Network Problem ( Network Access Drops)

This is for discussing general topics about how to use VirtualBox.
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DrunkenMaster
Posts: 4
Joined: 10. May 2019, 23:21

Network Problem ( Network Access Drops)

Post by DrunkenMaster »

So I am on a Mac,

I use a linux based app inside Virtual box. The manufracturer asks to use the Network Host Adapter. And it works.

So from my OS I can ping the Application in question. But if I connect my ethernet cable to an outside LAN, I loose the connection!

Any idea why??

Check this out so I am pinging the Virtual Machine :

64 bytes from 192.168.56.101: icmp_seq=11 ttl=64 time=0.239 ms
64 bytes from 192.168.56.101: icmp_seq=12 ttl=64 time=0.233 ms
64 bytes from 192.168.56.101: icmp_seq=13 ttl=64 time=0.233 ms
64 bytes from 192.168.56.101: icmp_seq=14 ttl=64 time=0.252 ms
64 bytes from 192.168.56.101: icmp_seq=15 ttl=64 time=0.227 ms
64 bytes from 192.168.56.101: icmp_seq=16 ttl=64 time=0.245 ms
64 bytes from 192.168.56.101: icmp_seq=17 ttl=64 time=0.217 ms
64 bytes from 192.168.56.101: icmp_seq=18 ttl=64 time=0.229 ms
64 bytes from 192.168.56.101: icmp_seq=19 ttl=64 time=0.250 ms
Request timeout for icmp_seq 20
Request timeout for icmp_seq 21
Request timeout for icmp_seq 22
Request timeout for icmp_seq 23


As soon as I connected my ethernet cable I lost access!

Whats happening?

Thanks!
BillG
Volunteer
Posts: 5102
Joined: 19. Sep 2009, 04:44
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows 10,7 and earlier
Location: Sydney, Australia

Re: Network Problem ( Network Access Drops)

Post by BillG »

I have no idea what is happening. What IP address does your ethernet adapter use?
Bill
DrunkenMaster
Posts: 4
Joined: 10. May 2019, 23:21

Re: Network Problem ( Network Access Drops)

Post by DrunkenMaster »

It's a static ip on the same range.

192.168.56.88
DrunkenMaster
Posts: 4
Joined: 10. May 2019, 23:21

Re: Network Problem ( Network Access Drops)

Post by DrunkenMaster »

Screen Shot 2019-05-11 at 20.43.09.png
Screen Shot 2019-05-11 at 20.43.09.png (39.73 KiB) Viewed 2063 times
check this out. this is the virtual machine system.

the ip is 192.168.56.101

unfortunately gets unreachable as soon as I plug my ethernet cable to do other jobs
BillG
Volunteer
Posts: 5102
Joined: 19. Sep 2009, 04:44
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows 10,7 and earlier
Location: Sydney, Australia

Re: Network Problem ( Network Access Drops)

Post by BillG »

Where did the 192.168.56.88 IP come from? Do you mean that the host is using 192.168.56.88 for its ethernet connection?? If it is, that would explain your problem. Your host has two interfaces (host only and ethernet) in different networks but in the same IP subnet.

If the host must use a 192.168.56.x address for its network connection, I would change the host only network to use a different subnet.
Bill
DrunkenMaster
Posts: 4
Joined: 10. May 2019, 23:21

Re: Network Problem ( Network Access Drops)

Post by DrunkenMaster »

Ok so...

Virtual Machine: 192.168.56.101 (default) 255.255.255.0
Ethernet Adapter 192.168.56.88 255.255.255.0

So your suggestion is to change the virtual machine subnet in the host adapter?

I was also trying to use bridged mode. But bridged mode leaves my VM with ip problem 0.0.0.0

Not sure if this is the case but my objective is this. Would be possible to design a scenario like this:

External PC - > . Ethernet Switch -> Host PC -> Virtual Machine
192.168.56.87 192.168.56.10 -> 192.168.56.88 -> 192.168.56.101

I use static ip addresses in all devices. My objective was to telnet and control VM with my External PC through the lan. And at a later stage with a Wifi Controller with a router attached to the switch.

The reason my external network is designed in the x.x.56.x range was to access this virtual machine address from external controllers via my switch. I am just experimenting

I am still getting into networks and trying to understand the problem. So the subnet would fix this? I thought that for peripherals to communicate in a network they had to be on the same range and subnet.

Thanks a ton!
BillG
Volunteer
Posts: 5102
Joined: 19. Sep 2009, 04:44
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows 10,7 and earlier
Location: Sydney, Australia

Re: Network Problem ( Network Access Drops)

Post by BillG »

Yes, for machines to communicate they must be in the same IP subnet. But they must also be in the same network. The host only network and the ethernet network are different networks. Why do you think that you need a host only adapter at all?

You can communicate between the host and guest if you use bridged mode, because the host and guest will be in the same network. (They will share the ethernet adapter in the host). The same goes for another physical machine on the same network (ie connected to the same switch). If you have a router with a DHCP server they will all get an IP address from there and work as if they were all physical machines on the LAN. If you don't have a router, give them IP addresses in the same IP subnet.
Bill
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