How do you lookup the local hostname from an IPv6 address in Python?
I'm trying to diagnose network bandwidth hogs, and I'm using Wireshark to find which IPv6 addresses are using the most bandwidth, but it doesn't include any hostsnames, so I'm left with a CSV of IPv6 addresses and total bytes transmitted.
Note, I'm not talking about converting a generic IP to domain, since that only works for DNS, not your local network's hostnames.
The only command line tool I know for doing this is:
sudo nmap -sn 192.168.1.0/24
but that doesn't list IPv6 addresses.
This is what I found looking online, I'm sorry but i think that what you are lookin at isn't possible.
From WireShark Q&A:
What you're looking at are probably neighbor discovery packets, which
are sent to a special multicast address called "solicited node
multicast".
It's basically the replacement mechanism for ARP, which is not used
for IPv6 anymore.
Usually, if you need to find out where something is coming from you
should try to determine the MAC address of the source, and then log in
to your switches to find the port where that MAC address is connected.
There should be a command that will show you the MAC address table of
the switch. If you can find a port where only the MAC address in
question is listed you need to follow the cable from that port to the
device.
If you have more than one MAC address listed for a port it is usually
a connection to another switch. In that case you need to log in to the
switch it connects to and repeat your search.
Related
I am writing a socket program to create a simple server.
When I write ip = socket.gethostbyname(socket.gethostname()) and then I print ip it prints 127.0.1.1
Why does this keep happening?
My device is connected to a mobile hotspot connection still the ip address remains of a local host.
I am using ubuntu 19.04 OS
The problem is that a host has multiple interfaces. It is not a problem is you use a true DNS or a carefully handwritten /etc/host file because then the system will look there to find the translation. But depending on the configuration, the host name can be bound to all the available interfaces, including the loopback one. And gethostbyname returns the address of the first of those interfaces in its own order.
To make sure of that, you should use gethostbyname_ex which returns a list of all the interfaces, and you should find the hostspot connected one, in addition to the loopback one.
In documentation we can read:
"The IP of the outgoing IP address to use for the performing the request."
That is not clear for me. Anyone can explain with more details what is the purpose of bindaddress ?
The computer where Scrapy is running might have multiple network connections, each with their own unique IP network address (or addresses, plural). For example, a laptop might have a WiFi connection and a wired Ethernet connection. A larger server-class system might have several Ethernet connections. Even a system that has a single network connection might have multiple IP addresses, some for IPv4 and others for IPv6.
The bindaddress option can be used to tell Scrapy which one of those local IP addresses should be used as the source address on its outgoing requests.
If you don't specify which local address you want Scrapy to use, then Scrapy will let the system choose the address. That choice is usually the local address that the system thinks is "closest" to the destination address of the request. This would be the usual situation. Unless you have a particular need to use a specific source address, there's no reason to use the bindaddress option.
I am looking for an easy way to convert a MAC address to the corresponding IP address in a local network. In my case, there are only two devices: a very normal PC (192.168.0.1) and a scientific instrument which has an arbitrary IP address (192.168.0.xxx) hard coded in its ROM. The PC and the instrument are directly connected over a UDP socket with a CAT5 cable.
I know the MAC address of the instrument, but please assume that its IP address is unknown. I would like to write a C/C++ application which talks with the instrument using a socket connection. But I need to know the IP address before opening a socket (WinSock on Windows, sys/socket on OS X and Linux).
Currently I use a very dirty way as shown below.
Execute ping command ping 192.168.0.2 (NOTE: the instrument does not respond to ping)
Repeat this from 192.168.0.2 to 192.168.0.255
Execute arp -a to print a list of IP and MAC addresses
Find the known MAC address and the corresponding IP address from the list
I would like to know how to retrieve the IP address in a more sophisticated way. It will be very nice if I can use the same method on Mac, Linux and Windows machines.
As far as I know, I have to broadcast a ARP packet to the network in order to retrieve a MAC address from a known IP address. But I could not find a way to get an IP address from a MAC address.
There's no good, generic solution for this as it is the reverse of intended behavior. Lower level protocols are not supposed to need to be aware of higher layer ones, so operations at the MAC layer don't have any good way of finding out about IP addresses. And then you get into the situation you're in now. So you can either employ a hack like the code you already have, or you can tackle this from a different direction. Is there any non-code way to determine the IP address of the device before hand? Such as setting it explicitly or putting it in a configuration file for your app. Alternatively, can you have the device send out spurious ARP requests? The PC should update its ARP cache based off of incoming requests as well as responses to requests it made.
We had to do this a while back, but I don't think we got it working properly.
I don't have the API calls off-hand, but they're easy to find in the Windows API. That's what we used, so our solution wouldn't be portable to non-Windows systems.
In our case, we ran into the same hurdle--no easy translation. What we ended up having to do was get a list of all the NICs available, and then loop through each one trying to match our given MAC address against the MAC address obtained from the NIC structure.
Once we found a match, we looked up the IP address given to the NIC structure.
We kept on going to see if we found any other matches in order to log an error. It's a good thing we did, because I believe we did find it multiple times, and it wasn't due to a MAC address being cloned.
That's when we learned that this would be an even harder problem, and we decided to abandon the whole thing and stick to just IP addresses.
How about try the system command arp within c++
system("arp");
This gives you a IP-MAC translation table.
few days ago I was also facing this issue but after many struggle I got its solution below
How MAC to IP address converter tool works?
This MAC address converter can convert MAC address to IPv4 IP Address and convert MAC address to IPv6 IP Address, these internet protocol Addresses are very common to use. It takes MAC Address as input string and generates a query against given MAC to IP address and MAC conversion option like to MAC to IPV6 or MAC to IPV4 or both for MAC address conversion together. After this MAC conversion you can also revert MAC to IP conversion changes by using IPv6 to IPv4. Query generates an output response according to selected options.If you insert any invalid input produces an invalid input message response
I need to transfer data via pyzmq through two computers connected by an ethernet cable. I have already set up a script that runs on the same computer correctly, but I need to find the tcp address of the other computer in order to communicate. They both run Ubuntu 14.04. One of them should be a server processing requests while the other sends requests. How do I transfer data over tcp through ethernet? I simply need a way to find the address.
EDIT: (Clarification) I am running a behavioural study. I have a program called OpenSesame which runs in python and takes python scripts. I need a participant to be able to sit at a computer and be able to ask another person questions (specifically for help in a task). I need a server (using pyzmq preferably) to be connected by ethernet and communicate with that computer. It wrote a script. It works on the same computer, but not over ethernet. I need to find the address
Tcp is a protocol that uses an internet connection to Transfer data, through an IP address and specific port, you have to ensure that those ip directions are in the same range and uses the same port. For example: one pc 192.168.1.50 and another pc 192.168.1.60 in 502 port. The easiest way is using a Modem and set an statical address for each pc.
In the following link, you can find easily in which ip direction is connected your Computer. http://www.howtogeek.com/howto/17012/how-to-find-your-ip-address-in-ubuntu/
Maybe you could periodically send datagram message containing peer's ip address (or some other useful information) to broadcast address, to allow other peers to discover it. And after peer's address is dicovered you can estabish connection via ZeroMQ or other kind... connection. :)
Hi there sorry for disturbing you guys. But I read something in the Magazine about porting codes to IPV6 so i tried just changing this code (socket.AF_INET6, socket.SOCK_STREAM)
In python it works, but the problem is that the server does not display the client ip.
I expected it to display it like this. Got connection from ('127.0.0.1', 59815).
But for it , it messes up all thing and give me this (Got connection from ('::1', 59815, 0, 0)),
So if I ask were is the client IP here?. and what does the two last zeros(0, 0) really mean?. And what should i do to port my code to IPv6.? Thanks iam using python(geany)
So if I do this(socket.socket(socket.AF_INET6, socket.SOCK_STREAM)) will I have put my code to IPV6, o are there some other things I need to do thanks)
::1 is the IPv6 address for localhost, just like 127.0.0.1 is the IPv4 address for localhost. So you are seeing the client's IPv6 address.
The fields in the socket address are documented in the Python socket documentation. They are:
host
port
flowinfo
scope-id
Flowinfo and scope-id are new for IPv6. Flowinfo contains the Flow Label, which is specified in RFC 6437. If you don't know how to use it you can safely leave it at 0. The scope-id is used when an address is valid in multiple scopes. IPv6 link-local addresses for example are valid on every IPv6 interface, but routing them from one interface to another is not possible. So if you want to communicate with link-local addresses you have to specify which interface to use. The scope-id is the number of the interface.
When porting code to IPv6 you have to think about a few things. The socket handling you already have changed. You should also look at name resolving and use functions that support both IPv4 and IPv6 (i.e. don't use gethostbyname() but use getaddrinfo() etc.) And don't forget to allocate enough space when storing IP addresses. IPv6 addresses take up more space than IPv4 addresses.
PS: The IPy library provides very useful classes for dealing with IP addresses.