so hub & spoke VPN between 3 sites works fine
However if we need to tunnel from 1 spoke, thru spoke2 & to the central hub.
yes we have reasons, and it is not something i would normally do, i would just go spoke to hub, but that is not possible.. sometimes...
what is the best way? without SDwan
if the hub is 172.18.5.n, then it is not a simple case of just directing spoke2 to another spoke, since the return traffic from the hub would not know which is the endpoint. 1 or 2
do we need something like
hub real ->spoke1 dummy->nat->spoke1 dummy->spoke2
172.18.5.n->192.168.5.n->(NAT at spoke 1)->192.168.6.n->192.168.1.n
192.168.1.n->192.168.6.n->(NAT at spoke 1)->192.168.5.n->172.18.5.n
where 192.168.5.n & 192.168.6.n are dummies at spoke 1 used purely to ensure the traffic is correctly routed locally in spoke1 or passed thru to spoke 2
so traffic from spoke 2 hits a gateway in spoke 1 , is natted, then passed to another subnet for exit.
(since sonicwall will nto allow over lapping addresses)