I need some help regarding network design. We have 40 branches , each other connected by MPLS and also to the data centre. Now we want redundant link to connect other branches with the data centre. Each branches and data centre also having internet link.
We want to use IPsec/GRE tunnel to the other branches with the DC.Now the questions are..
1)Is it possible to use VPN tunnel as a redundant link so that when MPLS goes down the only tunnel comes up?
2)If MPLS and tunnel both work simultaneously is there any chances to formed loop in the network?
3)How much internet link BW generally require for branches to connect with DC?
Please guide in this issue..