All that done, it works now, but I may have configured wrong.
Regarding NAT configuration (Firewall > NAT > Outbound), mine was set to "Automatic outbound NAT rule generation (IPsec passthrough included)". This was its default configuration, I had never touched it. All what it did had been generated automatically. It contained three pairs of rules (total 6 rules), related respectively to the 127.0.0.0 /8 source (whatever that may be) and my two VLANS. Then, the instruction was to add a new outbound NAT rule. Specifically: (1) switch to "Manual outbound NAT" ; (2) create the ModemAccess new outbound NAT rule ; (3) save. Now, my Firewall > NAT > Outbound configuration is set to "Manual Outbound NAT rule generation (AON - Advanced Outbound NAT)". The screen shot below shows that I have now my original 6 automated rules plus the one that I manually added.
I still do not know the role of the initial 6 automated rules and would be perfectly unable to determine when this set of rules would need to be changed. For that reason, it seems to me I would be better off switching now to "Hybrid Outbound NAT rule generation (Automatic Outbound NAT + rules below)", thus preserving the one manual rule that I created, the former 6 automated rules that were formerly generated automatically, plus any additions (or changes) to my initial 6 automated rules.
To which extent is my thinking wrong ?
Any advice on this would be welcome. TIA.
2018-02-22_OutboundNATrules.png
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