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duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 2. Mar 2011, 17:19
by pwiggins
I've searched; albeit not well enough to find a solution for a deployment I'm sure others have done. Posting with a subject line that might help others in the future.

I'm finding that my VM's are ending up with the same Mac and DHCP IP address even though they are on and in different Virtualbox installs on different servers. I'm running multiple webservices within each VM and started off by using bridged connections from VM to Server.

At the moment I'm not running a DNS behind the firewall (haven't figured it all out yet).

This environment is behind a Verizon FIOS router; but will be moved to Comcast to enable port 80 and external connectivity to these Webservers.

I'm sure there's a cheat sheet.... just haven't found/figured it out yet. Any help is greatly appreciated.

End game is that all webservices can be accessed within all Servers/VBs/VMs...

Server1 (windows) running a single Virtualbox with multiple VM's.
VirtualBox1 4.0.4
VB1, VM1 (bridge mode to Server1 eth)
- mac ...25:55, ip 192.168.1.4


Server2 (windows) running single VirtualBox with multiple VM's.
VirtualBox2 3.2.1
VB2, VM1 (mode to Server2 wireless)
- mac ...25:55, ip 192.168.1.4

Thanks again.
Paul

Re: duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 2. Mar 2011, 17:22
by vbox4me2
Thats the nature of networking, every device weither its a real machine or a virtual machine, must have a unique IP address, when moving devices you must change that address to reflect whatever is used in the new location, there are no 2 ways about that. The same goes to some degree for Mac addresses.

Re: duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 2. Mar 2011, 17:51
by pwiggins
right. got it. thanks.
So... boiling it all down... how do you insure that subsequent VM's in running in different Virtualbox instances on different servers... all end up with unique MACs? I guess I could create a plan based on hardcoded MACs?

Re: duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 2. Mar 2011, 21:13
by vbox4me2
You can't basicly, the only thing you could try/do is research if a given Mac range is reserved for, for example some exotic country, and use that range hoping your VM's never get used in such exotic country. Behind router/firewalls its not an issue anymore since Mac addresses don't travel across.

Re: duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 3. Mar 2011, 00:07
by pwiggins
vmbox4me2- thanks so much for replying. Am I making this too hard perhaps? I read posts like

http://forums.virtualbox.org/viewtopic.php?f=7&t=22059

and he seems to of figured out how to create a small server farm running Virtualbox instances and multiple VM inside each; all happy and connected. Question is; am I'm not applying best practices?

thanks again for sticking with this...

Re: duplicate macs, ip addresses. Multiple servers, VBs, & VMs.

Posted: 3. Mar 2011, 15:04
by vbox4me2
There are no best practices for this scene other then asking whats being used at the destination.

A simple exampe of what I mean:
Just about every router comes pre-configured to use 192.168.1.x as your LAN range, when you want to use a VPN to the office and the office uses the same LAN range the vpn will fail, which is quite obvious why.