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Virtual network cluster issues: urgent help please

Posted: 14. Apr 2011, 08:24
by arramad
Hi everyone,
I have registered in here solely for this issue which I hope I can find a solution for it here...I am under limited time constraint so please the sooner help is the most appreciated:
I will try to make my situation clear so answers can be direct as much as possible.
I have Oracle linux 6 x64 bit host with three virtualbox VMs on it and all of them are with same exact OS. I use virtualbox 4.0.4
I have two ethernet cards on the host. I have made one down (ifconfig eth1 down) and using the only one that has connection (ifconfig eth0 up) and its dynamic.
I have the DNS server set up for all the three VM's names and IPs(all are static). Each VM has two bridged adapters, one public(eth0) and one for private network(eth1). I am buildign a cluster network between those three VMs and one of the requirements is to have internal network and public network thats why I have two adapters. my main issue is with the public one(eth0) that is supposed to be able to talk to the DNS server.
The resolv.conf is set in all VMs to include the correct DNS addresses and domain name.

Now, the issue can be summerized as the following:
A) from inside any of the VMs(rac1,rac2,rac3), the following works: (assume I am inside "rac2" now, and that rac1's IP= 132.241.18.7)

# ping 132.241.18.7
but it fails if I do:
# nslookup rac1
# nslookup 132.241.18.7
# ping rac1
# ping rac1.ecst.csuchico.edu
# ping http://www.google.com
B) from inside the host all the above work successfully.

C) from outside the host, pinging the host works using both the name and the IP
BUT pinging the VM doesn't work neither way!

my any help?

Re: Virtual network cluster issues: urgent help please

Posted: 14. Apr 2011, 08:42
by vbox4me2
Do a tracert and see where traffic is going from either side.

Re: Virtual network cluster issues: urgent help please

Posted: 14. Apr 2011, 21:49
by Sasquatch
And run tcpdump as well to see if you get any traffic flowing that you expect to get (like ICMP echo for ping).

You also have to think about the network itself. You turn off eth1 on the Host, yet still use it on the Guests. If you run ifconfig eth1 down before running any VM, it's quite possible the interface is back up and running and can cause strange things for the Guests. Either remove the bridged adapter, change it's attachment (change it to internal, host-only, not-attached (preferred), anything other than bridged) to rule out this is causing problems.

Re: Virtual network cluster issues: urgent help please

Posted: 22. Oct 2011, 21:42
by arramad
Thank you guys, and so sorry for the late response! I almost forgot about this post here (I had it in few other forums too)
I found that there was a block on my network port that I was taking access from (on the wall). It was set to only accept one MAC address at a time.
I talked to the network admin later about it and he said he forgot to fix it for me (even though I reminded him about at the beginning)
I thought someone else might go through it so here is the answer.