Anyone now what the issue is that would trigger an Error=9 when setting up an IPSec connection.

Phase 1 negotiation has no issue:

WAN2: Phase 1 of IKE negotiation succeeded. (Peers=y.y.y.y<->x.x.x.x)

But Phase 2 fails:

WAN2: Phase 2 of IKE negotiation failed. (Peers=y.y.y.y<->x.x.x.x, Error=9)

I have checked and both ends have the same Phase 2 parameters:

esp-md5-3des

I have connected Wireshart to the router and I can see all the ISAKMP messages.

I can read/decode all the Phase 1 messages, but of course all the phase 2 messages are encrypted so can't be decoded by Wireshark.

Interested in knowing what "Error=9" means so that I can figure out what part of phase 2 is failing.

Thanks.