D-Link DSR-150 User Manual page 118

Unified Services Router
User Manual
As well the encryption and integrity algorithms and keys must match on the remote
IPsec host exactly in order for the tunnel to establish successfully. Note that using
Auto policies with IKE are preferred as in some IPsec implementations the SPI
(security parameter index) values require conversion at each endpoint.
DSR supports VPN roll-over feature. This means that policies configured on primary
WAN will rollover to the secondary WAN in case of a link failure on a primary WAN.
This feature can be used only if your WAN is configured in Auto-Rollover mode.
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