How do crypto maps to different endpoints with the same interesting traffic ACLs behave?

[global-gossip]

Hi have the following situation:

A cloud providor offering L2L ipsec VPNs.

I have 3 offices globally.  They are currently all routable between each other via VPN links.

I want to introduce a new VPN from each office to the cloud providor offering up the same subnets over each VPN.  This would allow me to route to the cloud providor from any office over any one of the VPN links.

What happens in this situation by default?

SiteA

network 10.10.0.0/24

SiteB

network 10.20.0.0/24

SiteC

network 10.30.0.0/24

Cloud

network 192.168.0.0/24

Interesting traffic ACL at SiteA, SiteB and SiteC

permit ip 10.10.10.0 0.0.0.255 192.168.0.0 0.0.0.255

permit ip 10.10.20.0 0.0.0.255 192.168.0.0 0.0.0.255

permit ip 10.10.30.0 0.0.0.255 192.168.0.0 0.0.0.255

Assuming the tunnel from each site forms properly, how does it choose what VPN tunnel to send traffic over?  Can I get it to prefer one particular tunnel over another?

I realise that the best way to do this would be to run GRE over IPSec and use a routing protocol but unfortunately this is not possible as I don't have access to the cloud network.

Any suggestions welcome.

Thanks,

[Jouni Forss]

Hi,

Well I would imagine that each site would use their own L2L VPN connection.

If your goal would be to be able to use any of the L2L VPN connections towards the destination network then you would naturally have to do some special NAT configurations as the Cloud site cant have L2L VPN configurations for all of your sites network through multiple L2L VPN connections.

Then again when you consider the possible situation this would even help in.

In the case the Cloud site fails none of the offices can reach it anyway. In the case the local Internet connection to a site fails, so does the L2L VPN to the other site and the Cloud site. Unless ofcourse you have some dedicated connection between the offices AND an separate connection to the ISP?

- Jouni