sorry my poor title but I don't know how to express my intention.
In ipv4 there are 2**32 addresses right?
and then if I send 1024 packets per second I could check all the devices of the internet in 1165 hours to create map of the internet. with it I want to make a topology of the internet
it's not that bad, if I go with multiple computers like raspberry pie it would be more faster.
if it's not me but somewhat organization or people and they have enough time, it could even scanning all the ports of all the devices of the internet..!
is my thought a daydream? or somebody already did it? please let me know! I'm curious
If you are interested in the actual physical location of an IP address, then there are many sources compiled already available, like the one here for free. Some are more accurate(commercial ones) than others.
If you just want to know if an IP address is alive or what services are available then you are out of luck as many of these "public" IP addresses are only accessible from whitelisted sources and/or heavily protected from folks like you trying to sniff around for profiling reasons.
If you would like to map out the topology of the Internet, you could get a view of the Autonomous Systems (collection of IP network addresses typically owned by ISPs or larger corporations) by looking at publicly accessible BGP looking glasses. BGP is the protocol that controls the routing of packets on the Internet. Please note that this is very dynamic and changes frequently due to the dynamic nature of path selection algorythms.
Related
My company just moved office to a new building and the Internet company came to install the internet (fiber). The problem is that the telco company installed the router in the basement of the building (which it happens to be the parking of the building also). That means that the internet router for my company is at the basement, wide in the open. The router has 3 free ports, that means that potentially anyone that walks-by at the parking can plug-in a laptop and get into our network (not only use the internet but try to hack into our file servers, etc...). We are a software company.
Did we try to get router upstairs? Yes but after several discussions with the telco company, it seems we have no choice with this setup. Therefore, does anyone recommend a good solution to protect our network? First thing comes to mind is to purchase a Firewall Hardware box and plug that inside our office from the internet cable that comes from the wall. Would that be the best solution? And if yes, any recommendations for a not too expensive firewall hardware? Thanks a lot.
As far as I'm aware, modern routers nowadays should already have port security features built-in. So, optimistically, you may not need to purchase a hardware firewall.
On the other hand, if you can afford to lock the router into a frame/cage, that's also a mean of physical access control. Installing a security camera near the router is another option.
One possible solution for your case is using packet filtering.
It is a firewall technique used to control network access by monitoring outgoing and incoming packets and allowing them to pass or halt based on the source and destination IP addresses, protocols and ports.
A product that can suit your needs is Ixia's PacketStack. Its packet filtering capabilities can be used without any packet loss, you can anipulate traffic anyway you want - deduplicate, stamp and trim. You can hide or overwrite sensitive or personally identifiable information before providing the data to analysis tools.
I am trying to create a setup for testing network equipment, and would like to use multiple (3) NICs in a single PC to produce traffic through an external device, i.e. a network switch. From one interface to another.
All of the tests are for IPv6 and ethernet. All NICs have link local and global IPv6 addresses with the same network/subnet prefix.
Atm. all packets are routed internally and never use the physical wire.
I see a lot of threads solving the problem for IPv4 using the net.ipv4.conf.all.accept_local parameter together with some routing table fixes. But I can't find a solution for IPv6.
Anyone know of a solution?
Need a basic direction in the following project.
There is a linux based controller doing some industrial control stuff.
The box is equipped with cellular modem and is capable to get online through cellular carrier. Cellular communication is used because controller is mostly installed where no cables or short range radio is available. Places where sun don't normally shine :)
The task is to allow internet clients to connect directly to the box for some basic control/monitoring stuff. The problem is connectivity - how clients will discover the box? - I'd like to have the box act as a server (if possible). Assuming that cellular carrier allows the box to get online doesn't necessarily mean that the box will get public IP so that anyone would be able to get connected. To my understanding the cellular network acts as a gateway from those who are working inside of it, and reaching someone in that network from outside isn't possible. Am I wrong? We are looking for a generic solution, not a solution around particular cellular provider. The controller is installed in different countries, we need to find the standard way to "webify" it.
The software (and hardware) in the box is ours, we can basically do anything, but I am looking for the right way to do it in order to avoid surprises with different providers later. BTW, the solution doesn't necessarily have to be technical, may be it's possible to buy a permanent IP's per box, or setup VPNs.. Which way should I dig to? What questions to ask?
Your ideas are welcome!
Your summary of the problem is basically correct. I've implemented several systems that do this, and the odds of success are good.
The way you tackle this will depend on the number of remote units you expect a single user to interact with. If each user will handle only one or two devices, it's plausible to implement the web server on the remote device. If each user handles many devices, consider centralising as much administration as possible. I've implemented this using Zenoss for data logging, and a custom control server.
If the web server sits on the remote device, you can either buy a SIM with a static IP, or use a proxy server. I recommend setting up a proxy server unless the number of devices is very small.
There are three options for SIMs:
Static IP with an address on the public Internet will be expensive, and negotiating the deal with each provider in each country will be irksome. No proxy server is required.
Private APN SIMs will give you the option of a static address, but in a private address range. Negotiation with the mobile network is still required, and you will require a proxy server to sit between the public Internet and the private address range,
Standard data SIMs will connect to the Internet through NAT. You can use these to host your service by opening a VPN connection (we used openvpn) to your server. You can now reach the devices directly by connecting to the same VPN, or through a proxy server.
If you use openvpn, here are some more tips:
Give each unit a public serial number, and a private key. Store these in the firmware of the unit, and in a central database. Put the public serial number on the outside of the unit. You can use an openvpn login script to ensure that a particular unit always appears at the correct IP address, which keeps the proxy configuration static.
You can control openvpn's bandwidth usage by adjusting its keepalive behaviour, and how often it renegotiates. Measure and tune this before a large deployment.
The NAT timeouts in the mobile networks are generally between 5 and 15 minutes. The device must send a packet to the server often enough to keep NAT alive.
Cheap SIM deals may be web only with limited ports.
Other tips:
GPRS modem firmware can (rarely) crash internally. If your hardware supports it, provide software with the ability to power cycle the modem.
Test your box in areas with poor coverage in your own country before you send out international shipments.
This is a typical problem with "mobile agent" appearing in different places or using different providers (in this case just one provider, but it's almost the same). Usually it's solved using some kind of home agent - a server that the mobile connects to and gives details about how to reach it or if it can't be reached directly then the home agent acts as a proxy.
Client always contact the home agent first and then if it is possible they contact the mobile or if it's not they use the server as a proxy.
In some cases dynamic dns might be sufficient in other you need real proxy/ façade.
There's a good book: Andrew S. Tanenbaum & Maarten van Steen :"Distributed Systems: Principles and Paradigms"
You can ask cellular provider to give you a SIM card with internet access and fixed IP address. Then you can host any server you like. Do not forget that you are dealing with limited bandwidth.
We're developing an embedded application, running on a standalone GPRS connected device (no operating system there). We are trying to get an IP address of domain name. I think that we should use some public DNS service, like Google DNS (8.8.8.8). The question is - what is the simplest request we should send to 8.8.8.8:53 in order to receive IP address of our domain?
Again, we can't use libresolve or any other similar libraries. We will make a simple TCP connection to port 53 of Google DNS, and will format our request ourselves.
I tried to understand RFC1053 myself, but failed. Too many words :)
I'm not a DNS expert in any way, but I thought that DNS generally use UDP rather than TCP?
Either way, here's a link to a page that describes the communication using less words that might be easier to understand than the RFC itself.
Also, even if you can't use the libresolve library itself, can't you look at an open source version of that library and use the code from one of those (assuming that the license is compatible with your work). Here's one from Apple that I found via google.
I need to store persistent reference to third party device on an arbitrary IP network where the IP address of the devices may be static or randomly assigned by DHCP. I don't control the devices on the network and I can't rely on DNS and other ad-hoc networking protocols existing or working with the devices.
So I have been instructed to investigate using hardware addresses and ARP. This will work but I don't want to duplicate code. The kernel must manage an ARP table. On Windows you can access it using GetIpNetTable etc.
I am hoping there is an API to answer these two questions:
How do I translate from IP to MAC address? (ARP)
How do I translate from MAC to IP address? (InARP)
If not then I may have to do it more manually:
How do I read the kernel's ARP table?
How do I add an entry if I have the determined a mapping myself?
/proc/net/arp
K
ARP tables tend to be fairly local and short-lived. If you examine the protocol, the real MAC addresses are generally only provided when the given IP address is in the local subnet.
Otherwise, the packet is forwarded to the local router, which is then responsible for forwarding it.
If you do "arp -g" on Windows or "arp -a" on UNIX, you'll see the table, but I don't think it will do you any good, due to the reasons mentioned above. That command and
That's really what DNS is for but, as you say, it may not be an option for you.
You may well have to write your own 'ARP' database at your application level.
As for ARP:
You could use system("/usr/bin/arp -option_of_choice"); and parse the output, but that's an ugly hack. -- Not my recommendation.
Take a look at /usr/include/linux/sockios.h -- At the SIOCGARP, SIOCDARP, and SIOCSARP details. Those are ioctls that you can perform to manage the ARP table on linux. Of course, you'll have to perform these ioctls on a socket fd.
Here's some examples: SIOCGARP examples
I'm sure you can find many other examples in several other languages as well. As I'm assuming that you're using C.
As for RARP:
A quote from the linux rarp manpage:
" This program is obsolete. From version 2.3, the Linux kernel no longer
contains RARP support. For a replacement RARP daemon, see ftp://ftp.demen-
tia.org/pub/net-tools"
So you'll have to install rarpd on the target system.