After establishing a PPP connection using rasdial (making a dial-up call), how do I get the 'server ip' address that is given to me. It's usually a local ip, but I cannot seem to get it when I do an ipconfig.
However I can see this IP address, if I right click on the connection and select status.
This question has been asked in the past, but by .NET and C# users and their solution is using a certain available library, which I don't have.
Does anyone know how to obtain the PPP server ip? I need that IP address to initiate an FTP traffic with the modem.
I established the connection this way :
system (rasdial [connection_name]); # in perl.
Thanks!
I think your best best is to hook into the Windows API calls with Win32::API. You probably want to start with RasEnumConnections.
Related
I have been trying to learn socket programming in C++ and got some progress for the basics. But I understood that basics are not fundamentals.
One of those fundamentals is about the question which is stated in the title. Lets say I have two separate applications running on the same computer. One of them has a server socket and the other one has a client.
When the server gets an IP address automatically, how can client find the server? Do I have to assign an IP address that is known by the client? In that case, maybe that IP address is not available on the network.
Or can client find and connect to the server by sone kind of name or id?
Have the server bind to all interfaces and have the client lookup 'localhost' by name; it's resolved locally, (ie. no external DNS service required), to an IP address stored in a 'hosts' file, and is set by default to 127.0.0.1
Google 'hosts file'
The IP address of any server in the same host is 127.0.0.1 unless the server has bound to a specific, different IP address. As #MartinJames points out, you can use 'localhost' as the hostname for that, except on certain broken Linux distributions.
For example, when you make an ssh connection, you are connected to port 22. What happens then? On a very high level brief overview, I know that if port 22 is open on the other end and if you can authenticate to it as a certain user, then you get a shell on that machine.
But I don't understand how ports tie into this model of services and connections to different services from remote machines? Why is there a need for so many specific ports running specific services? And what exactly happens when you try to connect to a port?
I hope this question isn't too confusing due to my naive understanding. Thanks.
Imagine your server as a house with 65536 doors. If you want to visit family "HTTP", you go to door 80. If you were to visit family "SMTP", you would visit door no. 25.
Technically, a port is just one of multiple possible endpoints for outgoing/incomming connections. Many of the port numbers are assigned to certain services by convention.
Opening/establishing a connection means (when the transport protocol is TCP, which are most of the “classical” services like HTTP, SMTP, etc.) that you are performing a TCP handshake. With UDP (used for things like streaming and VoIP), there's no handshake.
Unless you want to understand the deeper voodoo of IP networks, you could just say, that's about it. Nothing overly special.
TCP-IP ports on your machine are essentially a mechanism to get messages to the right endpoints.
Each of the possible 65536 ports (16 total bits) fall under certain categories as designated by the Internet Assigned Numbers Authority (IANA).
But I don't understand how ports tie into this model of services and
connections to different services from remote machines? Why is there a
need for so many specific ports running specific services?
...
And what exactly happens when you try to connect to a port?
Think of it this way: How many applications on your computer communicate with other machines? Web browser, e-mail client, SSH client, online games, etc. Not to mention all of the stuff running under the hood.
Now think: how many physical ports do you have on your machine? Most desktop machines have one. Occasionally two or three. If a single application had to take complete control over your network interface nothing else would be able to use it! So TCP ports are a way of turning 1 connection into 65536 connections.
For example, when you make an ssh connection, you are connected to
port 22. What happens then?
Think of it like sending a package. Your SSH client in front of you needs to send information to a process running on the other machine. So you supply the destination address in the form of "user#[ip or hostname]" (so that it knows which machine on the network to send it to), and "port 22" (so it gets to the right application running on the machine). Your application then packs up a TCP parcel and stamps a destination and a return address and sends it to the network.
The network finds the destination computer and delivers the package. So now it's at the right machine, but it still needs to get to the right application. What do you think would happen if your SSH packet got delivered to an e-mail client? That's what the port number is for. It effectively tells your computer's local TCP mailman where to make the final delivery. Then the application does whatever it needs to with the data (such as verify authentication) and sends a response packet using your machine's return address. The back and forth continues as long as the connection is active.
Hope that helps. :)
The port is meant to allow applications on TCP/IP to exchange data. Each machine on the internet has one single address which is its IP. The port allows different applications on one machine to send and receive data with multiple servers on the network/internet. Common application like ftp and http servers communicate on default ports like 21 and 80 unless network administrators change those default ports for security reasons
Can anyone tell me how to get the machine name where the server is hosted
i know its IP address.
I know it can be sent from the server itself but still was curious about how it could be done from the Iphone.
Thnks in advance
Regards
Nitesh
I assume you're trying to do a reverse DNS lookup. There are some web-based services which you could use from an iPhone. For example: http://www.ipchecking.com/
However, if the IP address is being used by more than one server, this may not give you helpful results. It's also possible that the service you're looking for on the server could respond only to a name different than the one listed.
I have a Laptop, with msSql sever 2005, and it is connected to my Wifi router which gets the internet. So My laptop get connected to internet. But I need to access my msSql Sever from internet to connect my webpage which I made using ASP.Net.
Please Help me... And please give a solution for this...
You'll need your IP adress to connect, then open the SQL-Port in your router. (default is 3306)
When you connect to the server just use your current ip adress.
Maybe you want a static ip or something like http://dyndns.org
you want to write web service and host that service in sql machine
First setup a static IP address on your laptop and after that you need to set up port forwarding in your router. This process differs slightly depending on your routers manufacturer and model.
After this is set up properly make sure that SQL Servers port is open on your laptops firewall.
By using Dynamic DNS you can point to your possibly changing IP address with static name so you don't have to change this constantly in your connection string.
Recently we got a new server at the office purely for testing purposes. It is set up so that we can access it from any computer.
However today our ip got blocked from one of our other sites saying that our ip has been suspected of having a virus that sends spam emails. we learned this from the cbl http://cbl.abuseat.org/
So of course we turned the server off to stop this. The problem is the server must be on to continue developing our application and to access the database that is installed on it. Our normal admin is on vacation and is unreachable, and the rest of us are idiots(me included) in this area.
We believe that the best solution is to remove it from connecting to the internet but still access it on the lan. If that is a valid solution how would this be done or is there a better way? say blocking specified ports or whatever.
I assume that this server is behind a router? You should be able to block WAN connections to the server on the router and still leave it open to accepting LAN connection. Or you could restrict the IPs that can connect to the server to the development machines on the network.