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#1 2014-10-20 03:23 PM

bsnayak
Member
Registered: 2014-10-20
Posts: 3

client server program which connects clients with specific IP & Port

hello,

Instead of using default client server connection , i want to design specific client based server program, which will first check a specific client 1 with IP1 and port 1 and client 2 with IP2 and port 2 are connected. If both are connected then exchange of information between two clients can be possible..

Kindly suggest, How can i code it..?? possibly share some references which would be helpful..

Thank you

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#2 2014-10-20 07:53 PM

RobSeace
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From: Boston, MA
Registered: 2002-06-12
Posts: 3,847
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Re: client server program which connects clients with specific IP & Port

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#3 2014-10-21 10:56 AM

bsnayak
Member
Registered: 2014-10-20
Posts: 3

Re: client server program which connects clients with specific IP & Port

I will try to simplify like this..

I have my laptop which i want to run as server. I have two other systems with (IP1, port1, IP2, system2) , which are all connected through UDP connections with eachother. system 1 sends data to server, server modifies the data and sends to system 2.

similarly system 2 sends data to server and server sends the data without modifying to system 1. These datas are hexadecimal coded messages.

But all the codes i checked for multiple clients, they check like this,  which is connected first is treated as client1 and the one is second is client 2. How can i specify that client1 must be system1 with specification (IP1, Port1) and client 2 is system 2 with specification (Ip2, port2).

if both are connected the data exchange can take place..

Thank you

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#4 2014-10-21 11:08 AM

bsnayak
Member
Registered: 2014-10-20
Posts: 3

Re: client server program which connects clients with specific IP & Port

Instead of using default connection type like this

s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)

how can i create a socket for specific ip and port.
if my ip is 127.0.0.7 port 1901
how can i create a new socket with this values, what functions needs to be changed ??

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#5 2014-10-21 12:24 PM

RobSeace
Administrator
From: Boston, MA
Registered: 2002-06-12
Posts: 3,847
Website

Re: client server program which connects clients with specific IP & Port

Well, if you're using UDP, there really are no "connections" at all...  It's a connectionless protocol...  So, I assume by who connected first, you just mean the first one to send any message to the server?

If you want the clients to use a specific IP and/or port#, then use bind()...  (You can only bind to a valid local IP that corresponds to one of your network interfaces, but you should be free to pick any port# that's not in use...)  But, beware: if the clients are behind a NAT box, then it may very well change the values that the server ultimately sees the messages coming from!  So, relying on a specific port# to identify the clients isn't really the most reliable approach...

What it sounds like you really want is some form of login/authentication...  Have each client provide its ID in the form of a login name and password/key/whatever on their first message to the server...  Then, the server will be able to distiguish between them by that name and treat them appropriately...

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