Classifies the peer of this Permanent Tunnel as a regular fixed-IP gateway, a DAIP gateway, or a ROBO branch gateway. A permanent tunnel configured against a DAIP peer is somewhat unusual, since permanent tunnels are typically set up against stable, fixed-IP partners specifically because they need to stay continuously reachable, so seeing daip here is worth double-checking against the intended design, since a peer whose address can change undermines the guarantee a permanent tunnel is meant to provide. Example: discovering permanentTunnelPeerType reports daip(2) for what was assumed to be a fixed data-center peer would explain occasional unexpected renegotiations of a link that's supposed to never need to re-resolve its peer.