port, (an example is apache opens up port 80 because that's the http port), and then other programs can connect to the computer trough port 80 once it's opened and something is listning. So the basic definition is a door into your computer. A port scanner will tell you what doors are open on the computer you are scanning.

LOL PORT SCANNERS ARE FOR N00BS MDOS is for advanced

Well Mac-10Daddy, while you telnet to each of the 65000+ TCP ports in DOS, we'll keep using port scanners...

/me kicks Mac-10Daddy on the balls
you are an idiot. and don't even try to give me a smart-[censored] answer i can already tell you know [censored]. unless you were trying to be sarcastic which i know you weren't

Wtf is MDOS? is it like DDOS? or maybe the retard is thinking of MSDOS... anyways enough flaming. Think of ports as gateways, doorways, openings, or um ports on your computer that allow people to access the information on it, whether its in the form of a webserver, telnet server, mail server, or other things of the sort. Ports on your computer only to be opened if your acting as a server and for direct connections. Firewalls work by not allowing TCP conections to these ports, although they are still open...
The best way to close open ports is to shut down the service thats keeping them open such as NetBEUI that keeps 137 138 139 open I believe. How people acn do NBTstat look ups on you and all that. If you wanna learn more read about TCP/IP as you can cause that what the nets based on. Theirs shitloads that I could go into about ports but I dont wanna take the time. (If Im wrong about anything feel free to correct me).

65535

Yes Gizzy...and "65000+" covers that.

Gizzy is just trying to show off that he knows exactly the number of ports

lol
how old is this topic?
anyway. heh. MDOS is l33t! heh
does this mean that guy cant tell the difference between an OS and a port scanner, sad...
anyway, a port is where ships go.
think of your comp as a body of water, people are boats, and ports are places in which they can dock or enter it. Sometimes u need harbor passes like user names or passwords or bohemian slave girls. Sometimes the harbor cant be entered because its blocked off for the day(firewall). And maybe its just there because a program has to open a port to make a connection with another port. i.e. internet explorer to a website, and theres nothing u can do after u access the port. Basically like the port is there so 2 merchants can trade privately back and forth <img border="0" alt="[Thumb]" title="" src="graemlins/thumb.gif" />

ph33r my analogy.

lmfao

MsDos = lame not port scanners

Where the [censored] do you come off saying Port Scanners are lame? It is one of the fastest if not the fastest way to see if there is any ports open.

MsDos at least the commands I know would be about the SLOWEST and least effective method of scanning for ports on a range let alone a single IP address..

Hm...just to note a few things that haven't been made clear enough:

1. There are two types of ports: TCP and UDP. TCP create three-way-handshake connections, UDP just receives packets.
2. I thought there were 32676 ports, not 65000+? Possibly I am wrong - 32676 is the limit on an int, but a unsigned int (this is for C datatypes) would run up to 65000+.
3. You should close all the ports you can on your computer.
4. You don't just "open" ports. You have to assign a program (known to the unix world as a daemon!) to listen to the port.

Now for some Mac-10Daddy bashing:
You are a worthless [censored]. Why the [censored] do you contaminate these boards with your worthless comments. I can't believe I just gave up 1x10^-8375 cents worth of bandwidth and time to download and read the HTML that comprised your message. It's your kind that disgusts me. Get the [censored] off this board you worthless turd. Go find an ugly girl to finger, or better yet, your dog.

What a worthless [censored].

Scallion Corrections:

An int may consist of 2 bytes in 16-bit operating systems. But the int has 4 bytes on 32-bit systems. Output sizeof(int) on your machine to verify my words.

Yes, there are most DEFINATELY 65536 ports. 0-65535. Port 0 is reserved for a randomly selected available port by the system. In the TCP/IP protocol there is 2 bytes reserved for the port specs. So naturally they'll use it to its full potential.

I think my comment related two things of interest to me:

1. I am unsure of how many ports are on a system (Although this has changed; you have now informed me!)
2. Did the developers of whatever system you're using use an int or an unsigned int or a different datatype.

I never claimed there's only 32676 ports I expressed my lack of knowledge concerning the total number of ports on a system and provided a possible number that might be there, lol.

jebus christ, Scallion you dont have to be so elite hehehe. SR: I think you have competition

this was just to comment on how l33t Scallion's post was

"2. Did the developers of whatever system you're using use an int or an unsigned int or a different datatype."

signed or unsigned is irrelevent to my point. You said:

"32676 is the limit on an int, but a unsigned int (this is for C datatypes) would run up to 65000+"

This would be true on a 16 bit system. For a 32-bit system I'd rewrite it like this:

"2147483648 is the limit on an int, but a unsigned int (this is for C datatypes) would run up to 4294967295"

A lot of long-time programmers think that int is only 2 bytes. Lots of people make that mistake. But now in the days of 32-bit systems, it's 4. Just letting you know. I'm 100% sure on this.

Here, I'll diagram it again like this for ya - just trying to express myself in a way that is easily understood:

unsigned int on a 16-bit system
0 to 65535

signed int on a 16-bit system
-32768 to 32767

unsigned int on a 32-bit system
0 to 4294967295

signed int on a 32-bit system
-2147483648 to 2147483647

---

Now, for proof, write a small C program. Output the return value of 'sizeof(int)' and you'll get 4 on 32-bit systems, and 2 on 16-bit systems.

SR, dude, you're freakin' out!

As to whether something is signed or unsigned has to do a lot with the maximum value that can be assigned to that variable.

The first bit of a signed int is a 1 or a 0 (duh, bit!) that determines what the sign of the value is. This takes 1 bit away from the overall size of the int - hence, if we count up our powers of two, then we'll realize that for every bit that is lost, the total value a int can hold is decreased by a power of 2.

I totally understand your 16-bit and 32-bit explanations (NEWS FLASH: contrary to public belief, no, i am not a total idiot! lol) and I'll even bet I could find out what it would be for a 64-bit system too!

And...um, I know C too, I can write a quick program. Thanks. Yep. C++ too, i'm leet out the wazoo. NONO, i'm not "elite", only lamers can be "elite".

heh, nah, I'm not freakin out. When my point isn't coming across properly, I get very verbose. I was just trying to tell you about var sizes, and you think I'm talking about max values. Two subtly different things. The conflict probably arose cause you look at var types in terms of value, and I look at them in terms of size. When considering a var's size, sign is irrelevent - that's my point.

I just felt compelled to tell ya that int is actually 32-bit and why cause you said it was 16-bit so-to-speak.

(you don't have to prove that you're not an idiot by proving you know how negative numbers is translated from binary. )

hmm, good point, i forgot to mention programs must be listening on ports. guess it was just implied.

Ok. Max values vs. var sizes understood.

Hurrah...someone valued my comment that you have to put a listener on ports...

yeah, ur j33t