TCP/IP protocol question

[Naboman]

Hi

Im a little confused about what i need to know,so sorri if im a little bit unespecific.
I connect to a server via telnet. I think there are more comunication ways than telnet,i mean,first of all there is 1010010101 kind,in the middle there is the one im searching,and after,the one i recive and send by using telnet.

Does anyonne knows the protocol i mus use in order to be able to talk to another computer and being able to comunicate with it the way i have tryed to specific?

Thanks for any help

Antonio

 

[Stijn147]

Read this about the OSI Network Model:

http://www.ussg.iu.edu/usail/network/nfs/network_layers.html

(don't wory about Session and Presentation Layer, those aren't used)

Is your question about sending IP-packets or about opening TCP-connections ?

 

[Naboman]

I think its about sending ip packets,after reading that doc,id say i must edit packets, see how they come and the 'languajes' they use, and try to make and answer packets in another different format than telnet...

Any idea?

Thank you for help

 

[manarth]

TCP/IP is a protocol to allow 2 computers to communicate.

Telnet is a protocol which uses TCP/IP to act as a terminal emulator for a remote systems (using TCP port 23 normally). FTP is a protocol which uses TCP/IP to transfer files (port 21). HTTP is a protocol which uses TCP/IP to transfer webpages (port 80).

Hope this clarifies the protocol layers.

The telnet protocol allows varying terminal communication to be used (for different remote server systems); e.g. VT100; DEC; ansi.

Perhaps if you post what you're trying to achieve, we may be able to help more.

<marc> i wonder what will happen if i press this...[ul][li]please give feedback on what works / what doesn't[/li][li]need some help? how to get a better answer: faq581-3339[/li][/ul]

 

[Naboman]

I own a mud,an online text based game which runs under a linux server.

It can be played with any telnet terminal.

The problem is,and i have been asking and it seems there is no other one in world who got it,that one of the players of my mud got a way to send orders to the mud like if he was a implementor,being able to change his account and so.

With the way the mud runs,using telnet this is impossible,because the server asks for the level of the character in order to let him use implementors orders or not.

I cant ban him from the mud because he has a dinamic IP.
I would like to get how he does it to try to prevent him and any other from doing so... i tryed to ask him how he did so and he told me several things...one of them,that he had to use linux to being able to do so... and other which made me think what i started asking on this post,that stuff about comunication ways...

Thank you for help

 

[jrbarnett]

Hi,

If your mud game runs under a telnet session, surely your user must login to the server before starting it up. Just block his login (stick a * in front of the password field in /etc/passwd to disable it against his username).

You may want to grab a copy of the introduction to tcp/ip from my website

http://www.jrbarnett.freeserve.co.uk

as an intro to the protocol.

I suggest also running a port scanner against your server to see what is open and running in case he has managed to get some back door installed on it.

Regards,

John


John Barnett
--
Please consider awarding me a star if you feel my posting has been useful. Thank you.

 

[Naboman]

Is there no way to work with something similar the concepts i try to explain on my first post? i mean,that is the way he told me...

I pay for the server,and i eventually change it,and he is able to do it with any server i use,so dont think its any troyan...

Any way,banning him will just make he changes his nick and play untill i get that nick is he,and ban hem again... id like to be able to do what he does in order to try to change some from my mud code...

Im sorry i wont be able to answer for 1 week or so,but ill be on the forum everytime i can.
Thank you.

 

[manarth]

naboman - you're post indicates a big possibility of a trojan: a trojan is a program which allows the other person to access your system as though s/he were sitting at your PC. They can even watch what you type, so they could know your passwords.

It's (probably) either a trojan or a security hole in the code of the MUD.

You could try a packet sniffer (e.g. ethereal) to capture traffic, but you'd need a thorough understanding of TCP/IP to translate the data into what the hacker is actually doing.

You can't really mess with TCP/IP protocol; you may be able to replace telnet with a different protocol - be aware this would probably be a major programming undertaking (I use the caveat &quot;probably&quot; because I don't know how your MUD was created / programmed, but even so, it would need considerable knowledge of networking protocols to start fiddling with this).

<marc> i wonder what will happen if i press this...[ul][li]please give feedback on what works / what doesn't[/li][li]need some help? how to get a better answer: faq581-3339[/li][/ul]

 

[Naboman]

Ok,i have searched for trojans on the sistem,i downloaded some famous trojan cleaners,and they told me there is no trojan... x(

I got an idea... probably unusefull... but... is there any way to dialoge with a telnet server than via telnet?
Which other protocols than telnet could alow me to chat with the server too? Id like to get an answer to that please. ftp already tryed and that didnt help.

Any idea?

Thanks for help

 

[jrbarnett]

Naboman
Have you run a port scanner against your server to see which ports are open?

John