Hello
I believe it to do the way Domain NAT works regarding inside and outside nat order.
Accessing the application via the internal subnet is fine as no nat is occurring however when you need to access the same application via its external natted address from within the internel lan itself the way nat is perform could be the problem.
My understanding of this may be incorrect, so I hope someone on these forums will be able to validate these next steps:
Domain NAT
Inside nat - routing perform before NAT
Outside nat - Nat perform before routing
1) packet is indicted from a inside lan towards a natted outside IP address
2) Outside NAT occurs and then RIB table lookup is performed then routed to destination inside ip
3 The returning packet performs a RIB table lookup first BEFORE NAT occurs and sees that the destination address is on its local subnet so nat is NOT initiated on the returning path and routes locally
4) The returning packet will be dropped because by the router sees the returning packet scr address is different then the natted address the router is expecting.
Domain-less NAT
2 routing lookups are performed before and after translation so the returning packet will be successful due to these rib lookups and translation being preformed the same in either direction.
FYI - I have labbed this up regards Domain-less Nat and it seems to work - please review the attached file.
As I have stated this may be incorrect and I hope someone else could validate this.
res
Paul
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Kind Regards
Paul
