How VM Name is resolved over the LAN Network? - virtual-machine

I have hosted a VM (Red Hat Linux) named test-vm on my Desktop machine (Windows) with a static IP address but I don't have any DNS entry for this static IP address.
Without having an entry in the client's host file, to my wonder the ping test-vm responds. How is this possible? How test-vm is resolved at other machines on our LAN Network without having a DNS entry for test-vm?
Regards,
Adil Khalil

I guess you are using vmware client in your windows desktop. In this case, the hostname is associated to your vmware virtual DNS. With a ping of broadcast in your network, your vmware virtual DNS is forwarding the ping to your VM Client.

Related

How to acquire Windows 10 Host IP from an ubuntu HyperV Virtual Machine

I have a server running on my windows machine and a hyper-v ubuntu VM
I am trying to test the frontend from my VM but I want to make requests to windows 10
host, how can I get the host's IP?
Go to Wired Connected -> Wired Settings and just copy the DNS IP

Connect Hyper-V VM from WSL (Ubuntu)

I have created a VM on Hyper-V with 2 Network Adapters.
NAT switch for static ip
External Switch (for access internet)
From my command line I was able to connect to the VM with the Nat Switch IP
but from WSL Bash I was not able to connect with IP NatSwitch, but able to connect with ExternalSwitch IP.
Why?
Unfortunately this is the expected behavior. (As of 29/01/2021)
WSL2 uses Hyper-V Virtual Switch, vEthernet (WSL) virtual network adapter, that is providing internal type Hyper-V network that is only accessible from the VM and the Host. The Hyper-V machine has a different virtual network adapter e.g. vEthernet (Default Switch). If that is set to internal that is a different NAT-ed network (subnet) not connected to the WSL one. It is like the Host having 3 NICs and one cable (Cable 1) going to WSL on a subnet that only exists on that adapter/cable and another cable (Cable2) going to Hyper-V guest with a very different subnet on that NIC.
On the other scenario the Hyper-V guest shares the subnet with the Host machine ("Same subnet as the 3rd cable/NIC.") so it is routed back to the VM. See red labels.
There is a workaround in this GitHub issue using port forwarding to Guest VM from WSL.

Proxying a port for Virtualbox NAT is inconvenient - can't I provide the host with an IP instead?

I want to be able to SSH into a VM Guest of Virtualbox where the guests are sharing a NAT Network.
LocalNat Portforwarding (See https://www.pythian.com/blog/test-lab-using-virtualbox-nat-networking/ Set Up Portforwarding) is inconvenient vs. having an IP address on the NAT for the host.
Port forwarding requires me to keep specifying the port, e.g. in scp -P 2222 from-file localhost: and it messes with SSH keys as localhost now has two host identities, my laptop and the VM's ssh-rsa key.
Rather than port-forward, is there not a way of just adding another IP for my Virtualbox host?
Thanks, Martin.
You can set up a host-only network in addition to the NAT network. A host-only network is a local network which can connect to both the host and to individual VMs. The host and the VMs can communicate with each other through it.
Using the virtualbox GUI, go to Virtualbox manager > File > Preferences > Network and set up a host-only network. Enable the DHCP server. You could use these settings:
host adapter address is 192.168.56.1
DHCP server address is 192.168.56.100
Both masks are 255.255.255.0
The server address range is 192.168.56.101-192.168.56.254
This gives you the addresses from ...56.2 through ...56.99 to use as static addresses. You can manually assign them to VM interfaces if you like.
After setting up this network, you should see a virtual interface on your host system with the correct IP address (the one assigned to the adapter).
Now, go to network settings for the VM. Add a new network adapter. Set "attached to" to the "host-only adapter", and the name to the host-only network that you set up earlier.
Start the VM. It should see the host-only adapter in addition to whatever adapters it was using before. If it's a modern operating system, it'll probably query the DHCP server and set up the interface on its own. Alternately, from inside the VM OS, you could manually assign static addresses to these interfaces.
You can assign a host-only adapter to a VM in addition to its existing NAT adapter. In the past I've had a windows VM and an Ubuntu Linux VM set up this way. Both VMs and the host had no trouble communicating with each other as well as the Internet.

Network issue between VMWare guest and windows host

I have a windows 7 host, on which I am also running a windows 7 virtual machine, essentially I'm trying to setup buildbot, the host runs the build master while the vmware virtual machine will run the build worker. The virtual machine network adapter is configured to host only. The virtual machine It has an ip address of 192.168.1.12, while the host has an ip address of 192.168.1.92. Both addresses are static IPs there's no DHCP involved
I can ping the host from the virtual machine, and I can ping the virtual machine from the host.
But when I try to get both the build master(host) and the build worker(vm) to communicate, nothing seems to happen. Looking at the twisted log in the vm I can see error messages along the lines of
"TCP connection failed to connect to host on ip 192.168.1.92:8999"
Note the buildbot.tac on the build worker(vm) has the ip address of the host (192.168.1.92) and the port on which to connect 8999
I have tried netstat -ano on both the host and the vm and I cannot see any connection between the two.
I have tried turning off the firewall inside the virtual machine, just in case, but no success there either
Any suggestions.

Why I can't use my physical ip to see my website after using NAT in Eucalyptus

I have two real machines.
One is responsible for NAT and IP redirect called NC2 and another is responsible for eucalyptus KVM established 3 virtual machine.
No doubt, the OS of machine which is responsible for eucalyptus is Linux.
The guest OS of virtual machines are Windows XP.
Each virtual machine is a web server which runs Tomcat
NC2 gives an private IP 192.168.0.3 to Linux server.
Linux server gives 3 IPs which are private class B to virtual machines.
For example, one of guest OS gained IP 172.16.1.5
Now I use NC2 to redirect a physical IP x.x.x.x to 172.16.1.5
Here is my problem:
I can use other PC ,outer IP, connect to the website which is established on 172.16.1.5 with IP x.x.x.x, but I can't use machine with IP 172.16.1.5 to connect to it's own website.
I turned off the firewall on 172.16.1.5, and it's able to connect to internet such as yahoo or amazon. But it just can't use x.x.x.x to connect to it's own website.
I tested other guest OS which are gained 172.16.x.x also not able to connect to x.x.x.x.
How can I do to make guest OS connect it's redirected physical address?
It look likes this is caused by a NAT issue called 'hairpin'. Here is the explanation:
Let machine A on a LAN have a private IP address 192.168.0.10.
Let NAT N translate A's private IP to public 77.33.45.67 for the WAN.
Some 'early/old' NATs take for granted that the translated address in only going to be used from the WAN. Therefore, they don't forward packets on the LAN having ip address = 77.33.45.67 and only let in and forward those with this ip address when they come from the WAN.
This problem is solved in more recent NATs which detect these situations and forward packets properly. This problem is sometime encountered in P2P systems.
If you are lucky, your NAT be may be reconfigured to enable usage of translated address on the LAN. If not, then you need a new NAT.