OK - personally I would have the security level to 50 - then I know
My inside is 100 = totally trusted
My outside is 0 = totally un-trusted
My VLAN100 is 50 = can access the internet, but I need to write an acl for traffic originating in the VLAN100 to the inside.
You must look at your NAT - bu default all traffic passing from a lower interface to a higher and vice versa is natt'ed.
So I would have something likeP:-
global (outside) 1 interface
nat (inside) 1 w.w.w.w x.x.x.x
nat (VLAN100) 1 y.y.y.y z.z.z.z
The above will NAT all traffic to the internet using the outside IP address, then the nat exemption
access-list no-nat permit ip w.w.w.w x.x.x.x y.y.y.y z.z.z.z
access-list no-nat-permit ip y.y.y.y z.z.z.z w.w.w.w x.x.x.x
nat (inside) 0 access-list no-nat
nat (VLAN100) 0 access-list no-nat
The above tells the firewall not to nat when the source and destinatiobn match = everything else should be natt'ed.
w.w.w.w x.x.x.x = VLAN 71 IP subnet & mask
y.y.y.y z.z.z.z = VLAN100 IP subnet & mask
Then you need to allow access from server to server
access-list allow-server permit ip host 10.100.10.1 host 10.71.100.136
access-group allow-server in interface VLAN100
HTH>
