[Solved] Debian Guest not reachable from another NetworkPC

[Bassi2k]

Hi there...
i got stuck a little bit. Hope u can help me out...

I got my WinXP Host where VirtualBox runs with two debian VM (both lenny 2.6.26-2-686).
Both geht autoIP over Bridged-Adapter. (Perhaps there's the fault?)
At first I'd say that i dont have clue about network configuration @ll.

1.VM-Debian -> Inetconnection works fine... i can ping 2.VM-Debian and host XP too.
Also otherway round... host can ping both Debian.
I also can ping the PC of my sister...from all systems.

But if i go to her pc i just can ping my XP :/
so perhaps u can help an inexperienced networkguy :]

[baf]

Check the firewall in your XP. It is by default on and blocks ping.

[Bassi2k]

But if i go to her pc i just can ping my XP :/

as i said... XP is pingable... the VM-Guest Debian NOT
(XP-FW is OFF)

DHCP IP via Router... works fine

IP SisterPC -> 10.0.0.116

IP my XP Host -> 10.0.0.53
- VM 1.Main-Debian -> 10.0.0.69
- VM 2.Main-Debian -> 10.0.0.88

My suspicion is that my XP must route the ping to 10.0.0.69/...88 or am i wrong?

[Sasquatch]

First of all, are you pinging it using the computer name, or the IP address? Linux doesn't broadcast it's name over the network through NetBIOS like Windows does (very ugly what MS does).

[Bassi2k]

hey there...
i ping via IP-Adress...

for my understanding... pc 1 ->ping VM-Debian(on pc2) can't reach...
does the nic of pc2(my vmhost) check also ping/network-requests of it's VM-PCs not even just his own ip??

[Sasquatch]

If you use bridged, the Host firewall should not even see the data to and from the Guest. You can always check it's logs.

I suggest you take the whole network apart and test one thing at a time, going further each time something works. Take a good look on the VM settings, which NIC is used for bridged and which is used on the Host to connect to the network and internet. These must be the same (as you know, and probably already have configured, but check again to be safe). Also check the IP configuration on both Host and Guests. Check the default gateway too, that might be a problem later on.
Configure the network on the Guests, have both of them running and ping the Host from the Guest.
If that works, do the reverse, ping the Guests from the Host. That should work too.
Now ping the Guests from each other. If that works too, it's all fine up to this point.
Now ping a machine outside the Host, a second computer for example. If that replies properly, reverse the ping direction (second pc to Guests).

[Bassi2k]

Ok... then i'll check again... and post it here... perhaps i made a mistake somewhere...

Host IP-Config: DHCP
works fine... gets always 10.0.0.53

VM-Config:-> "default"
-Networkadapter: PCnet-Fast III
-Bridged Adapter
-(only choseable NIC) Broadcom NetXtreme Gigabit Ethernet

VM-Debian IFCONFIG set on DHCP.
works fine also.... gets always 10.0.0.69

Host ping WM-Debian works fine...
WM-Debian ping Host works fine too...

------

My Sisters PC IP-Config: DHCP
works fine too... gets always 10.0.0.116

SistersPC ping Host works fine...
Host pings SistersPC works fine too...

SistersPC ping WM-Debian: no answer
WM-Debian ping SistersPC works fine...

------
Win-Firewall on Host checked... it's OFF

[Sasquatch]

Now this is really strange. 10.0.0.116 cannot ping 10.0.0.69, but 10.0.0.69 can ping 10.0.0.116. Can you check the ARP cache of your sister's PC and compare it to your Host (open a command prompt and enter arp -a). It should get the ARP data from the Guest.

[Bassi2k]

mh tested on hostpc... arp -a
there's the ip 10.0.0.69...
ping still works

tested on Notebook (friend just tried to help me)
-> NO IP there... then PING -> arp -a again
-> IP is There, but no ping reply
-also the ip of our Proxy is there AFTER the ping

SistersPC
-> IP is there... but no Ping

really annoying

Edit.... mh or is there somethin from debian why i wont get a ping reply? ...-.- ah cancel this...cause i CAN ping debian from host.

[Sasquatch]

With the ARP data on your friends laptop, which MAC address is it? Your VM's or a different one?

It's too bad you can't do an ARP broadcast to ask each machine their MAC and IP address. Not that I know of anyway, maybe you can find something on Google.

[Bassi2k]

It's the MAC address of the VM. :/

[baf]

How does the netmask on each machine look?

[Sasquatch]

Very weird. I'm running Linux on my PC and laptop, have a VM with XP and I could ping it without issues from the laptop (VM runs on the PC). ARP showed the proper MAC too. How strange. Maybe it's a Windows Host thing.

@baf, it's DHCP, what do you think?

[baf]

Well I know how it should look. But I'm paranoid in these cases and want to be sure that it is correct.
I have seen dhcp-servers that were configured totally wrong and gave different masks to different clients.
So better safe then sorry.

[Sasquatch]

True, but we're not talking about company DHCP servers here, this is a standard household router we're dealing with. Hard to make DHCP config mistakes there.