IPsec Tunnel Configuration Issue - Overlapping Subnets

[Yahia]

Hello

I am encountering an issue when attempting to create an IPsec tunnel with a Non-Meraki peer. I received the following notification:

The settings you requested require confirmation. Please review the following list: - The VLAN subnets 10.2.2.0/24, 10.40.40.0/24, 10.50.50.0/28, 10.33.33.0/24, and 10.44.44.0/24 overlap with a remote VPN subnet on the Non-Meraki peer Tunnel-1 (10.0.0.0/8). IP traffic will be routed to the smallest subnet that contains the IP address. - A subnet on the Non-Meraki peer Tunnel-1 (10.0.0.0/8) overlaps with subnets on the network Estarta TAC - appliance (10.238.70.0/24, 10.238.71.0/24, 10.238.76.0/23, and 10.238.78.0/24). IP traffic will be routed to the smallest subnet that contains the IP address. Could you please clarify why this notification appears and whether creating the tunnel will have any impact on the network or routing due to this overlap?

Please note that Tunnel-1 is configured on the "X" network, while I am planning to create a new tunnel on the "Y" network. It's important to mention that the two networks are completely separate and have no direct connection with each other 

[ww · Accepted solution]

It more a informational notification.  

https://documentation.meraki.com/MX/Networks_and_Routing/MX_Routing_Behavior#Overlapping_Routes

The router will first use routes to  10.238.70.0/24, 10.238.71.0/24, 10.238.76.0/23, and 10.238.78.0/24   

All other 10.x.x.x destinations wil be routed to the new tunnel

[Yahia]

Please note the a new tunnel on the different MX and network

[alemabrahao]

Do you have any other tunnel or within the SD Wan tunnel that is configured to use the 10.0.0.0/8 network? If you have and are configuring a new tunnel with more specific networks, the routing will have priority for the more specific networks. Can you please share a screenshot?

[Yahia]

I have two MX each MX in the sperate network 

MX-1 have Tunnel-1 remote site IP 10.0.0.0\8

MX-2 I want to create new tunnel to non-meraki device remote site IP 192.168.150.0\24

[PhilipDAth]

Note that when you configure a non-Meraki VPN is is done on *every* network, unless you use tags.  To be 100% clear, it is not done on just the currently selected network.

Refer to step 9.

https://documentation.meraki.com/MX/Site-to-site_VPN/Site-to-Site_VPN_Settings#Non-Meraki_VPN_Peers

[Yahia]

*"Network 1 has an MX security appliance with an established VPN tunnel to another site. Now, I want to create a new VPN tunnel from Network 2 (which also has its own MX appliance) to a different site — without any connection or dependency on Network 1's MX or its tunnels.

However, when I try to save the new tunnel configuration in Network 2, a warning message appears. This message is only a warning and does not prevent saving the configuration.