Member Avatar for zonar

Please help me out of this. I have a very simple scenario which is

1 windows machine which Im using as host
with the ip address of
gateway:
Dns:

my host machine is running on (linux) with NAT enable mode
its ifcfg-eth0 file reads as follows:
Ip address:
Gateway:
Dns:

That's it i haven't changed anything in "manage virtual networks".
The same goes for the two default virtual interface (vmnet0) and
(vmnet8).

I need to know that along with the missing pieces how could i go about
using NATTING for my guest machine. As i'm still not being able to ping
the internet?

Thanks

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  • Latest Post Latest Post by khess

Dani AI

Generated

Short diagnosis and where to look first: the VM’s NAT network must be on a different private subnet than the physical LAN, and the machine that runs the NAT must be the actual hypervisor/host. correctly flagged the overlapping-subnet problem, and was right to ask which box is acting as the host. Either switch the VM to bridged mode (guest joins the physical LAN) or ensure the NAT network is non‑overlapping and that the host is performing IP forwarding/NAT.

Host-side checks (hypervisor or manual NAT):

  • If using the hypervisor’s built-in NAT (vmnet8/Virtual Network Editor in VMware, or VirtualBox NAT), open the virtual network editor and verify the NAT subnet and DHCP range do not conflict with the physical LAN; restart the NAT service after changes.
  • If you are doing NAT on Linux yourself, enable forwarding and add a masquerade rule. Example (replace interface names and vm interface names before running):

echo 1 > /proc/sys/net/ipv4/ip_forward
sysctl -w net.ipv4.ip_forward=1

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -i vmnet8 -o eth0 -j ACCEPT
iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT

Guest-side checks and quick tests:

  • Confirm the guest’s default gateway is the virtual NAT gateway and DNS is reachable.
  • From the guest: ping the virtual gateway, then ping an external IP (for example 8.8.8.8) to separate routing vs DNS problems.
  • On the host: run tcpdump on the NAT interface to confirm guest packets arrive. Use traceroute to see where traffic stops.
  • Remember Windows guests often block ICMP; lack of ping alone does not prove no connectivity.

Quick troubleshooting checklist: pick one fix at a time—change VM network to bridged, or change the NAT subnet to a different private range, or enable/verify host ip_forward + iptables MASQUERADE. If the problem persists, capture and post the host’s ip addr / route -n / iptables -t nat -L -n and the guest’s ipconfig/ifconfig so specific routing or firewall blocks can be identified.

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Member Avatar for sloan31

It looks like you are using the same subnet for your real network and your virtual network...you would need to change one of them.

Member Avatar for khess

Both say "host" machine. Which one is host and which is guest?

Is there a reason you want to use NAT instead of Bridging?

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