Hi @MarcW ,
Sounds like your non-Meraki peer is turning the tunnels off due to no activity.
Meraki devices send special DPD vpn packets to keep the tunnels alive when there's no traffic. However, not all VPN peers reply to DPD.
Therefore, the best way to keep site-to-site tunnels UP is generating interesting traffic - e.g.: a continuous ping from a host inside a local subnet into a destination at the other side.
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