This is probably too simple a problem but I am not able to find any
answers to it.
I was having an instant conversation with somebody using yahoo
messenger but could not ping to that persons machine and neither could
he ping to mine, is this possible? And if it is please tell me how to
solve this problem?
Thanks a lot
Rohit

: This is probably too simple a problem but I am not able to find any
: answers to it.
: I was having an instant conversation with somebody using yahoo
: messenger but could not ping to that persons machine and neither could
: he ping to mine, is this possible? And if it is please tell me how to
: solve this problem?
: Thanks a lot
: Rohit
:
:
:
:

If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.

The firewall needs to be configured to accept echo requests.


To understand recursive, first you need to understand recursive

: : This is probably too simple a problem but I am not able to find any
: : answers to it.
: : I was having an instant conversation with somebody using yahoo
: : messenger but could not ping to that persons machine and neither could
: : he ping to mine, is this possible? And if it is please tell me how to
: : solve this problem?
: : Thanks a lot
: : Rohit
: :
: :
: :
: :
:
: If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
:
: The firewall needs to be configured to accept echo requests.
:
:
: To understand recursive, first you need to understand recursive
:
:
Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
Thanks a lot
Rohit

: : : This is probably too simple a problem but I am not able to find any
: : : answers to it.
: : : I was having an instant conversation with somebody using yahoo
: : : messenger but could not ping to that persons machine and neither could
: : : he ping to mine, is this possible? And if it is please tell me how to
: : : solve this problem?
: : : Thanks a lot
: : : Rohit
: : :
: : :
: : :
: : :
: :
: : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: :
: : The firewall needs to be configured to accept echo requests.
: :
: :
: : To understand recursive, first you need to understand recursive
: :
: :
: Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: Thanks a lot
: Rohit
:


Most likely a firewall.
To understand recursive, first you need to understand recursive

: : : : This is probably too simple a problem but I am not able to find any
: : : : answers to it.
: : : : I was having an instant conversation with somebody using yahoo
: : : : messenger but could not ping to that persons machine and neither could
: : : : he ping to mine, is this possible? And if it is please tell me how to
: : : : solve this problem?
: : : : Thanks a lot
: : : : Rohit
: : : :
: : : :
: : : :
: : : :
: : :
: : : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: : :
: : : The firewall needs to be configured to accept echo requests.
: : :
: : :
: : : To understand recursive, first you need to understand recursive
: : :
: : :
: : Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: : Thanks a lot
: : Rohit
: :
:
:
: Most likely a firewall.
: To understand recursive, first you need to understand recursive

: Actually I have made a simple program using winsock to send a message from one computer to another. The client sends a message and the server recieves it and displays it using a messagebox. My friends keep telling me that supplying the IP address is not enough as there are other issues such as subnets and gateways. But dosen't the socket interface take care of all this I ask this because there are no functions in sockets that take parameters such as subnet mask's and gateways etc. Any help would be gladly accepted
Thanks
Rohit
:

: : : : : This is probably too simple a problem but I am not able to find any
: : : : : answers to it.
: : : : : I was having an instant conversation with somebody using yahoo
: : : : : messenger but could not ping to that persons machine and neither could
: : : : : he ping to mine, is this possible? And if it is please tell me how to
: : : : : solve this problem?
: : : : : Thanks a lot
: : : : : Rohit
: : : : :
: : : : :
: : : : :
: : : : :
: : : :
: : : : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: : : :
: : : : The firewall needs to be configured to accept echo requests.
: : : :
: : : :
: : : : To understand recursive, first you need to understand recursive
: : : :
: : : :
: : : Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: : : Thanks a lot
: : : Rohit
: : :
: :
: :
: : Most likely a firewall.
: : To understand recursive, first you need to understand recursive
:
: : Actually I have made a simple program using winsock to send a message from one computer to another. The client sends a message and the server recieves it and displays it using a messagebox. My friends keep telling me that supplying the IP address is not enough as there are other issues such as subnets and gateways. But dosen't the socket interface take care of all this I ask this because there are no functions in sockets that take parameters such as subnet mask's and gateways etc. Any help would be gladly accepted
: Thanks
: Rohit
: :
:
:


Right, all you need to supply is an IP address and a port number.

If the receiving machine (the server) has a router/firewall, it needs to have the port open that you wish to use to listen for connection attempts from the client.


To understand recursive, first you need to understand recursive

: : : : : : This is probably too simple a problem but I am not able to find any
: : : : : : answers to it.
: : : : : : I was having an instant conversation with somebody using yahoo
: : : : : : messenger but could not ping to that persons machine and neither could
: : : : : : he ping to mine, is this possible? And if it is please tell me how to
: : : : : : solve this problem?
: : : : : : Thanks a lot
: : : : : : Rohit
: : : : : :
: : : : : :
: : : : : :
: : : : : :
: : : : :
: : : : : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: : : : :
: : : : : The firewall needs to be configured to accept echo requests.
: : : : :
: : : : :
: : : : : To understand recursive, first you need to understand recursive
: : : : :
: : : : :
: : : : Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: : : : Thanks a lot
: : : : Rohit
: : : :
: : :
: : :
: : : Most likely a firewall.
: : : To understand recursive, first you need to understand recursive
: :
: : : Actually I have made a simple program using winsock to send a message from one computer to another. The client sends a message and the server recieves it and displays it using a messagebox. My friends keep telling me that supplying the IP address is not enough as there are other issues such as subnets and gateways. But dosen't the socket interface take care of all this I ask this because there are no functions in sockets that take parameters such as subnet mask's and gateways etc. Any help would be gladly accepted
: : Thanks
: : Rohit
: : :
: :
: :
:
:
: Right, all you need to supply is an IP address and a port number.
:
: If the receiving machine (the server) has a router/firewall, it needs to have the port open that you wish to use to listen for connection attempts from the client.
:
:
: To understand recursive, first you need to understand recursive
:
:So I was right all the way, thanks a lot and one more question is there a way to programmatically configure the firewall or router so that it lets packets of that are coming through my port pass through or will I have to manually configure the firewall or the router or are there some ports that are considered safe or are checked and if the packets are innocent enough they allow them to pass thrrough.
Thanks a lot
Rohit

: : : : : : : This is probably too simple a problem but I am not able to find any
: : : : : : : answers to it.
: : : : : : : I was having an instant conversation with somebody using yahoo
: : : : : : : messenger but could not ping to that persons machine and neither could
: : : : : : : he ping to mine, is this possible? And if it is please tell me how to
: : : : : : : solve this problem?
: : : : : : : Thanks a lot
: : : : : : : Rohit
: : : : : : :
: : : : : : :
: : : : : : :
: : : : : : :
: : : : : :
: : : : : : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: : : : : :
: : : : : : The firewall needs to be configured to accept echo requests.
: : : : : :
: : : : : :
: : : : : : To understand recursive, first you need to understand recursive
: : : : : :
: : : : : :
: : : : : Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: : : : : Thanks a lot
: : : : : Rohit
: : : : :
: : : :
: : : :
: : : : Most likely a firewall.
: : : : To understand recursive, first you need to understand recursive
: : :
: : : : Actually I have made a simple program using winsock to send a message from one computer to another. The client sends a message and the server recieves it and displays it using a messagebox. My friends keep telling me that supplying the IP address is not enough as there are other issues such as subnets and gateways. But dosen't the socket interface take care of all this I ask this because there are no functions in sockets that take parameters such as subnet mask's and gateways etc. Any help would be gladly accepted
: : : Thanks
: : : Rohit
: : : :
: : :
: : :
: :
: :
: : Right, all you need to supply is an IP address and a port number.
: :
: : If the receiving machine (the server) has a router/firewall, it needs to have the port open that you wish to use to listen for connection attempts from the client.
: :
: :
: : To understand recursive, first you need to understand recursive
: :
: :So I was right all the way, thanks a lot and one more question is there a way to programmatically configure the firewall or router so that it lets packets of that are coming through my port pass through or will I have to manually configure the firewall or the router or are there some ports that are considered safe or are checked and if the packets are innocent enough they allow them to pass thrrough.
: Thanks a lot
: Rohit
:
:



Nope, there is no router config 'API' since all firewalls/routers are different and use their own interface, so you'll have to manually configure it.

Some firewall programs will alert you when a program is trying to access the outside world through some port and make it easy for you to allow it, but with most of them you are stuck doing your own port-forwarding.


To understand recursive, first you need to understand recursive

: : : : : : : : This is probably too simple a problem but I am not able to find any
: : : : : : : : answers to it.
: : : : : : : : I was having an instant conversation with somebody using yahoo
: : : : : : : : messenger but could not ping to that persons machine and neither could
: : : : : : : : he ping to mine, is this possible? And if it is please tell me how to
: : : : : : : : solve this problem?
: : : : : : : : Thanks a lot
: : : : : : : : Rohit
: : : : : : : :
: : : : : : : :
: : : : : : : :
: : : : : : : :
: : : : : : :
: : : : : : : If someone is using a router or other firewall that blocks echo requests then it is not possible to ping their machine.
: : : : : : :
: : : : : : : The firewall needs to be configured to accept echo requests.
: : : : : : :
: : : : : : :
: : : : : : : To understand recursive, first you need to understand recursive
: : : : : : :
: : : : : : :
: : : : : : Thanks a lot. I keep getting a message "request timed out". Is this because of a firewall, and if there is some other reason then please tell me about it.
: : : : : : Thanks a lot
: : : : : : Rohit
: : : : : :
: : : : :
: : : : :
: : : : : Most likely a firewall.
: : : : : To understand recursive, first you need to understand recursive
: : : :
: : : : : Actually I have made a simple program using winsock to send a message from one computer to another. The client sends a message and the server recieves it and displays it using a messagebox. My friends keep telling me that supplying the IP address is not enough as there are other issues such as subnets and gateways. But dosen't the socket interface take care of all this I ask this because there are no functions in sockets that take parameters such as subnet mask's and gateways etc. Any help would be gladly accepted
: : : : Thanks
: : : : Rohit
: : : : :
: : : :
: : : :
: : :
: : :
: : : Right, all you need to supply is an IP address and a port number.
: : :
: : : If the receiving machine (the server) has a router/firewall, it needs to have the port open that you wish to use to listen for connection attempts from the client.
: : :
: : :
: : : To understand recursive, first you need to understand recursive
: : :
: : :So I was right all the way, thanks a lot and one more question is there a way to programmatically configure the firewall or router so that it lets packets of that are coming through my port pass through or will I have to manually configure the firewall or the router or are there some ports that are considered safe or are checked and if the packets are innocent enough they allow them to pass thrrough.
: : Thanks a lot
: : Rohit
: :
: :
:
:
:
: Nope, there is no router config 'API' since all firewalls/routers are different and use their own interface, so you'll have to manually configure it.
:
: Some firewall programs will alert you when a program is trying to access the outside world through some port and make it easy for you to allow it, but with most of them you are stuck doing your own port-forwarding.
:
:
: To understand recursive, first you need to understand recursive
:
: But I had read that all messengers such as yahoo and msn are built using soket programming. Then how do they get past this firewall problem cause they would be operating like this only.
Rohit

: : Some firewall programs will alert you when a program is trying to access the outside world through some port and make it easy for you to allow it, but with most of them you are stuck doing your own port-forwarding.
: :
: :
: : To understand recursive, first you need to understand recursive
: :
: : But I had read that all messengers such as yahoo and msn are built using soket programming. Then how do they get past this firewall problem cause they would be operating like this only.
: Rohit
:

Sorry, looks like what I typed there wasn't exactly what I meant.

If you are running a server, it's waiting for connections from the outside world. You will need to configure your firewall to allow connections on that port so your server can receive the incoming requests.

If you are running a client, it's initiating the connections to the outside world so most firewalls will simply let it work to make life easy for you. Some firewalls, like ZoneAlarm will alert you that some program on your computer is trying to access the outside world and give you an option to allow or deny it, but most simply allow it.


Yahoo and MSN are clients, not servers, so they can easily connect to the main server without any configuration by you most of the time. They can sometimes act as servers (during file transfer and direct-connect for example) and sometimes have problems with firewalls during those times.




To understand recursive, first you need to understand recursive

: : : Some firewall programs will alert you when a program is trying to access the outside world through some port and make it easy for you to allow it, but with most of them you are stuck doing your own port-forwarding.
: : :
: : :
: : : To understand recursive, first you need to understand recursive
: : :
: : : But I had read that all messengers such as yahoo and msn are built using soket programming. Then how do they get past this firewall problem cause they would be operating like this only.
: : Rohit
: :
:
: Sorry, looks like what I typed there wasn't exactly what I meant.
:
: If you are running a server, it's waiting for connections from the outside world. You will need to configure your firewall to allow connections on that port so your server can receive the incoming requests.
:
: If you are running a client, it's initiating the connections to the outside world so most firewalls will simply let it work to make life easy for you. Some firewalls, like ZoneAlarm will alert you that some program on your computer is trying to access the outside world and give you an option to allow or deny it, but most simply allow it.
:
:
: Yahoo and MSN are clients, not servers, so they can easily connect to the main server without any configuration by you most of the time. They can sometimes act as servers (during file transfer and direct-connect for example) and sometimes have problems with firewalls during those times.
:
:
:
:
: To understand recursive, first you need to understand recursive
:
: Ok so just to be cler. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send' functions would work is that correct?

: : : Some firewall programs will alert you when a program is trying to access the outside world through some port and make it easy for you to allow it, but with most of them you are stuck doing your own port-forwarding.
: : :
: : :
: : : To understand recursive, first you need to understand recursive
: : :
: : : But I had read that all messengers such as yahoo and msn are built using soket programming. Then how do they get past this firewall problem cause they would be operating like this only.
: : Rohit
: :
:
: Sorry, looks like what I typed there wasn't exactly what I meant.
:
: If you are running a server, it's waiting for connections from the outside world. You will need to configure your firewall to allow connections on that port so your server can receive the incoming requests.
:
: If you are running a client, it's initiating the connections to the outside world so most firewalls will simply let it work to make life easy for you. Some firewalls, like ZoneAlarm will alert you that some program on your computer is trying to access the outside world and give you an option to allow or deny it, but most simply allow it.
:
:
: Yahoo and MSN are clients, not servers, so they can easily connect to the main server without any configuration by you most of the time. They can sometimes act as servers (during file transfer and direct-connect for example) and sometimes have problems with firewalls during those times.
:
:
:
:
: To understand recursive, first you need to understand recursive
:
: Ok so just to be clear. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send()' functions would work is that correct?

: : Ok so just to be clear. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send()' functions would work is that correct?
:
:


Not exactly.

If you're running a server behind a firewall, anything trying to connect to it should be blocked by the firewall.

If you're running a client behind a firewall, it should be able to send outbound signals. If you make an outbound connection from your client, you should be able to receive back signals on that connection. Since the connection was initiated from behind the firewall on your machine, the firewall should allow transfer back and forth through that socket's port.


To understand recursive, first you need to understand recursive

: : : Ok so just to be clear. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send()' functions would work is that correct?
: :
: :
:
:
: Not exactly.
:
: If you're running a server behind a firewall, anything trying to connect to it should be blocked by the firewall.
:
: If you're running a client behind a firewall, it should be able to send outbound signals. If you make an outbound connection from your client, you should be able to receive back signals on that connection. Since the connection was initiated from behind the firewall on your machine, the firewall should allow transfer back and forth through that socket's port.
:
:
: To understand recursive, first you need to understand recursive
:
: Ok, now I am begining to understand how yahoo and msn resolve this problem. This is what I understood. Yahoo and all have their clients running on our desktop PC's and their messenger server running on some remote machine and when we sign into their messenger service we are actually requesting a connection to be made with such a server. Now as the request for connection has been made thru our machine even if we are behind a firewall all the sends and recieves would work because it is us who initiated the connection right?

: : : : Ok so just to be clear. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send()' functions would work is that correct?
: : :
: : :
: :
: :
: : Not exactly.
: :
: : If you're running a server behind a firewall, anything trying to connect to it should be blocked by the firewall.
: :
: : If you're running a client behind a firewall, it should be able to send outbound signals. If you make an outbound connection from your client, you should be able to receive back signals on that connection. Since the connection was initiated from behind the firewall on your machine, the firewall should allow transfer back and forth through that socket's port.
: :
: :
: : To understand recursive, first you need to understand recursive
: :
: : Ok, now I am begining to understand how yahoo and msn resolve this problem. This is what I understood. Yahoo and all have their clients running on our desktop PC's and their messenger server running on some remote machine and when we sign into their messenger service we are actually requesting a connection to be made with such a server. Now as the request for connection has been made thru our machine even if we are behind a firewall all the sends and recieves would work because it is us who initiated the connection right?
:
:


Exactly.


When you chat on an IM program with your friend, your chat is actually going to the server and being relayed to your friend. You are not directly connectd to him. You can verify this by checking your machine's connections while you are chatting... you will see that you are only connected to the main chat server, and not to your friend's computer.


To understand recursive, first you need to understand recursive

: : : : : Ok so just to be clear. If a socket program is running on a system behind a firewall then all the 'recv()' functions would work but none of the 'send()' functions would work is that correct?
: : : :
: : : :
: : :
: : :
: : : Not exactly.
: : :
: : : If you're running a server behind a firewall, anything trying to connect to it should be blocked by the firewall.
: : :
: : : If you're running a client behind a firewall, it should be able to send outbound signals. If you make an outbound connection from your client, you should be able to receive back signals on that connection. Since the connection was initiated from behind the firewall on your machine, the firewall should allow transfer back and forth through that socket's port.
: : :
: : :
: : : To understand recursive, first you need to understand recursive
: : :
: : : Ok, now I am begining to understand how yahoo and msn resolve this problem. This is what I understood. Yahoo and all have their clients running on our desktop PC's and their messenger server running on some remote machine and when we sign into their messenger service we are actually requesting a connection to be made with such a server. Now as the request for connection has been made thru our machine even if we are behind a firewall all the sends and recieves would work because it is us who initiated the connection right?
: :
: :
:
:
: Exactly.
:
:
: When you chat on an IM program with your friend, your chat is actually going to the server and being relayed to your friend. You are not directly connectd to him. You can verify this by checking your machine's connections while you are chatting... you will see that you are only connected to the main chat server, and not to your friend's computer.
:
:
: To understand recursive, first you need to understand recursive
:
: Wow, now its crystal clear. These people and yahoo and microsoft really know what they are doing. I was thinking that a firewall protects a system by blocking certain ports. Isn't it possible to bypass this problem by making a connection through some commonly used port such as the FTP port or the HTTP port. I know this is not right to use ports that are used by such applications but is it possible to solve this problem like this.