I have just simulated the scenario and disconnected eth2 from the virtual box and nothing has changed, my SSH is still not working and the ping times out so its not worked unfortunately.
Please note that its always the primary slave that causes the issue, if during a healthy scenario i do a ifdown on eth4 (secondary slave) then there's no issue at the setup and it works merrily, its alway the primary slave going down that causes the issue.
I have since my last comment changed the eth settings of the underlying interfaces which makes up bond0 to remove a HW Address conflict error i was receiving in the message log (nothing to do with this issue but informing)...
I am using Oracle VM VirtualBox Manager .. and this is the second time am trying NIC bonding on the same env (it worked earlier) however i purged teh setup in favour of something else and while now resurrecting getting this situation now, don't beleive the env's a problem when it worked on the same setup earlier.
The NICs are setup in "Host only Adapter mode" ..
Not sure if i should try once in the "internal network" mode - although i think i'll lose the host to guest connectivity via Putty in that case..
I would have to look into more details about bonding and teaming and such, but such technologies often require that each NIC is attached to a separate network switch to avoid ARP (Hardware address) conflicts and possible spanning tree protocol issues.
Your problem might be due to the way VirtualBox deals with the host-only adapter internally, which is actually a virtual adapter on your host system. You may have more luck using a bridged type network adapter, which binds to a real NIC and can also be setup to bind to a specific adapter on the host system.
I suggest to search or try the VirtualBox forum at https://forums.virtualbox.org/
The VirtualBox forum are not necessarily Linux experts. It might be a good idea to shed some light on the VirtualBox adapter type to find out if there are certain limitations. Hiding that you are using the host-only adapter won't help you to find a solution if it is indeed the problem. It might also be a good idea to provide a link to this thread in your post to show people that you have already check the Linux configuration part.
Hi, Yes agree.. have amended the post to include the details + a link to this thread (didn't include it first hand as they a rule of not allowing new members to post links until they are 1 day old :) )