VMWare FUSION:- Routing between VMs (configured as Host-Only interfaces) not working

[Crazy4Iphone]

Hi Guys,

New to MAC and VMWare World overall.

Here's my problem:-

I have fired up 4 VMs on my Fusion, these are for my Checkpoint Lab Preps:-
1. Win 7 with IP 10.1.1.201/24 range
2. 2 x RedHat Linux VMs with 10.1.1.1/24 and 10.1.1.101/24
3. 1 x RedHat Linux VM with 10.2.2.0/24
The Virtual Adapters selected are HOST ONLY as I do not need Internet on these. As long as they talk to each other its fine.

Now when I created the last VM and placed it in 10.2.2.0/24 network in HOST ONLY, it completely stopped talking to all of the 10.1 VMs.
Here is what I have done so far in an attempt to get them talking:-
1.Changed Interface type to NAT and Bridged (even though I do not need it for my setup) NO CHANGE.
2.Rebooted the entire set of VMs. NO CHANGE.
3.Put the last VM from 10.2 range to 10.1 and everything started working.

My conclusion was that as FUSION has NO WAY of explicitly defining manual VMNET interfaces (apart from the standard 3), which is where I am stuck.

Is there a limit on HOST-ONLY option for the number of VMs? Also, Does anyone know if HOST ONLY supports routing by Default BETWEEN VMs?

I thought I would keep going further with all VMs in the same NET, but as expected, my lab is all broken and I cant go further

Need to know 2 Things:-
1. Have I done the right thing by putting all the VMs in HOST ONLY? Based on VMWAREs explanation I think I have. Anything that you guys can suggest that I have missed here which could be tried?
2. Is there a way to get an option of additional (manual) VMNETs in Fusion, the way we see it in Workstation? I tried searching on Google but all results show up for Workstation and not for Fusion.

[dariusd]

Hi Crazy4Iphone,

The "host only" network behaves like a single Ethernet segment.  Even though your two subnets are sharing the same segment, you'll need to configure IP forwarding somewhere for the two distinct subnets to be able to communicate.  There is nothing in the default network configuration of Mac OS or Fusion that will forward packets between distinct subnets on vmnet1.

You can create a mini router VM to do the forwarding, by attaching the router VM to the host-only network, configuring its network interface with an address for each subnet and enabling IPv4 forwarding.  A minimal installation of your favorite OS should suffice.

Alternatively, you may be able to have the host OS kernel do the forwarding by manually configuring  appropriate IPv4 alias addresses and subnet routes on the host's vmnet1  interface and setting the "net.inet.ip.forwarding" host sysctl to 1,  but make yourself aware of the implications if you choose to do this --  your "host only" network will also gain connectivity beyond the host  unless you firewall it!  (Disclaimer: I haven't actually tried this... it should work, but you will be fighting against the host OS's network management.)

Either way, you'll then want to make sure that each of your regular VMs is configured with an appropriate subnet route (or default route) pointing to the interface on its subnet that will do the packet forwarding for it, and that the router/host is configured with an address on each subnet and the correct subnet routes, and that IP forwarding is enabled on the router/host.

Hope this helps!

Cheers,

--

Darius

[Crazy4Iphone]

Thanks for that.

It wasn't a problem with VMware. Needed a bit of routing and some firewall rules.

I got distracted with the fact that local subnet works and hence it was a VM fault but it wasnt.

HOST ONLY interface type is good enough to not go on the internet and still talk within the VMs thanks

[Crazy4Iphone]

Fusion was fine Linux and checkpoint software was issue