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Telnet problem behind ADSL router plz help

Discussion in 'Ethical hacking' started by rahul_mawana, Feb 1, 2010.

  1. rahul_mawana

    rahul_mawana New Member

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    Hello frnds, this is my probs
    i want to connect my computer to my friend's computer using Telnet on internet, both systen has winxp sp2.
    he has airtel brodband connection,
    i have started telnet service on his computer and if i locally connect telnet on his computer as telnet 127.0.0.1 then it connects succsfully nd work perfectly.
    But if i connect his computer(server) to my computer(client) by his public ip(ip assigned by his isp)
    then it takes me on his router (BCM96338 ADSL ROUTER,His system is behind his isp router)
    and ask for user name and password.
    I know i will have to do some settings on his router but don't know what is that.
    One more thing both side has dynamic ip.
    Plz tell me frnds how can i do it
    Thank u
     
  2. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    look into DynDns, at www.dyndns.org, get a account, its free. To enable the telnet to work you will need to do port forwarding, set his router to forward port 23 to his internal IP. DynDns is dynamic domain naming service, you link a domain name with an IP address that gets automatically updated if you have dynamic IP's. So install dynDns on his computer just to update the IP of the domain name.
     
  3. rahul_mawana

    rahul_mawana New Member

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    Thank u SpOonWiZaRd,
    i try to do this and report u soon,
    one more thing SpOonWiZaRd,
    is there any other method of this,
    and can i make any tool that do this thing for me silently,
    Thanku
     
  4. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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  5. rahul_mawana

    rahul_mawana New Member

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    you said that i will have to port forward to his internal ip, but internal ip is also changed every time, m i ri8. so i will have to do setting every time on his router. plz clear my doubt. i m not expert. plz make me understand clearly. thank u
     
  6. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    Well if his got DHCP enabled and is using it then the only way to give him a fixed IP is by setting the router to give a IP according to the MAC address if the router has that option. Else his computer will need to have a fixed IP. Or do a port forward to all the computers from the router.
     
  7. rahul_mawana

    rahul_mawana New Member

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    No DHCP is not enabled. I think that computer is behind a router that is more secure other than that is nt behind the router. I know i can't do this until his computer doesn't have a fixed internal ip. But Spoonwizard a question is being arised in my mind that if i can't do this then how hackers do this. I think they also can hack a system that is behind a router as they put the trojan or RAT tool on victim computer and can acces system remotly so how do they make connection between trojan and own computer. If any body know how can it be done then plz tell me. By they way very very thank u spoonwizard for discusing 2 me on my problem and suggest me some way to do this if u got any other way to do this then plz tell me about tht. I also keep srching on Net until i dnt get any solution. Have a fabulas day Thanks again
     
  8. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    Can you get inside the router? Once you are in the router then just configure it to suit your needs.
     
  9. rahul_mawana

    rahul_mawana New Member

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    yes i can, i know user name and password for router. but i don't know how to confgre the router with which i can acces his system using his public ip.
     
  10. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    Turn off the router's firewall and try then.
     
  11. rahul_mawana

    rahul_mawana New Member

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    Nothing wo'nt happen,
    beco'z firewall is not blocking the connection.
    The matter is this that router has a runing telnet service on port 23,
    and if i make connection using public ip on port 23 then i am connected to router telnet service,instead of that computer whose ip i m trying to connect.
    So i think there is not any roll of firewall.
     
  12. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    Does the computer you are trying to access have remote desktop activated? If it does then set the router to forward port 3389 to the internal IP of the computer. make a normal RDP (Remote Desktop Protocol) connection to the external IP of the router, the router will then see that a connection to that port has been made and then it will pass the connection on to the internal IP you have specified on the router.
     
  13. rahul_mawana

    rahul_mawana New Member

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    but internal IP is changed every time when internet connection is established. so i think i will have to do setting every time on his router.
     
  14. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    If the internal IP changes then it means he has DHCP (Dynamic Host Configuration Protocol) enabled on the router and thus the IP of his machine will change everytime the computer connects to the router. ADSL uses dynamic IP aswell for the external IP, to overcome this problem of keeping track with the router's external IP you must configure DDNS (Dynamic Domain Naming Service) on the router. DDNS is when you link the router's IP address to a domain name that you create for free at http://www.dyndns.org e.g: the domain name that you create is router.office-on-the.net and then after you have configured the router's DDNS the domain name's IP address will be updated on a timely basis according to the external IP. To overcome the problem of the internal DHCP you will see that most routers have a ARP (Address Resolution Protocol) table on them that shows the IP address's of all the host's connected to them. All you do then is to configure the router to pass any traffic it recieves on port 3389 (That is RDP (Remote Desktop Protocol)) to the desired internal IP you want. Open RDP Connector on your computer, type in the DDNS domain name you registered and configured the router to use in the RDP Connection field, and click on connect. The router which you configured to use DDNS will see the RDP incoming connection on port 3389 and then it will pass the traffic to the internal IP you selected. Now you have a RDP connection to the internal IP on the other network. I think the firewall may block it on the other computer or the antivirus as it is an external connection. You can configure the router to forward many other ports this way like SMB (Server MEssage Block) port 445 to the internal IP or telnet on port 23, ftp on port 21 an so on.
     
  15. rahul_mawana

    rahul_mawana New Member

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    This is perfect solution spoonwizard, u r master,i try it and report u soon THANK U very much.
    One more thing i want to learn all networking terms, can u provide me some weblink for networking topics.
    Thanks again
     
  16. SpOonWiZaRd

    SpOonWiZaRd Know what you can do.

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    No problem, if you do it right it will work.
     

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