I'm learning about Networks and recently found out that the SCP protocol is used to edit files on some other computer. Now the thing is that the other computer should be on the same network. So I was curious about how to edit files across different networks?
Additional information: In my college we have computer labs. Each lab has exactly one switch. All the computers in a particular lab are connected to the switch. Also all of the labs have Internet connection. So if I want to edit a file using VIM on a computer that my friend is on but he is on a different lab, then how can I do it?
Application-level protocols like SSH and HTTP use an underlying TCP/IP connection; they work regardless of the subnet (barring extended networking features like firewalls, packet filters, network proxies, etc.)
So, if your friend's computer is reachable via the Internet, or just the local lab network, and you have the IP address / DNS name of his computer, and the corresponding port (22 for SSH / SCP) is not blocked, and you have a login on his computer, you can remotely edit files there.
If your end goal is remote editing, I would approach this via these steps, each building on top of the previous one:
ping othercomputer
ssh user#othercomputer
In Vim: :edit scp://user#othercomputer/path/to/file
Related
I am sorry, I dont know if this question is already asked (afaik this wasnt asked based on my search results). I have a computer running a software that needs license from a server in my company's domain. For pulling the license, I need to connect to the company network. Also there is a hardware setup in our company which is not integrated to the network. And I need to process some data from the hardware, and the data has to be shared with the software. So, I make two connections, one ethernet connection to the hardware and other wireless for using the software's license. I tried accessing the data from the hardware in the software through hardware's IP address. The problem is, there is another computer in our company from another location sharing the same IP as the Hardware, and the software tries retrieving the data from that computer and fails. I am sorry, if this is priliminary and I am not a networking person.
Simply put, one of the two systems need to change its IP address.
The alternatives are usually too complex and error prone, and their viability depends on the particularity of your environment:
Use arp command to force your PC IP-Mac mapping
Put a router in front of your hardware that does port forwarding
Use VLANs
I'm creating a Hyper-V lab network on my machine and wanted them to have internet access as well as communication to each other in the lab. I used Powershell to create a new NAT switch for the ethernet adapter and all works as expected. My lab machines are on the same subnet and can talk to each other and have external internet access.
My question is how can I ensure that my lab machines can't affect my home machines? I can ping other machines in my home network from lab machines which concerns me that my lab could possibly send out DHCP IPs, other settings, or viruses to my home machines.
Sorry new to this and want to learn how to ensure the separation of the two networks? Or is the only real way to separate the two is to only use the NAT switch when I absolutely need internet?
Thanks!
By having a proper router somewhere in front and putting the home network under the same style of NAT setup. That will mean you can not reach the home network from the lab.
That said, you do not ahve to worry about DHCP - DHCP is only local broadcast domain and does not cross routing (unless you use a forwarder which has to be excplicitly set up in the target network).
I'm using a Cisco client to connect to a VPN but also using Synergy (Symless) to connect to the machine. It works fine initially but will drop out after machine sleep (or sometimes seemingly randomly), then I have to restart the VPN connection. Not the end of the world, but it is irritating.
Are there any config changes I can do to Networks settings, VPN or Synergy to stop this dropping out?
Found this which I hope will fix it.
https://blog.lan-tech.ca/2013/02/21/access-local-and-vpn-network-simultaneously/
"you just need to add the local devices to the windows routing tables so that it knows to access them when the VPN is active.
See the windows “route” command – E.G. route -p add MASK 255.0.0.0 METRIC IF
To help discover what you need to use, disconnect from your VPN, make sure you can connect to your local device, then run a “route print” show the current active routes and find your device. (generally in the IPv4 Route Table)
It will also list the ‘Metric’ to use, and at the top of the listing is the “Interface List” which lists the network interfaces on your system. You’ll need to figure out which one to use. For example, I know my system has a gigabit network adapter and in the list I see a “Intel(R) Gigabit Network Connection” – bingo – that’s it. The first column is the interface id, 49 in my case.
The “-p” option makes your configuration persistent – meaning that it will be there again next time you boot.
SO, as an example, let’s say I want a local network share at 192.168.1.43 to be accessible to my machine while connected to the VPN, so I would add the route like so:
route -p add 192.168.1.43 MASK 255.0.0.0 192.168.1.1 METRIC 15 IF 49
Now if I run route print, I see this new route in the list of persistent routes for IPv4.
I turn my VPN back on, and instead of the device ‘disappearing’ as it normally does, windows can still find it because it is in the persistent route list."
I'm trying to establish a TCP connection between a client machine and a guest VM running inside an ESXi server. The trick is that the guest VM has no network configured (intentionally). However the ESX server is on the network, so in theory it might be possible to bridge the gap with software.
Concretely, I'd like to eventually create a direct TCP connection from python code running on the client machine (I want to create an RPyC connection). However anything that results in ssh-like port tunneling would be breakthrough enough.
I'm theorizing that some combination of VMWare Tools, pysphere and obscure network adapters could be possible. But so far, my searches don't yield any result and my only ideas are either ugly (something like tunneling over file operations) and/or very error prone (basically, if I have to build a TCP stack, I know I'll be writing lots of bugs).
It's for a testing environment setup, not production; but I prefer stability over speed. I currently don't see much need for high throughput.
To summarize the setup:
Client machine (Windows/Linux, whatever works) with vmware tools installed
ESXi server (network accessible from client machine)
VMWare guest which has no NICs at all, but is accessible using vmware tools (must be Windows in my case, but a Linux solution is welcome for the sake completeness)
Any ideas and further reading suggestions would be awesome.
Thank you Internet, you are the best!
It is not clear the meaning of 'no NICs at all on guest'. If I can assume that, there is no physical NICs assigned for the guest is what is meant here. The solution is easy as a vmWare soft NIC can be provisioned for the guest VM and that will serve as the entry point to the guest netstack.
But if the soft NIC is also not available, i really wonder how and what can serve as the entry point to the netstack of guest, be it Linux/Windows. To my understanding, if thats what you meant, then you might need to make guest OS modifications to use a different door to access the guest netstack and to post/drain pkts from it. But again, when you do a proper implementation of this backdoor, it will become just another implementation of softNIC which vmware by default support. So, why not use that?
It's a bit late but a virtual serial port may be your friend. You can pick the serial port on the outer end via network or locally depending on your options. Than you can have some ppp stuff or your custom script on both ends to communicate. You could also run some tool to create a single socket from the serial link on the guest end if you want to avoid having a ppp interface but still need to tunnel a TCP connection for some application.
This should keep you safe when analyzing malicious code as long as it's not skynet :-) You still should do it with the permission of the sysadmin as you may be violating your company's rules by working around some security measurements.
If the VM 'intentionally' has no network configured, you can't connect to it over a network.
Your question embodies a contradiction in terms.
I am developing a networked application that runs on a few different computers on a LAN. One of the core needs is for the app to maintain a list of peers on the LAN with which it has communicated in the past, so that it can restore previous sessions. The naive solution would be to just remember the IP and store it in a table, but what happens when the IP of a peer changes?
Instead, I thought I'd store the hostname of the peers so even if the IP changes they will still be reachable via their hostname. (I know hostnames can change as well but that is good enough).
So my question is what exactly is needed to make hostname resolution work on a LAN with mixed Windows/Mac/Linux clients?
Without the use of a central authority the only reliable way to achieve this is through the use of zerconfiguration name resolution. This means that without a multicast router you will only be able to dynamically resolve peers on the same subnet as the resolving host. You could use something like bonjour for mac, netbios or ssdp for windows or avahi for linux but you can't assume that these are enabled. I may be overlooking some more popular protocols that perform this function well but I would personally throw together a quick udp broadcast name resolution protocol for your application. Take a look at these for some more ideas:
Zeroconf Name resolution
Universal local network name resolution method without DNS?
http://en.wikipedia.org/wiki/Zero_configuration_networking#Name_resolution
http://en.wikipedia.org/wiki/Broadcast_address#IP_networking
I would pick a specific udp port to listen on (lets say 12000) and then when you're ready to resolve hosts send a "hello" udp packet out to 255.255.255.255 on port 12000 and all of the other hosts on your network running your app should reply with a packet containing their hostname, possibly other information.