VPN to colo: OpenVPN or IPSec

[mhab12]

Just like the title says, we'll be using the public internet for a site to site connection that will handle our backup each night (likely on a lowly 5mbps circuit).  Looking for input and suggestions on which tech to use.  We currently use OpenVPN for RoadWarrior connectivity if that makes any difference.  We'll also have Cisco switching gear available on both ends if IPSec via Cisco IOS is your preference.  Thanks for your input.

[cmb]

Generally doesn't matter either way. OpenVPN is easier to deal with if you have multiple non-contiguous subnets. Aside from that, with always-on static IP connectivity it's a toss up. OpenVPN is better in general at dealing with changing public IPs seamlessly because its negotiation process is much less complex but that wouldn't apply in this scenario (I would expect at least). It's easier to do redundant connectivity with a routing protocol with OpenVPN, so I run all my site to site connections to our datacenters with OpenVPN, as I can have one tunnel up on each WAN on my side and automatically switch between them if one connection goes down.