Modem 3G - Two different IPs - networking

I just saw something I never have seen before.
I got a new SIM card from Nextel (communication company). I tried to use it on a 3G modem E3131, where I had a successful case before with VIVO (another communication company). Now it is different, instead to have only an external IP, I'm getting two different IPs.
For example:
When I go to some service like whatismyip.com, I see an IP 200.xxx.xxx.xxx, but when I check it out on ipconfig /all, I see another IP 10.xxx.xxx.xxx.
My problem is I can't connect to my app from another computer because there's no port redirection to internal IP. I must connect to some specific ports.
Does anyone know how to fix this problem?
Thanks in advance!

Related

Local Area Network Configuration Question

Comcast installed a Juniper Universal Access Router ACX1100, I plugged our switch to the port that the technician told us that is in/out port. But nothing happened, after reading and asking I was told that I need a managed switch to be configured with the gateway IP and that IP is a /29. That's where I got lost. According to him there are 6 usable IP's.
example:
Gateway: 192.168.120.161/29
Usable Range: 192.168.120.162 - 192.168.120.167
One of my multiple questions is what hardware do I need to be able to connect my PC's?, I configured a managed switch, but when I connect my laptop to it I get Unidentified Network and No Internet Connection.
I have been reading and I think I need a VPN with DHCP server integrated.
If some one can help me I'll appreciate it.
/29 is the subnet mask, it can also be expressed as 255.255.255.248. Basically it defines which part of the IP is the network ID and which part of IP is the host ID.
I think in order to accurate assess your situation, we need to know exactly what kind of configuration you set on the managed switch you purchased, also which managed switch did you purchase?
Also currently on your laptop's NIC, what IP is assigned on there?
Either on your old unmanaged switch or on the managed switch, you can try assigning one of the addresses from the /29 block that the technician told you about statically. And the default-gateway with the addresses you posted in your question.

Using WAN IP to connect to a device connected to router

I have a router (belkin) with many devices connected.
I ran a application on one my devices and the application assigned a port number for remote connection.
Now for me access this device i tried doing something like:
wanipaddress:port
But unable to connect. I am not sure if the router can be used to accomplish the above.
Any suggestions on how to achieve the above?
P.S my router assigned unique LAN IP to all the devices.
I achieved the following using Port Forwarding mechanism. A port forward is a way of making a computer on your home or business network accessible to computers on the internet, even though they are behind a router.
I found the following tutorial to be useful:

How to Find My Proper Ip Address to Connect to Another Computer Remotely

My friend wanted to connect to my computer using Remote Desktop Connection. But the problem is I am confused what my Ip address is.
My computer is connected to the internet via router via broadband internet network. My ip address is dynamic.
Here, my main purpose is not only the remote connection but also learning how dynamic ip connect to another pc.
I searched for ip address on Google. They show me an ip address. But I think it is not mine, it's related with the router or broadband network. I also find a WAN ip (it is different from that i found on google) on router settings. It did't work.
I used Team Viewer. It worked perfectly. But I want to do that manually because I am going to make a multiplayer game on GM8.
It will helpful if someone explain about ip and port forwarding.
Teamviewer is a great tool, but uses different techniques than what you plan to do. Teamviewer always uses an outgoing connection and use a mediator on the Internet to connect you and the other PC.
You should ask your Internet provider if he technically enables you to be reachable from the outside Internet. Often this is not possible at all, even if you configure your router the correct way.
When you ask this you can ask him if you have a static IP.
It seems you are not aware of basics of IP networking, so I'd strongly advise against trying this on your router as wrong settings would render it useless. But here's for your information how port forwarding and IP Address and dynamic DNS can be used to solve your problem.
Basically your ISP is likely to give you a router having an IP address. If this IP address is a global IP address, it is possible to connect to this IP from outside. How do you find out whether your IP address is global? Look for your WAN IP address setting. If it is in 10.x.x.x or 192.168.x.x range, it's unlikely to be global and in that case it might not be possible to connect to your computer from outside - without help of a third server (some kind of a registration server, where you connect and register your application). The Registration server would determine your globally visible IP address and then convey it to another Application who is interested in connecting to it. This is somewhat complicated to make it work (but if you intend to make a game - this is something you'd have to do regardless). This is mostly how software like TeamViewer would work.
If you have a global IP address - it means it can technically be reached from anywhere in the world. In that case you could use port forwarding to make things work for you. Port forwarding works basically as follows - You expose a certain port (on TCP) to external world - say 8000 and then you make a setting like following on your router.
<TCP>-<RouterIP>-8000 --> <TCP>-<Your LAN IP><Your application Port>
(You can find you lan ip using ipconfig on windows or ifconfig on Linux).
Now all connections coming to port 8000 would be directed to your application. You might want to do it on UDP as well and the protocol above would change. That is how you 'open' a few ports to be accessible from outside, configure them on your router and then run corresponding applications on your network.
There's another thing called dynamic DNS, where the IP address you use if it is dynamic (and global) can be registered with a Dynamic DNS server so that you don't have to know and remember the current WAN IP Address. But that can be for later.
Hope that helps.

Connecting Veency on Iphone from another network

I installed Veency Server on my old Iphone 3GS. I can connect to it from my other devices in local network, using its 192.168.2.xxx adress, but i cant connect from another network. I know that my router uses NAT so i tried port forwarding for ports 5500,5900 and 5800, then i tried to forward all ports in range 0:7000 but none of them seemed to work. What can i do ?
Thanks a million in advance.
Shouldn't be too complicated.
Set a DHCP reservation in your router for the device.
Forward the VNC port (Usually 5900) to the IP you set.
If you don't have a static external IP, get something like No-IP or DynDNS so you can have an unchanging URL to connect to.
That's about it, it's no different than making any other service external.
You should know that this will not be secure, and very easy for a man in the middle attack to happen.

Automatically detect a new computer connected to the network

Is there an elegant way to make a program detect a new computer that is connected to the network?
I would like my program to "auto-sense" a new computer being connected on the network (they're on the same network). Like a USB device being connected to the computer.
What I'm doing now is to save a list of all computers in the network from time to time. Another approach is to PING all available IPs on the subnet.
Are there any other elegant approaches?
Thanks!
Listening for ARP requests is the canonical way to do this. Independent of DHCP or not, any connected computer that wishes to communicate with the outside world will have to make an ARP request for the address of the default router. This request will go out as a broadcast, and contain the source interface's MAC and IP adresses.
If the other computer uses DHCP, it will make an ARP request for it's own address as part of duplicate address detection, which is also a broadcast you can snoop on.
(This works more or less the same way for IPv6, except you need to look for neighbor discovery or router soliciation packets instead.)
Like the answer alluded to, if you have a switch to which you can telnet or use SNMP on, you can extract the MAC table. That will give you a list of MAC adresses on each port in the switch. If you want the IP addresses however, you still need to listen for ARP:s.
On the other hand, if you have access to the default gateway on the network, you can also look at the ARP table there. That will give you MAC and IP addresses for anyone that has recently (for different values of recently...) communicated with it.
If you have a managed switch of some kind, you could probably connect to that, that would be a fairly elegant method.
If you're on a domain, you can can get a list of all the machines joined to the domain from the domain controller.
Failing that, all I can think of is either a challenge/response thing (e.g. pinging them) or by detecting traffic sent from them (see this question maybe as a starting point?), neither of which strike me as an elegant approach.

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